[v1] Revert "drm/amd/display: Only restore backlight after amdgpu_dm_init or dm_resume"

[PATCH] Revert "drm/amd/display: Only restore backlight after amdgpu_dm_init or dm_resume"

Posted by Matthew Schwartz 2 months, 1 week ago

This fix regressed the original issue that commit d83c747a1225
("drm/amd/display: Fix brightness level not retained over reboot") solved,
so revert it until a different approach to solve the regression that
it caused with AMD_PRIVATE_COLOR is found.

Fixes: a490c8d77d50 ("drm/amd/display: Only restore backlight after amdgpu_dm_init or dm_resume")
Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4620
Signed-off-by: Matthew Schwartz <matthew.schwartz@linux.dev>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 12 ++++--------
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h |  7 -------
 2 files changed, 4 insertions(+), 15 deletions(-)

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 8e1622bf7a42..21281e684b84 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -2081,8 +2081,6 @@ static int amdgpu_dm_init(struct amdgpu_device *adev)
 
 	dc_hardware_init(adev->dm.dc);
 
-	adev->dm.restore_backlight = true;
-
 	adev->dm.hpd_rx_offload_wq = hpd_rx_irq_create_workqueue(adev);
 	if (!adev->dm.hpd_rx_offload_wq) {
 		drm_err(adev_to_drm(adev), "failed to create hpd rx offload workqueue.\n");
@@ -3438,7 +3436,6 @@ static int dm_resume(struct amdgpu_ip_block *ip_block)
 		dc_set_power_state(dm->dc, DC_ACPI_CM_POWER_STATE_D0);
 
 		dc_resume(dm->dc);
-		adev->dm.restore_backlight = true;
 
 		amdgpu_dm_irq_resume_early(adev);
 
@@ -9965,6 +9962,7 @@ static void amdgpu_dm_commit_streams(struct drm_atomic_state *state,
 	bool mode_set_reset_required = false;
 	u32 i;
 	struct dc_commit_streams_params params = {dc_state->streams, dc_state->stream_count};
+	bool set_backlight_level = false;
 
 	/* Disable writeback */
 	for_each_old_connector_in_state(state, connector, old_con_state, i) {
@@ -10084,6 +10082,7 @@ static void amdgpu_dm_commit_streams(struct drm_atomic_state *state,
 			acrtc->hw_mode = new_crtc_state->mode;
 			crtc->hwmode = new_crtc_state->mode;
 			mode_set_reset_required = true;
+			set_backlight_level = true;
 		} else if (modereset_required(new_crtc_state)) {
 			drm_dbg_atomic(dev,
 				       "Atomic commit: RESET. crtc id %d:[%p]\n",
@@ -10140,16 +10139,13 @@ static void amdgpu_dm_commit_streams(struct drm_atomic_state *state,
 	 * to fix a flicker issue.
 	 * It will cause the dm->actual_brightness is not the current panel brightness
 	 * level. (the dm->brightness is the correct panel level)
-	 * So we set the backlight level with dm->brightness value after initial
-	 * set mode. Use restore_backlight flag to avoid setting backlight level
-	 * for every subsequent mode set.
+	 * So we set the backlight level with dm->brightness value after set mode
 	 */
-	if (dm->restore_backlight) {
+	if (set_backlight_level) {
 		for (i = 0; i < dm->num_of_edps; i++) {
 			if (dm->backlight_dev[i])
 				amdgpu_dm_backlight_set_level(dm, i, dm->brightness[i]);
 		}
-		dm->restore_backlight = false;
 	}
 }
 
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
index 009f206226f0..db75e991ac7b 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
@@ -630,13 +630,6 @@ struct amdgpu_display_manager {
 	 */
 	u32 actual_brightness[AMDGPU_DM_MAX_NUM_EDP];
 
-	/**
-	 * @restore_backlight:
-	 *
-	 * Flag to indicate whether to restore backlight after modeset.
-	 */
-	bool restore_backlight;
-
 	/**
 	 * @aux_hpd_discon_quirk:
 	 *
-- 
2.51.0

Re: [PATCH] Revert "drm/amd/display: Only restore backlight after amdgpu_dm_init or dm_resume"

