[RFC PATCH v3 1/6] drm/doc: Color Management and HDR10 RFC
Harry Wentland
harry.wentland at amd.com
Fri Jul 30 20:41:29 UTC 2021
Use the new DRM RFC doc section to capture the RFC previously only
described in the cover letter at
https://patchwork.freedesktop.org/series/89506/
v3:
* Add sections on single-plane and multi-plane HDR
* Describe approach to define HW details vs approach to define SW intentions
* Link Jeremy Cline's excellent HDR summaries
* Outline intention behind overly verbose doc
* Describe FP16 use-case
* Clean up links
v2: create this doc
v1: n/a
Signed-off-by: Harry Wentland <harry.wentland at amd.com>
---
Documentation/gpu/rfc/color_intentions.drawio | 1 +
Documentation/gpu/rfc/color_intentions.svg | 3 +
Documentation/gpu/rfc/colorpipe | 1 +
Documentation/gpu/rfc/colorpipe.svg | 3 +
Documentation/gpu/rfc/hdr-wide-gamut.rst | 580 ++++++++++++++++++
Documentation/gpu/rfc/index.rst | 1 +
6 files changed, 589 insertions(+)
create mode 100644 Documentation/gpu/rfc/color_intentions.drawio
create mode 100644 Documentation/gpu/rfc/color_intentions.svg
create mode 100644 Documentation/gpu/rfc/colorpipe
create mode 100644 Documentation/gpu/rfc/colorpipe.svg
create mode 100644 Documentation/gpu/rfc/hdr-wide-gamut.rst
diff --git a/Documentation/gpu/rfc/color_intentions.drawio b/Documentation/gpu/rfc/color_intentions.drawio
new file mode 100644
index 000000000000..d62f3b24e1ec
--- /dev/null
+++ b/Documentation/gpu/rfc/color_intentions.drawio
@@ -0,0 +1 @@
+<mxfile host="Electron" modified="2021-07-27T17:06:00.446Z" agent="5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) draw.io/14.6.13 Chrome/91.0.4472.124 Electron/13.1.7 Safari/537.36" etag="5FhBvRxDzJPI4Jsj_73y" version="14.6.13" type="device"><diagram id="5iAH_SKWfpT4d7aif5q5" name="Page-1">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</diagram></mxfile>
\ No newline at end of file
diff --git a/Documentation/gpu/rfc/color_intentions.svg b/Documentation/gpu/rfc/color_intentions.svg
new file mode 100644
index 000000000000..2f6b5f5813a3
--- /dev/null
+++ b/Documentation/gpu/rfc/color_intentions.svg
@@ -0,0 +1,3 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" width="242px" height="362px" viewBox="-0.5 -0.5 242 362" content="<mxfile host="Electron" modified="2021-07-27T15:46:56.623Z" agent="5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) draw.io/14.6.13 Chrome/91.0.4472.124 Electron/13.1.7 Safari/537.36" etag="yRHplrf8g5DRVJVrDlPI" version="14.6.13" type="device"><diagram id="5iAH_SKWfpT4d7aif5q5" name="Page-1">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</diagram></mxfile>" style="background-color: rgb(255, 255, 255);"><defs/><g><path d="M 58.07 88 L 58.15 139.95" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 58.16 145.2 L 54.65 138.21 L 58.15 139.95 L 61.65 138.2 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><rect x="8" y="8" width="100" height="80" fill="#ffffff" stroke="#000000" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe flex-start; width: 98px; height: 1px; padding-top: 48px; margin-left: 10px;"><div style="box-sizing: border-box; font-size: 0; text-align: left; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; "><div style="text-align: center"><span>Framebuffer</span></div><div><ul><li><span>RGB8</span></li><li><span>sRGB</span></li></ul></div></div></div></div></foreignObject><text x="10" y="52" fill="#000000" font-family="Helvetica" font-size="12px">Framebuffer...</text></switch></g><path d="M 118 208 L 118 241.63" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 118 246.88 L 114.5 239.88 L 118 241.63 L 121.5 239.88 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><rect x="8" y="148" width="220" height="60" fill="#ffffff" stroke="#000000" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 218px; height: 1px; padding-top: 178px; margin-left: 9px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; ">Blending</div></div></div></foreignObject><text x="118" y="182" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">Blending</text></switch></g><path d="M 178.54 108 L 178.87 138.27" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 178.93 143.52 L 175.35 136.56 L 178.87 138.27 L 182.35 136.48 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><rect x="128" y="8" width="100" height="100" fill="#ffffff" stroke="#000000" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 98px; height: 1px; padding-top: 58px; margin-left: 129px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; ">Framebuffer<br /><ul><li style="text-align: left">P010</li><li style="text-align: left">PQ</li><li style="text-align: left">BT2020</li></ul></div></div></div></foreignObject><text x="178" y="62" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">Framebuffer...