From: Leo Li sunpeng.li@amd.com

Backlight updates require aux and/or register access. Therefore, driver needs to disallow IPS beforehand.

So, acquire the dc lock before calling into dc to update backlight - we should be doing this regardless of IPS. Then, while the lock is held, disallow IPS before calling into dc, then allow IPS afterwards (if it was previously allowed).

Cc: stable@vger.kernel.org # 6.10+ Reviewed-by: Aurabindo Pillai aurabindo.pillai@amd.com Reviewed-by: Roman Li roman.li@amd.com Signed-off-by: Leo Li sunpeng.li@amd.com Signed-off-by: Hamza Mahfooz hamza.mahfooz@amd.com --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index 351f8b0fe7a1..fa26b8d59f23 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -4512,7 +4512,7 @@ static void amdgpu_dm_backlight_set_level(struct amdgpu_display_manager *dm, struct amdgpu_dm_backlight_caps caps; struct dc_link *link; u32 brightness; - bool rc; + bool rc, reallow_idle = false;

amdgpu_dm_update_backlight_caps(dm, bl_idx); caps = dm->backlight_caps[bl_idx]; @@ -4525,6 +4525,12 @@ static void amdgpu_dm_backlight_set_level(struct amdgpu_display_manager *dm, link = (struct dc_link *)dm->backlight_link[bl_idx];

/* Change brightness based on AUX property */ + mutex_lock(&dm->dc_lock); + if (dm->dc->caps.ips_support && dm->dc->ctx->dmub_srv->idle_allowed) { + dc_allow_idle_optimizations(dm->dc, false); + reallow_idle = true; + } + if (caps.aux_support) { rc = dc_link_set_backlight_level_nits(link, true, brightness, AUX_BL_DEFAULT_TRANSITION_TIME_MS); @@ -4536,6 +4542,11 @@ static void amdgpu_dm_backlight_set_level(struct amdgpu_display_manager *dm, DRM_DEBUG("DM: Failed to update backlight on eDP[%d]\n", bl_idx); }

+ if (dm->dc->caps.ips_support && reallow_idle) + dc_allow_idle_optimizations(dm->dc, true); + + mutex_unlock(&dm->dc_lock); + if (rc) dm->actual_brightness[bl_idx] = user_brightness; }