Posted by Greg KH 2 months, 1 week ago

On Thu, Oct 09, 2025 at 11:23:01AM +0200, Matthew Schwartz wrote:
> This fix regressed the original issue that commit d83c747a1225
> ("drm/amd/display: Fix brightness level not retained over reboot") solved,
> so revert it until a different approach to solve the regression that
> it caused with AMD_PRIVATE_COLOR is found.
> 
> Fixes: a490c8d77d50 ("drm/amd/display: Only restore backlight after amdgpu_dm_init or dm_resume")
> Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4620
> Signed-off-by: Matthew Schwartz <matthew.schwartz@linux.dev>
> ---
>  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 12 ++++--------
>  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h |  7 -------
>  2 files changed, 4 insertions(+), 15 deletions(-)

<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree.  Please read:
    https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.

</formletter>

Re: [PATCH] Revert "drm/amd/display: Only restore backlight after amdgpu_dm_init or dm_resume"

Posted by Matthew Schwartz 2 months, 1 week ago

> 
> On Oct 9, 2025, at 11:51 AM, Greg KH <gregkh@linuxfoundation.org> wrote:
> 
> On Thu, Oct 09, 2025 at 11:23:01AM +0200, Matthew Schwartz wrote:
>> This fix regressed the original issue that commit d83c747a1225
>> ("drm/amd/display: Fix brightness level not retained over reboot") solved,
>> so revert it until a different approach to solve the regression that
>> it caused with AMD_PRIVATE_COLOR is found.
>> 
>> Fixes: a490c8d77d50 ("drm/amd/display: Only restore backlight after amdgpu_dm_init or dm_resume")
>> Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4620
>> Signed-off-by: Matthew Schwartz <matthew.schwartz@linux.dev>
>> ---
>> drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 12 ++++--------
>> drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h |  7 -------
>> 2 files changed, 4 insertions(+), 15 deletions(-)
> 
> <formletter>
> 
> This is not the correct way to submit patches for inclusion in the
> stable kernel tree.  Please read:
>    https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
> for how to do this properly.

Apologies, I was a bit confused by:

If a regression made it into a proper mainline release during the past twelve months, ensure to tag the fix with “Cc: stable@vger.kernel.org”

in the regressions page, but I see now the way I did it via email cc was incorrect.

Should I resend with that fixed?

> 
> </formletter>

Re: [PATCH] Revert "drm/amd/display: Only restore backlight after amdgpu_dm_init or dm_resume"

Posted by Greg KH 2 months, 1 week ago

On Thu, Oct 09, 2025 at 12:00:29PM +0200, Matthew Schwartz wrote:
> 
> > 
> > On Oct 9, 2025, at 11:51 AM, Greg KH <gregkh@linuxfoundation.org> wrote:
> > 
> > On Thu, Oct 09, 2025 at 11:23:01AM +0200, Matthew Schwartz wrote:
> >> This fix regressed the original issue that commit d83c747a1225
> >> ("drm/amd/display: Fix brightness level not retained over reboot") solved,
> >> so revert it until a different approach to solve the regression that
> >> it caused with AMD_PRIVATE_COLOR is found.
> >> 
> >> Fixes: a490c8d77d50 ("drm/amd/display: Only restore backlight after amdgpu_dm_init or dm_resume")
> >> Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4620
> >> Signed-off-by: Matthew Schwartz <matthew.schwartz@linux.dev>
> >> ---
> >> drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 12 ++++--------
> >> drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h |  7 -------
> >> 2 files changed, 4 insertions(+), 15 deletions(-)
> > 
> > <formletter>
> > 
> > This is not the correct way to submit patches for inclusion in the
> > stable kernel tree.  Please read:
> >    https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
> > for how to do this properly.
> 
> Apologies, I was a bit confused by:
> 
> If a regression made it into a proper mainline release during the past twelve months, ensure to tag the fix with “Cc: stable@vger.kernel.org”
> 
> in the regressions page, but I see now the way I did it via email cc was incorrect.
> 
> Should I resend with that fixed?

Please do.

thanks!

greg k-h