</text></switch></g><rect x="68" y="248" width="100" height="100" fill="#ffffff" stroke="#000000" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 98px; height: 1px; padding-top: 298px; margin-left: 69px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; ">Display Output<br /><ul><li style="text-align: left">RGB10</li><li style="text-align: left">PQ</li><li style="text-align: left">BT2020</li></ul></div></div></div></foreignObject><text x="118" y="302" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">Display Output...</text></switch></g></g><switch><g requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"/><a transform="translate(0,-5)" xlink:href="https://www.diagrams.net/doc/faq/svg-export-text-problems" target="_blank"><text text-anchor="middle" font-size="10px" x="50%" y="100%">Viewer does not support full SVG 1.1</text></a></switch></svg>
\ No newline at end of file
diff --git a/Documentation/gpu/rfc/colorpipe b/Documentation/gpu/rfc/colorpipe
new file mode 100644
index 000000000000..2d12490eddec
--- /dev/null
+++ b/Documentation/gpu/rfc/colorpipe
@@ -0,0 +1 @@
+<mxfile host="Electron" modified="2021-07-27T14:17:36.119Z" agent="5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) draw.io/14.6.13 Chrome/91.0.4472.124 Electron/13.1.7 Safari/537.36" etag="Gs2TTWVtoGmka55_Cxxx" version="14.6.13" type="device"><diagram id="5iAH_SKWfpT4d7aif5q5" name="Page-1">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</diagram></mxfile>
\ No newline at end of file
diff --git a/Documentation/gpu/rfc/colorpipe.svg b/Documentation/gpu/rfc/colorpipe.svg
new file mode 100644
index 000000000000..f6b8ece2499d
--- /dev/null
+++ b/Documentation/gpu/rfc/colorpipe.svg
@@ -0,0 +1,3 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" width="241px" height="657px" viewBox="-0.5 -0.5 241 657" content="<mxfile host="Electron" modified="2021-07-27T14:17:39.137Z" agent="5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) draw.io/14.6.13 Chrome/91.0.4472.124 Electron/13.1.7 Safari/537.36" etag="ffS0jb-Ry8iliDxn_T30" version="14.6.13" type="device"><diagram id="5iAH_SKWfpT4d7aif5q5" name="Page-1">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</diagram></mxfile>" style="background-color: rgb(255, 255, 255);"><defs/><g><path d="M 58 58 L 58 81.63" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 58 86.88 L 54.5 79.88 L 58 81.63 L 61.5 79.88 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><rect x="8" y="8" width="100" height="50" fill="#ffffff" stroke="#000000" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 98px; height: 1px; padding-top: 33px; margin-left: 9px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; ">Framebuffer</div></div></div></foreignObject><text x="58" y="37" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">Framebuffer</text></switch></g><path d="M 58 128 L 58 151.63" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 58 156.88 L 54.5 149.88 L 58 151.63 L 61.5 149.88 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><rect x="8" y="88" width="100" height="40" fill="#ffffff" stroke="#000000" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 98px; height: 1px; padding-top: 108px; margin-left: 9px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; ">de-YUV matrix</div></div></div></foreignObject><text x="58" y="112" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">de-YUV matrix</text></switch></g><path d="M 58 198 L 58 221.63" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 58 226.88 L 54.5 219.88 L 58 221.63 L 61.5 219.88 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><rect x="8" y="158" width="100" height="40" fill="#ffffff" stroke="#000000" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 98px; height: 1px; padding-top: 178px; margin-left: 9px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; ">(de-Gamma)<br />LUT</div></div></div></foreignObject><text x="58" y="182" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">(de-Gamma)...</text></switch></g><path d="M 58 268 L 58 296.63" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 58 301.88 L 54.5 294.88 L 58 296.63 L 61.5 294.88 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><rect x="8" y="228" width="100" height="40" fill="#ffffff" stroke="#000000" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 98px; height: 1px; padding-top: 248px; margin-left: 9px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; ">CTM / CSC</div></div></div></foreignObject><text x="58" y="252" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">CTM / CSC</text></switch></g><path d="M 58 343 L 57.46 362.47" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 57.31 367.72 L 54.01 360.63 L 57.46 362.47 L 61 360.82 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><rect x="8" y="303" width="100" height="40" fill="#ffffff" stroke="#000000" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 