6.17-stable review patch. If anyone has any objections, please let me know.
------------------
From: Matthew Schwartz matthew.schwartz@linux.dev
commit 382bd6a792836875da555fe9a2b51222b813fed1 upstream.
Before commit 33056a97ae5e ("drm/amd/display: Remove double checks for `debug.enable_mem_low_power.bits.cm`"), dpp3_program_blnd_lut(NULL) checked the low-power debug flag before calling dpp3_power_on_blnd_lut(false).
After commit 33056a97ae5e ("drm/amd/display: Remove double checks for `debug.enable_mem_low_power.bits.cm`"), dpp3_program_blnd_lut(NULL) unconditionally calls dpp3_power_on_blnd_lut(false). The BLNDGAM power helper writes BLNDGAM_MEM_PWR_FORCE when CM low-power is disabled, causing immediate SRAM power toggles instead of deferring at vupdate. This can disrupt atomic color/LUT sequencing during transitions between direct scanout and composition within gamescope's DRM backend on Steam Deck OLED.
To fix this, leave the BLNDGAM power state unchanged when low-power is disabled, matching dpp3_power_on_hdr3dlut and dpp3_power_on_shaper.
Fixes: 33056a97ae5e ("drm/amd/display: Remove double checks for `debug.enable_mem_low_power.bits.cm`") Signed-off-by: Matthew Schwartz matthew.schwartz@linux.dev Reviewed-by: Harry Wentland harry.wentland@amd.com Reviewed-by: Mario Limonciello mario.limonciello@amd.com Signed-off-by: Mario Limonciello mario.limonciello@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com (cherry picked from commit 13ff4f63fcddfc84ec8632f1443936b00aa26725) Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/amd/display/dc/dpp/dcn30/dcn30_dpp.c | 3 --- 1 file changed, 3 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/dpp/dcn30/dcn30_dpp.c b/drivers/gpu/drm/amd/display/dc/dpp/dcn30/dcn30_dpp.c index 09be2a90cc79..4f569cd8a5d6 100644 --- a/drivers/gpu/drm/amd/display/dc/dpp/dcn30/dcn30_dpp.c +++ b/drivers/gpu/drm/amd/display/dc/dpp/dcn30/dcn30_dpp.c @@ -578,9 +578,6 @@ static void dpp3_power_on_blnd_lut( dpp_base->ctx->dc->optimized_required = true; dpp_base->deferred_reg_writes.bits.disable_blnd_lut = true; } - } else { - REG_SET(CM_MEM_PWR_CTRL, 0, - BLNDGAM_MEM_PWR_FORCE, power_on == true ? 0 : 1); } }