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<p style="margin-top:0;margin-bottom:0">Series is:</p>
<p style="margin-top:0;margin-bottom:0"><span>Reviewed-by: David Francis <david.francis@amd.com></span><br>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> amd-gfx <amd-gfx-bounces@lists.freedesktop.org> on behalf of Nicholas Kazlauskas <nicholas.kazlauskas@amd.com><br>
<b>Sent:</b> August 2, 2019 11:11:50 AM<br>
<b>To:</b> amd-gfx@lists.freedesktop.org <amd-gfx@lists.freedesktop.org><br>
<b>Cc:</b> Li, Sun peng (Leo) <Sunpeng.Li@amd.com>; Francis, David <David.Francis@amd.com>; Lakha, Bhawanpreet <Bhawanpreet.Lakha@amd.com>; Kazlauskas, Nicholas <Nicholas.Kazlauskas@amd.com><br>
<b>Subject:</b> [PATCH 2/2] drm/amd/display: Block immediate flips for non-fast updates</font>
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<div class="BodyFragment"><font size="2"><span style="font-size:11pt;">
<div class="PlainText">[Why]<br>
Underflow can occur in the case where we change buffer pitch, DCC state,<br>
rotation or mirroring for a plane while also performing an immediate<br>
flip. It can also generate a p-state warning stack trace on DCN1 which<br>
is typically observed during the cursor handler pipe locking because of<br>
how frequent cursor updates can occur.<br>
<br>
[How]<br>
Store the update type on each CRTC - every plane will have access to<br>
the CRTC state if it's flipping. If the update type is not<br>
UPDATE_TYPE_FAST then the immediate flip should be disallowed.<br>
<br>
No changes to the target vblank sequencing need to be done, we just<br>
need to ensure that the surface registers do a double buffered update.<br>
<br>
Cc: David Francis <david.francis@amd.com><br>
Cc: Bhawanpreet Lakha <bhawanpreet.lakha@amd.com><br>
Cc: Leo Li <sunpeng.li@amd.com><br>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com><br>
---<br>
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c    | 16 +++++++++++++++-<br>
 .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h    |  1 +<br>
 2 files changed, 16 insertions(+), 1 deletion(-)<br>
<br>
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c<br>
index ffb3c7247ac6..e941d0d3794b 100644<br>
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c<br>
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c<br>
@@ -5690,8 +5690,14 @@ static void amdgpu_dm_commit_planes(struct drm_atomic_state *state,<br>
                 bundle->surface_updates[planes_count].plane_info =<br>
                         &bundle->plane_infos[planes_count];<br>
 <br>
+               /*<br>
+                * Only allow immediate flips for fast updates that don't<br>
+                * change FB pitch, DCC state, rotation or mirroing.<br>
+                */<br>
                 bundle->flip_addrs[planes_count].flip_immediate =<br>
-                               (crtc->state->pageflip_flags & DRM_MODE_PAGE_FLIP_ASYNC) != 0;<br>
+                       (crtc->state->pageflip_flags &<br>
+                        DRM_MODE_PAGE_FLIP_ASYNC) != 0 &&<br>
+                       acrtc_state->update_type == UPDATE_TYPE_FAST;<br>
 <br>
                 timestamp_ns = ktime_get_ns();<br>
                 bundle->flip_addrs[planes_count].flip_timestamp_in_us = div_u64(timestamp_ns, 1000);<br>
@@ -7311,6 +7317,14 @@ static int amdgpu_dm_atomic_check(struct drm_device *dev,<br>
                 state->async_update = !drm_atomic_helper_async_check(dev, state);<br>
         }<br>
 <br>
+       /* Store the overall update type for use later in atomic check. */<br>
+       for_each_new_crtc_in_state (state, crtc, new_crtc_state, i) {<br>
+               struct dm_crtc_state *dm_new_crtc_state =<br>
+                       to_dm_crtc_state(new_crtc_state);<br>
+<br>
+               dm_new_crtc_state->update_type = (int)overall_update_type;<br>
+       }<br>
+<br>
         /* Must be success */<br>
         WARN_ON(ret);<br>
         return ret;<br>
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h<br>
index da48a857949f..cbd6608f58e6 100644<br>
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h<br>
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h<br>
@@ -307,6 +307,7 @@ struct dm_crtc_state {<br>
         bool cm_has_degamma;<br>
         bool cm_is_degamma_srgb;<br>
 <br>
+       int update_type;<br>
         int active_planes;<br>
         bool interrupts_enabled;<br>
 <br>
-- <br>
2.17.1<br>
<br>
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