98px; height: 1px; padding-top: 323px; margin-left: 9px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; ">Tonemapping</div></div></div></foreignObject><text x="58" y="327" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">Tonemapping</text></switch></g><path d="M 118 428 L 118 451.63" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 118 456.88 L 114.5 449.88 L 118 451.63 L 121.5 449.88 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><rect x="8" y="368" width="220" height="60" fill="#ffffff" stroke="#000000" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 218px; height: 1px; padding-top: 398px; margin-left: 9px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; ">Blending</div></div></div></foreignObject><text x="118" y="402" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">Blending</text></switch></g><path d="M 178 58 L 178 81.63" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 178 86.88 L 174.5 79.88 L 178 81.63 L 181.5 79.88 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><rect x="128" y="8" width="100" height="50" fill="#ffffff" stroke="#000000" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 98px; height: 1px; padding-top: 33px; margin-left: 129px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; ">Framebuffer</div></div></div></foreignObject><text x="178" y="37" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">Framebuffer</text></switch></g><path d="M 178 128 L 178 151.63" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 178 156.88 L 174.5 149.88 L 178 151.63 L 181.5 149.88 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><rect x="128" y="88" width="100" height="40" fill="#ffffff" stroke="#000000" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 98px; height: 1px; padding-top: 108px; margin-left: 129px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; ">de-YUV matrix</div></div></div></foreignObject><text x="178" y="112" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">de-YUV matrix</text></switch></g><path d="M 178 198 L 178 221.63" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 178 226.88 L 174.5 219.88 L 178 221.63 L 181.5 219.88 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><rect x="128" y="158" width="100" height="40" fill="#ffffff" stroke="#000000" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 98px; height: 1px; padding-top: 178px; margin-left: 129px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; ">(de-Gamma)<br />LUT</div></div></div></foreignObject><text x="178" y="182" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">(de-Gamma)...</text></switch></g><path d="M 178 268 L 178 296.63" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 178 301.88 L 174.5 294.88 L 178 296.63 L 181.5 294.88 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><rect x="128" y="228" width="100" height="40" fill="#ffffff" stroke="#000000" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 98px; height: 1px; padding-top: 248px; margin-left: 129px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; ">CTM / CSC</div></div></div></foreignObject><text x="178" y="252" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">CTM / CSC</text></switch></g><path d="M 178 343 L 178.71 362.48" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 178.9 367.72 L 175.15 360.85 L 178.71 362.48 L 182.14 360.6 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><rect x="128" y="303" width="100" height="40" fill="#ffffff" stroke="#000000" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 98px; height: 1px; padding-top: 323px; margin-left: 129px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; ">Tonemapping</div></div></div></foreignObject><text x="178" y="327" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">Tonemapping</text></switch></g><path d="M 118 498 L 118 521.63" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 118 526.88 L 114.5 519.88 L 118 521.63 L 121.5 519.88 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><rect x="68" y="458" width="100" height="40" fill="#ffffff" stroke="#000000" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 98px; height: 1px; padding-top: 478px; margin-left: 69px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; ">(Tonemapping)<br />LUT</div></div></div></foreignObject><text x="118" y="482" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">(Tonemapping)...