drm/i915/dmc: Clear HRR EVT_CTL/HTP to zero on ADL-S

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commit dc8aa0cb87 upstream.

On ADL-S the main DMC HRR event DMC_EVT_CTL/HTP are never
restored to their previous values during DC6 exit. This
angers assert_dmc_loaded(), and basically makes the HRR
handler unusable because we don't rewrite EVT_HTP when
enabling DMC events.

Let's just clear the HRR EVT_CTL/HTP to zero from the
beginnning so that the expected value matches the post-DC6
reality.

I suppose if we ever had actual use for HRR we'd have to both,
reject HRR+PSR, and reprogram EVT_HTP when enabling the event.
But for now we don't care about HRR so keeping both registers
zeroed is fine.

Cc: stable@vger.kernel.org
Tested-by: Petr Vorel <pvorel@suse.cz>
Fixes: 43175c92d4 ("drm/i915/dmc: Assert DMC is loaded harder")
Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/15153
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20251022100718.24803-2-ville.syrjala@linux.intel.com
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Tested-by: Imre Deak <imre.deak@intel.com>
(cherry picked from commit 4df3b340ff)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

This commit is contained in:

Ville Syrjälä 2025-10-22 13:07:16 +03:00 • committed by Greg Kroah-Hartman

parent 8ba827e09e

commit 2606dfd971

1 changed files with 54 additions and 1 deletions

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drivers/gpu/drm/i915/display/intel_dmc.c

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