[Intel-gfx] [PATCH 00/23] Color Management for DRM
Sharma, Shashank
shashank.sharma at intel.com
Wed Sep 23 01:38:02 PDT 2015
Regards
Shashank
On 9/22/2015 6:57 PM, Daniel Vetter wrote:
> On Wed, Sep 16, 2015 at 11:06:57PM +0530, Shashank Sharma wrote:
>> This patch set adds Color Manager implementation in DRM layer. Color Manager
>> is an extension in DRM framework to support color correction/enhancement.
>>
>> Various Hardware platforms can support several color correction capabilities.
>> Color Manager provides abstraction of these capabilities and allows a user
>> space UI agent to correct/enhance the display using the DRM property interface.
>>
>> How is this going to work?
>> ==========================
>> 1. This patch series adds a few new properties in DRM framework. These properties are:
>> a. color_capabilities property (type blob)
>> b. Color Transformation Matrix property for corrections like CSC (called CTM, type blob)
>> c. Palette correction properties for corrections like gamma fixup (called palette_correction, type blob)
>> 2. Also, this patch series adds few structures to indicate specifications of a property like size, no_of_samples for correction etc.
>> 3. These properties are present in mode_config.
>> 4. When the platform's display driver loads, it fills up the values of color_capabilities property using the standard structures (added in step 2).
>> For example, Intel's I915 driver adds following color correction capabilities:
>> a. gamma correction capability as palette correction property, with 257 correction coefficients and a max/min value
>> b. csc correction capability as CTM correction property, with 3x3 transformation matrix values and max/min values
>> 5. Now when userspace comes up, it queries the platform's color capabilities by doing a get_property() on color_capabilities DRM property
>> 6. Reading the blob, the userspace understands the color capabilities of the platform.
>> For example, userspace will understand it can support:
>> a. palette_correction with 257 coefficients
>> b. CSC correction with 3x3 = 9 values
>> 7. To set color correction values, userspace:
>> a. creates a blob using the create_blob_ioctl in standard palette_correction structure format, with the correction values
>> b. calls the set_property_ioctl with the blob_id as value for the property
>> 8. Driver refers to the blob, gets the correction values and applies the correction in HW.
>> 9. To get currently applied color correction values, userspace:
>> a. calls a get_property_ioctl on that color property
>> b. gets the blob_id for the currently applied correction from DRM infrastructure
>> c. gets the blob using get_blob_ioctl and hence the currently applied values
>>
>> That's all! :)
>>
>> About the patch series:
>> =======================
>> The patch series first adds the color management support in DRM layer.
>> Then it adds the color management framework in I915 layer.
>> After that, it implements platform specific core color correction functios.
>>
>> Intel color manager registers color correction with DRM color manager in this way:
>> - CSC transformation is registered as CTM DRM property
>> - Gamma correction is registered as palette_after_ctm DRM property
>> - Degamma correction is registered as palette_before_ctm DRM property
>>
>> Our thanks to all the reviewers who have given valuable comments in terms
>> of design and implementation to our previous sets of patches. Special mention
>> of thanks should go to Matt Roper for all his inputs/suggestions in implementation
>> of this module, using DRM atomic CRTC commit path.
>>
>> V2: Worked on review comments from Matt, Jim, Thierry, Rob.
>> V3: Worked on review comments from Matt, Jim, Rob:
>> - Jim, Rob:
>> ========
>> Re-arranged the whole patch series in the sequence of features, currently:
>> First 5 patches add color management support in DRM layer
>> Next 7 patches add Intel color management framework in I915 driver
>> Next 5 patches add color correction for CHV (gamma, degamma and CSC)
>> Next 2 patches enable color management, by attaching the properties to CRTC(Matt)
>> Next 4 patches add color correction for BDW (gamma, degamma)
>> - Matt:
>> =====
>> Patch 3: Added refernce/unreference for blob
>> Patch 7: return -EINVAL and added debug message
>> Patch 8: check for valid blob, from create blob
>> moved call to intel_crtc_attach_color_prop in the end of full implementation (CHV)
>> Patch 9: DRM_ERROR->DRM_DEBUG for NULL blob case
>> Patch 13: Added static for internal functions
>> Patch 20-24: renamed gen9_* functions to bdw_*
>> Added new variables in device_info structure num_samples_after_ctm and num_samples_before_ctm
>> Added new function in patch 8 to load capabilities based on device_info across all platforms
>
> Ok I finally got around to look at the kernel/userspace and drm core parts
> in detail. There's a few minor bits to polish but nothing serious I think,
> looks good overall (but I didn't really look at the i915 side).