</text></switch></g><path d="M 118 568 L 118 596.63" fill="none" stroke="#000000" stroke-miterlimit="10" pointer-events="stroke"/><path d="M 118 601.88 L 114.5 594.88 L 118 596.63 L 121.5 594.88 Z" fill="#000000" stroke="#000000" stroke-miterlimit="10" pointer-events="all"/><rect x="68" y="528" width="100" height="40" fill="#ffffff" stroke="#000000" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 98px; height: 1px; padding-top: 548px; margin-left: 69px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; ">CTM / CSC</div></div></div></foreignObject><text x="118" y="552" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">CTM / CSC</text></switch></g><rect x="68" y="603" width="100" height="40" fill="#ffffff" stroke="#000000" pointer-events="all"/><g transform="translate(-0.5 -0.5)"><switch><foreignObject style="overflow: visible; text-align: left;" pointer-events="none" width="100%" height="100%" requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"><div xmlns="http://www.w3.org/1999/xhtml" style="display: flex; align-items: unsafe center; justify-content: unsafe center; width: 98px; height: 1px; padding-top: 623px; margin-left: 69px;"><div style="box-sizing: border-box; font-size: 0; text-align: center; "><div style="display: inline-block; font-size: 12px; font-family: Helvetica; color: #000000; line-height: 1.2; pointer-events: all; white-space: normal; word-wrap: normal; ">(Gamma)<br />LUT</div></div></div></foreignObject><text x="118" y="627" fill="#000000" font-family="Helvetica" font-size="12px" text-anchor="middle">(Gamma)...</text></switch></g></g><switch><g requiredFeatures="http://www.w3.org/TR/SVG11/feature#Extensibility"/><a transform="translate(0,-5)" xlink:href="https://www.diagrams.net/doc/faq/svg-export-text-problems" target="_blank"><text text-anchor="middle" font-size="10px" x="50%" y="100%">Viewer does not support full SVG 1.1</text></a></switch></svg>
\ No newline at end of file
diff --git a/Documentation/gpu/rfc/hdr-wide-gamut.rst b/Documentation/gpu/rfc/hdr-wide-gamut.rst
new file mode 100644
index 000000000000..e463670191ab
--- /dev/null
+++ b/Documentation/gpu/rfc/hdr-wide-gamut.rst
@@ -0,0 +1,580 @@
+==============================
+HDR & Wide Color Gamut Support
+==============================
+
+.. role:: wy-text-strike
+
+ToDo
+====
+
+* :wy-text-strike:`Reformat as RST kerneldoc` - done
+* :wy-text-strike:`Don't use color_encoding for color_space definitions` - done
+* :wy-text-strike:`Update SDR luminance description and reasoning` - done
+* :wy-text-strike:`Clarify 3D LUT required for some color space transformations` - done
+* :wy-text-strike:`Highlight need for named color space and EOTF definitions` - done
+* :wy-text-strike:`Define transfer function API` - done
+* :wy-text-strike:`Draft upstream plan` - done
+* :wy-text-strike:`Reference to wayland plan` - done
+* Reference to Chrome plans
+* Sketch view of HW pipeline for couple of HW implementations
+
+
+Upstream Plan
+=============
+
+* Reach consensus on DRM/KMS API
+* Implement support in amdgpu
+* Implement IGT tests
+* Add API support to Weston, ChromiumOS, or other canonical open-source project interested in HDR
+* Merge user-space
+* Merge kernel patches
+
+
+History
+=======
+
+v3:
+
+* Add sections on single-plane and multi-plane HDR
+* Describe approach to define HW details vs approach to define SW intentions
+* Link Jeremy Cline's excellent HDR summaries
+* Outline intention behind overly verbose doc
+* Describe FP16 use-case
+* Clean up links
+
+v2: create this doc
+
+v1: n/a
+
+
+Introduction
+============
+
+We are looking to enable HDR support for a couple of single-plane and
+multi-plane scenarios. To do this effectively we recommend new interfaces
+to drm_plane. Below I'll give a bit of background on HDR and why we
+propose these interfaces.
+
+As an RFC doc this document is more verbose than what we would want from
+an eventual uAPI doc. This is intentional in order to ensure interested
+parties are all on the same page and to facilitate discussion if there
+is disagreement on aspects of the intentions behind the proposed uAPI.
+
+
+Overview and background
+=======================
+
+I highly recommend you read `Jeremy Cline's HDR primer`_
+
+Jeremy Cline did a much better job describing this. I highly recommend
+you read it at [1]:
+
+.. _Jeremy Cline's HDR primer: https://www.jcline.org/blog/fedora/graphics/hdr/2021/05/07/hdr-in-linux-p1.html
+
+Defining a pixel's luminance
+----------------------------
+
+The luminance space of pixels in a framebuffer/plane presented to the
+display is not well defined in the DRM/KMS APIs. It is usually assumed to
+be in a 2.2 or 2.4 gamma space and has no mapping to an absolute luminance
+value; it is interpreted in relative terms.
+
+Luminance can be measured and described in absolute terms as candela
+per meter squared, or cd/m2, or nits. Even though a pixel value can be
+mapped to luminance in a linear fashion to do so without losing a lot of
+detail requires 16-bpc color depth. The reason for this is that human
+perception can distinguish roughly between a 0.5-1% luminance delta. A
+linear representation is suboptimal, wasting precision in the highlights
+and losing precision in the shadows.
