Patch "drm/i915: Don't do the WM0->WM1 copy w/a if WM1 is already enabled" has been added to the 6.1-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    drm/i915: Don't do the WM0->WM1 copy w/a if WM1 is already enabled

to the 6.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-i915-don-t-do-the-wm0-wm1-copy-w-a-if-wm1-is-alr.patch
and it can be found in the queue-6.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit a4622a89d4ea4831d2963e68c870a889cd08094a
Author: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Date:   Tue Jan 31 02:21:24 2023 +0200

    drm/i915: Don't do the WM0->WM1 copy w/a if WM1 is already enabled
    
    [ Upstream commit 90d5e8301ac24550be80d193aa5582cab56c29fc ]
    
    Due to a workaround we have to make sure the WM1 watermarks block/lines
    values are sensible even when WM1 is disabled. To that end we copy those
    values from WM0.
    
    However since we now keep each wm level enabled on a per-plane basis
    it doesn't seem necessary to do that copy when we already have an
    enabled WM1 on the current plane. That is, we might be in a situation
    where another plane can only do WM0 (and thus needs the copy) but
    the current plane's WM1 is still perfectly valid (ie. fits into the
    current DDB allocation).
    
    Skipping the copy could avoid reprogramming the plane's registers
    needlessly in some cases.
    
    Fixes: a301cb0fca2d ("drm/i915: Keep plane watermarks enabled more aggressively")
    Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
    Link: https://patchwork.freedesktop.org/patch/msgid/20230131002127.29305-1-ville.syrjala@xxxxxxxxxxxxxxx
    Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@xxxxxxxxx>
    (cherry picked from commit c580c2d27ac8754cc6f01da1d715b7272f5f9cbb)
    Signed-off-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/gpu/drm/i915/display/skl_watermark.c b/drivers/gpu/drm/i915/display/skl_watermark.c
index 18178b01375e4..a7adf02476f6a 100644
--- a/drivers/gpu/drm/i915/display/skl_watermark.c
+++ b/drivers/gpu/drm/i915/display/skl_watermark.c
@@ -1587,7 +1587,8 @@ skl_crtc_allocate_plane_ddb(struct intel_atomic_state *state,
 				skl_check_wm_level(&wm->wm[level], ddb);
 
 			if (icl_need_wm1_wa(i915, plane_id) &&
-			    level == 1 && wm->wm[0].enable) {
+			    level == 1 && !wm->wm[level].enable &&
+			    wm->wm[0].enable) {
 				wm->wm[level].blocks = wm->wm[0].blocks;
 				wm->wm[level].lines = wm->wm[0].lines;
 				wm->wm[level].ignore_lines = wm->wm[0].ignore_lines;