>
> One thing though is the kerneldoc part. You have some great detailed
> comments in the structs about how this is all supposed to be used, but
> afaict they're not pulled into the kerneldoc anywhere. Also we don't have
> an overview section, but if you add the drm_crtc_attach_cc_properties
> function like I suggested we could add that there (with links to all the
> various structures).
>
Now, after the explanation in the corresponding patch, do you still find
a need for the function ?
> There's also the giant drm props table but that one is a mess. My
> suggestion would be to start a new DOC: section just for color correction,
> with an integrated markdown table. Then add that as a subsection to KMS
> property documentation. That way we'll have solid docs for this KMS
> extension (something we should have for all the other stuff like rotation
> or zpos too).
>
Yes, sure, I will do this.
> Thanks, Daniel
>
>>
>> Shashank Sharma (23):
>> drm: Create Color Management DRM properties
>> drm: Add structure for querying palette color capabilities
>> drm: Add color correction blobs in CRTC state
>> drm: Add drm structures for palette color property
>> drm: Add structure to set/get a CTM color property
>> drm/i915: Add atomic set property interface for CRTC
>> drm/i915: Add atomic get property interface for CRTC
>> drm/i915: Create color management files
>> drm/i915: Register pipe color capabilities
>> drm/i915: Add gamma correction handlers
>> drm/i915: Add pipe deGamma correction handlers
>> drm/i915: Add pipe CSC correction handlers
>> drm/i915: CHV: Load gamma color correction values
>> drm/i915: CHV: Pipe level Gamma correction
>> drm/i915: CHV: Load degamma color correction values
>> drm/i915: CHV: Pipe level degamma correction
>> drm/i915: CHV: Pipe level CSC correction
>> drm/i915: Commit color changes to CRTC
>> drm/i915: Attach color properties to CRTC
>> drm/i915: BDW: Load gamma correction values
>> drm/i915: BDW: Pipe level Gamma correction
>> drm/i915: BDW: Load degamma correction values
>> drm/i915: BDW: Pipe level degamma correction
>>
>> drivers/gpu/drm/drm_atomic_helper.c | 12 +
>> drivers/gpu/drm/drm_crtc.c | 26 +
>> drivers/gpu/drm/i915/Makefile | 3 +-
>> drivers/gpu/drm/i915/i915_drv.c | 17 +
>> drivers/gpu/drm/i915/i915_drv.h | 2 +
>> drivers/gpu/drm/i915/i915_reg.h | 41 +-
>> drivers/gpu/drm/i915/intel_atomic.c | 56 ++
>> drivers/gpu/drm/i915/intel_color_manager.c | 852 +++++++++++++++++++++++++++++
>> drivers/gpu/drm/i915/intel_color_manager.h | 99 ++++
>> drivers/gpu/drm/i915/intel_display.c | 6 +
>> drivers/gpu/drm/i915/intel_drv.h | 22 +
>> include/drm/drm_crtc.h | 11 +
>> include/uapi/drm/drm.h | 50 ++
>> 13 files changed, 1195 insertions(+), 2 deletions(-)
>> create mode 100644 drivers/gpu/drm/i915/intel_color_manager.c
>> create mode 100644 drivers/gpu/drm/i915/intel_color_manager.h
>>
>> --
>> 1.9.1
>>
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>
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