+
+A gamma curve is a decent approximation to a human's perception of
+luminance, but the `PQ (perceptual quantizer) function`_ improves on
+it. It also defines the luminance values in absolute terms, with the
+highest value being 10,000 nits and the lowest 0.0005 nits.
+
+Using a content that's defined in PQ space we can approximate the real
+world in a much better way.
+
+Here are some examples of real-life objects and their approximate
+luminance values:
+
+
+.. _PQ (perceptual quantizer) function: https://en.wikipedia.org/wiki/High-dynamic-range_video#Perceptual_Quantizer
+
+.. flat-table::
+ :header-rows: 1
+
+ * - Object
+ - Luminance in nits
+
+ * - Fluorescent light
+ - 10,000
+
+ * - Highlights
+ - 1,000 - sunlight
+
+ * - White Objects
+ - 250 - 1,000
+
+ * - Typical Objects
+ - 1 - 250
+
+ * - Shadows
+ - 0.01 - 1
+
+ * - Ultra Blacks
+ - 0 - 0.0005
+
+
+Transfer functions
+------------------
+
+Traditionally we used the terms gamma and de-gamma to describe the
+encoding of a pixel's luminance value and the operation to transfer from
+a linear luminance space to the non-linear space used to encode the
+pixels. Since some newer encodings don't use a gamma curve I suggest
+we refer to non-linear encodings using the terms `EOTF, and OETF`_, or
+simply as transfer function in general.
+
+The EOTF (Electro-Optical Transfer Function) describes how to transfer
+from an electrical signal to an optical signal. This was traditionally
+done by the de-gamma function.
+
+The OETF (Opto Electronic Transfer Function) describes how to transfer
+from an optical signal to an electronic signal. This was traditionally
+done by the gamma function.
+
+More generally we can name the transfer function describing the transform
+between scanout and blending space as the **input transfer function**, and
+the transfer function describing the transform from blending space to the
+output space as **output transfer function**.
+
+
+.. _EOTF, and OETF: https://en.wikipedia.org/wiki/Transfer_functions_in_imaging
+
+Mastering Luminances
+--------------------
+
+Even though we are able to describe the absolute luminance of a pixel
+using the PQ 2084 EOTF we are presented with physical limitations of the
+display technologies on the market today. Here are a few examples of
+luminance ranges of displays.
+
+.. flat-table::
+ :header-rows: 1
+
+ * - Display
+ - Luminance range in nits
+
+ * - Typical PC display
+ - 0.3 - 200
+
+ * - Excellent LCD HDTV
+ - 0.3 - 400
+
+ * - HDR LCD w/ local dimming
+ - 0.05 - 1,500
+
+Since no display can currently show the full 0.0005 to 10,000 nits
+luminance range of PQ the display will need to tone-map the HDR content,
+i.e to fit the content within a display's capabilities. To assist
+with tone-mapping HDR content is usually accompanied by a metadata
+that describes (among other things) the minimum and maximum mastering
+luminance, i.e. the maximum and minimum luminance of the display that
+was used to master the HDR content.
+
+The HDR metadata is currently defined on the drm_connector via the
+hdr_output_metadata blob property.
+
+It might be useful to define per-plane hdr metadata, as different planes
+might have been mastered differently.
+
+.. _SDR Luminance:
+
+SDR Luminance
+-------------
+
+Traditional SDR content's maximum white luminance is not well defined.
+Some like to define it at 80 nits, others at 200 nits. It also depends
+to a large extent on the environmental viewing conditions. In practice
+this means that we need to define the maximum SDR white luminance, either
+in nits, or as a ratio.
+
+`One Windows API`_ defines it as a ratio against 80 nits.
+
+`Another Windows API`_ defines it as a nits value.
+
+The `Wayland color management proposal`_ uses Apple's definition of EDR as a
+ratio of the HDR range vs SDR range.
+
+If a display's maximum HDR white level is correctly reported it is trivial
+to convert between all of the above representations of SDR white level. If
+it is not, defining SDR luminance as a nits value, or a ratio vs a fixed
+nits value is preferred, assuming we are blending in linear space.
+
+It is our experience that many HDR displays do not report maximum white
+level correctly
+
+.. _One Windows API: https://docs.microsoft.com/en-us/windows-hardware/drivers/ddi/dispmprt/ns-dispmprt-_dxgkarg_settargetadjustedcolorimetry2
+.. _Another Windows API: https://docs.microsoft.com/en-us/uwp/api/windows.graphics.display.advancedcolorinfo.sdrwhitelevelinnits?view=winrt-20348
+.. _Wayland color management proposal: https://gitlab.freedesktop.org/swick/wayland-protocols/-/blob/color/unstable/color-management/color.rst#id8
+
+Let There Be Color
+------------------
+
+So far we've only talked about luminance, ignoring colors altogether. Just
+like in the luminance space, traditionally the color space of display
+outputs has not been well defined. Similar to how an EOTF defines a
+mapping of pixel data to an absolute luminance value, the color space
+maps color information for each pixel onto the CIE 1931 chromaticity
+space. This can be thought of as a mapping to an absolute, real-life,
+color value.
+
+A color space is defined by its primaries and white point. The primaries
+and white point are expressed as coordinates in the CIE 1931 color
+space. Think of the red primary as the reddest red that can be displayed
+within the color space. Same for green and blue.
+
+Examples of color spaces are:
+
+.. flat-table::
+ :header-rows: 1
+
+ * - Color Space
+ - Description
+
+ * - BT 601
+ - similar to BT 709
+
+ * - BT 709
+ - used by sRGB content; ~53% of BT 2020
+
+ * - DCI-P3
+ - used by most HDR displays; ~72% of BT 2020
+
+ * - BT 2020
+ - standard for most HDR content
+
+
+
+Color Primaries and White Point
+-------------------------------
+
+Just like displays can currently not represent the entire 0.0005 -
+10,000 nits HDR range of the PQ 2084 EOTF, they are currently not capable
+of representing the entire BT.2020 color Gamut. For this reason video
+content will often specify the color primaries and white point used to
+master the video, in order to allow displays to be able to map the image
+as best as possible onto the display's gamut.
+
+
+Displays and Tonemapping
+------------------------
+
+External displays are able to do their own tone and color mapping, based
+on the mastering luminance, color primaries, and white space defined in
+the HDR metadata.
+
+Some internal panels might not include the complex HW to do tone and color
+mapping on their own and will require the display driver to perform
+appropriate mapping.
+
+
+How are we solving the problem?
+===============================
+
+Single-plane
+------------
+
+If a single drm_plane is used no further work is required. The compositor
+will provide one HDR plane alongside a drm_connector's hdr_output_metadata
+and the display HW will output this plane without further processing if
+no CRTC LUTs are provided.
+
+If desired a compositor can use the CRTC LUTs for HDR content but without
+support for PWL or multi-segmented LUTs the quality of the operation is
+expected to be subpar for HDR content.
+
+
+Multi-plane
+-----------
+
+In multi-plane configurations we need to solve the problem of blending
+HDR and SDR content. This blending should be done in linear space and
+therefore requires framebuffer data that is presented in linear space
+or a way to convert non-linear data to linear space. Additionally
+we need a way to define the luminance of any SDR content in relation
+to the HDR content.
+
+In order to present framebuffer data in linear space without losing a
+lot of precision it needs to be presented using 16 bpc precision.
+
+
+Defining HW Details
+-------------------
+
+One way to take full advantage of modern HW's color pipelines is by
+defining a "generic" pipeline that matches all capable HW. Something
+like this, which I took `from Uma Shankar`_ and expanded on:
+
+.. _from Uma Shankar: https://patchwork.freedesktop.org/series/90826/
+
+.. kernel-figure:: colorpipe.svg
+
+I intentionally put de-Gamma, and Gamma in parentheses in my graph
+as they describe the intention of the block but not necessarily a
+strict definition of how a userspace implementation is required to
+use them.
+
+De-Gamma and Gamma blocks are named LUT, but they could be non-programmable
+LUTs in some HW implementations with no programmable LUT available. See
+the definitions for AMD's `latest dGPU generation`_ as an example.
+
+.. _latest dGPU generation: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_resource.c?h=v5.13#n2586
+
+I renamed the "Plane Gamma LUT" and "CRTC De-Gamma LUT" to "Tonemapping"
+as we generally don't want to re-apply gamma before blending, or do
+de-gamma post blending. These blocks tend generally to be intended for
+tonemapping purposes.
+
+Tonemapping in this case could be a simple nits value or `EDR`_ to describe
+how to scale the :ref:`SDR luminance`.
+
+Tonemapping could also include the ability to use a 3D LUT which might be
+accompanied by a 1D shaper LUT. The shaper LUT is required in order to
+ensure a 3D LUT with limited entries (e.g. 9x9x9, or 17x17x17) operates
+in perceptual (non-linear) space, so as to evenly spread the limited
+entries evenly across the perceived space.
+
+.. _EDR: https://gitlab.freedesktop.org/swick/wayland-protocols/-/blob/color/unstable/color-management/color.rst#id8
+
+Creating a model that is flexible enough to define color pipelines for
+a wide variety of HW is challenging, though not impossible. Implementing
+support for such a flexible definition in userspace, though, amounts
+to essentially writing color pipeline drivers for each HW.
+
+
+Defining SW Intentions
+----------------------
+
+An alternative to describing the HW color pipeline in enough detail to
+be useful for color management and HDR purposes is to instead define
+SW intentions.
+
+.. kernel-figure:: color_intentions.svg
+
+This greatly simplifies the API and lets the driver do what a driver
+does best: figure out how to program the HW to achieve the desired
+effect.
+
+The above diagram could include white point, primaries, and maximum
+peak and average white levels in order to facilitate tone mapping.
+
+At this point I suggest to keep tonemapping (other than an SDR luminance
+adjustment) out of the current DRM/KMS API. Most HDR displays are capable
+of tonemapping. If for some reason tonemapping is still desired on
+a plane, a shader might be a better way of doing that instead of relying
+on display HW.
+
+In some ways this mirrors how various userspace APIs treat HDR:
+ * Gstreamer's `GstVideoTransferFunction`_
+ * EGL's `EGL_EXT_gl_colorspace_bt2020_pq`_ extension
+ * Vulkan's `VkColorSpaceKHR`_
+
+.. _GstVideoTransferFunction: https://gstreamer.freedesktop.org/documentation/video/video-color.html?gi-language=c#GstVideoTransferFunction
+.. _EGL_EXT_gl_colorspace_bt2020_pq: https://www.khronos.org/registry/EGL/extensions/EXT/EGL_EXT_gl_colorspace_bt2020_linear.txt
+.. _VkColorSpaceKHR: https://www.khronos.org/registry/vulkan/specs/1.2-extensions/html/vkspec.html#VkColorSpaceKHR
+
+
+A hybrid approach to the API
+----------------------------
+
+Our current approach attempts a hybrid approach, defining API to specify
+input and output transfer functions, as well as an SDR boost, and a
+input color space definition.
+
+We would like to solicit feedback and encourage discussion around the
+merits and weaknesses of these approaches. This question is at the core
+of defining a good API and we'd like to get it right.
+
+
+Input and Output Transfer functions
+-----------------------------------
+
+We define an input transfer function on drm_plane to describe the
+transform from framebuffer to blending space.
+
+We define an output transfer function on drm_crtc to describe the
+transform from blending space to display space.
+
+The transfer function can be a pre-defined function, such as PQ EOTF, or
+a custom LUT. A driver will be able to specify support for specific
+transfer functions, including custom ones.
+
+Defining the transfer function in this way allows us to support in on HW
+that uses ROMs to support these transforms, as well as on HW that use
+LUT definitions that are complex and don't map easily onto a standard LUT
+definition.
+
+We will not define per-plane LUTs in this patchset as the scope of our
+current work only deals with pre-defined transfer functions. This API has
+the flexibility to add custom 1D or 3D LUTs at a later date.
+
+In order to support the existing 1D de-gamma and gamma LUTs on the drm_crtc
+we will include a "custom 1D" enum value to indicate that the custom gamma and
+de-gamma 1D LUTs should be used.
+
+Possible transfer functions:
+
+.. flat-table::
+ :header-rows: 1
+
+ * - Transfer Function
+ - Description
+
+ * - Gamma 2.2
+ - a simple 2.2 gamma function
+
+ * - sRGB
+ - 2.4 gamma with small initial linear section
+
+ * - PQ 2084
+ - SMPTE ST 2084; used for HDR video and allows for up to 10,000 nit support
+
+ * - Linear
+ - Linear relationship between pixel value and luminance value
+
+ * - Custom 1D
+ - Custom 1D de-gamma and gamma LUTs; one LUT per color
+
+ * - Custom 3D
+ - Custom 3D LUT (to be defined)
+
+
+Describing SDR Luminance
+------------------------------
+
+Since many displays do no correctly advertise the HDR white level we
+propose to define the SDR white level in nits.
+
+We define a new drm_plane property to specify the white level of an SDR
+plane.
+
+
+Defining the color space
+------------------------
+
+We propose to add a new color space property to drm_plane to define a
+plane's color space.
+
+While some color space conversions can be performed with a simple color
+transformation matrix (CTM) others require a 3D LUT.
+
+
+Defining mastering color space and luminance
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+ToDo
+
+
+
+Pixel Formats
+~~~~~~~~~~~~~
+
+The pixel formats, such as ARGB8888, ARGB2101010, P010, or FP16 are
+unrelated to color space and EOTF definitions. HDR pixels can be formatted
+in different ways but in order to not lose precision HDR content requires
+at least 10 bpc precision. For this reason ARGB2101010, P010, and FP16 are
+the obvious candidates for HDR. ARGB2101010 and P010 have the advantage
+of requiring only half the bandwidth as FP16, while FP16 has the advantage
+of enough precision to operate in a linear space, i.e. without EOTF.
+
+
+Use Cases
+=========
+
+RGB10 HDR plane - composited HDR video & desktop
+------------------------------------------------
+
+A single, composited plane of HDR content. The use-case is a video player
+on a desktop with the compositor owning the composition of SDR and HDR
+content. The content shall be PQ BT.2020 formatted. The drm_connector's
+hdr_output_metadata shall be set.
+
+
+P010 HDR video plane + RGB8 SDR desktop plane
+---------------------------------------------
+A normal 8bpc desktop plane, with a P010 HDR video plane underlayed. The
+HDR plane shall be PQ BT.2020 formatted. The desktop plane shall specify
+an SDR boost value. The drm_connector's hdr_output_metadata shall be set.
+
+
+One XRGB8888 SDR Plane - HDR output
+-----------------------------------
+
+In order to support a smooth transition we recommend an OS that supports
+HDR output to provide the hdr_output_metadata on the drm_connector to
+configure the output for HDR, even when the content is only SDR. This will
+allow for a smooth transition between SDR-only and HDR content. In this
+use-case the SDR max luminance value should be provided on the drm_plane.
+
+In DCN we will de-PQ or de-Gamma all input in order to blend in linear
+space. For SDR content we will also apply any desired boost before
+blending. After blending we will then re-apply the PQ EOTF and do RGB
+to YCbCr conversion if needed.
+
+FP16 HDR linear planes
+----------------------
+
+These will require a transformation into the display's encoding (e.g. PQ)
+using the CRTC LUT. Current CRTC LUTs are lacking the precision in the
+dark areas to do the conversion without losing detail.
+
+One of the newly defined output transfer functions or a PWL or `multi-segmented
+LUT`_ can be used to facilitate the conversion to PQ, HLG, or another
+encoding supported by displays.
+
+.. _multi-segmented LUT: https://patchwork.freedesktop.org/series/90822/
+
+
+User Space
+==========
+
+Gnome & GStreamer
+-----------------
+
+See Jeremy Cline's `HDR in Linux\: Part 2`_.
+
+.. _HDR in Linux\: Part 2: https://www.jcline.org/blog/fedora/graphics/hdr/2021/06/28/hdr-in-linux-p2.html
+
+
+Wayland
+-------
+
+See `Wayland Color Management and HDR Design Goals`_.
+
+.. _Wayland Color Management and HDR Design Goals: https://gitlab.freedesktop.org/swick/wayland-protocols/-/blob/color/unstable/color-management/color.rst
+
+
+ChromeOS Ozone
+--------------
+
+ToDo
+
+
+HW support
+==========
+
+ToDo, describe pipeline on a couple different HW platforms
+
+
+Further Reading
+===============
+
+* https://gitlab.freedesktop.org/swick/wayland-protocols/-/blob/color/unstable/color-management/color.rst
+* http://downloads.bbc.co.uk/rd/pubs/whp/whp-pdf-files/WHP309.pdf
+* https://app.spectracal.com/Documents/White%20Papers/HDR_Demystified.pdf
+* https://www.jcline.org/blog/fedora/graphics/hdr/2021/05/07/hdr-in-linux-p1.html
+* https://www.jcline.org/blog/fedora/graphics/hdr/2021/06/28/hdr-in-linux-p2.html
+
+
diff --git a/Documentation/gpu/rfc/index.rst b/Documentation/gpu/rfc/index.rst
index 05670442ca1b..8d8430cfdde1 100644
--- a/Documentation/gpu/rfc/index.rst
+++ b/Documentation/gpu/rfc/index.rst
@@ -19,3 +19,4 @@ host such documentation:
.. toctree::
i915_gem_lmem.rst
+ hdr-wide-gamut.rst
--
2.32.0
More information about the dri-devel
mailing list