drm/atomic-helper: Add a note in drm_atomic_helper_reset_crtc() kernel-doc

[PATCH] drm/atomic-helper: Add a note in drm_atomic_helper_reset_crtc() kernel-doc

Posted by Herve Codina 9 months, 4 weeks ago

As suggested in [0], add a note indicating that
drm_atomic_helper_reset_crtc() can be a no-op in some cases.

[0]:https://lore.kernel.org/all/Z7XfnPGDYspwG42y@phenom.ffwll.local/

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
---
 This patch applies on top of the following commit available in drm-misc
   ab83b7f6a0c1 ("drm/atomic-helper: Introduce drm_atomic_helper_reset_crtc()")

 drivers/gpu/drm/drm_atomic_helper.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 0a636c398578..1f93b0a855de 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -3371,6 +3371,10 @@ EXPORT_SYMBOL(drm_atomic_helper_disable_all);
  * This implies a reset of all active components available between the CRTC and
  * connectors.
  *
+ * NOTE: This relies on resetting &drm_crtc_state.connectors_changed.
+ * For drivers which optimize out unnecessary modesets this will result in
+ * a no-op commit, achieving nothing.
+ *
  * Returns:
  * 0 on success or a negative error code on failure.
  */
-- 
2.48.1

Re: [PATCH] drm/atomic-helper: Add a note in drm_atomic_helper_reset_crtc() kernel-doc

Posted by Simona Vetter 9 months, 4 weeks ago

On Thu, Feb 20, 2025 at 03:04:06PM +0100, Herve Codina wrote:
> As suggested in [0], add a note indicating that
> drm_atomic_helper_reset_crtc() can be a no-op in some cases.
> 
> [0]:https://lore.kernel.org/all/Z7XfnPGDYspwG42y@phenom.ffwll.local/
> 
> Signed-off-by: Herve Codina <herve.codina@bootlin.com>

Reviewed-by: Simona Vetter <simona.vetter@ffwll.ch>

I'm assuming you or someone else at bootling has commit rights? Otherwise
I guess on Maxime to get that sorted.
-Sima

> ---
>  This patch applies on top of the following commit available in drm-misc
>    ab83b7f6a0c1 ("drm/atomic-helper: Introduce drm_atomic_helper_reset_crtc()")
> 
>  drivers/gpu/drm/drm_atomic_helper.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
> index 0a636c398578..1f93b0a855de 100644
> --- a/drivers/gpu/drm/drm_atomic_helper.c
> +++ b/drivers/gpu/drm/drm_atomic_helper.c
> @@ -3371,6 +3371,10 @@ EXPORT_SYMBOL(drm_atomic_helper_disable_all);
>   * This implies a reset of all active components available between the CRTC and
>   * connectors.
>   *
> + * NOTE: This relies on resetting &drm_crtc_state.connectors_changed.
> + * For drivers which optimize out unnecessary modesets this will result in
> + * a no-op commit, achieving nothing.
> + *
>   * Returns:
>   * 0 on success or a negative error code on failure.
>   */
> -- 
> 2.48.1
> 

-- 
Simona Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

Re: [PATCH] drm/atomic-helper: Add a note in drm_atomic_helper_reset_crtc() kernel-doc

Posted by Louis Chauvet 9 months, 4 weeks ago


Le 21/02/2025 à 10:51, Simona Vetter a écrit :
> On Thu, Feb 20, 2025 at 03:04:06PM +0100, Herve Codina wrote:
>> As suggested in [0], add a note indicating that
>> drm_atomic_helper_reset_crtc() can be a no-op in some cases.
>>
>> [0]:https://lore.kernel.org/all/Z7XfnPGDYspwG42y@phenom.ffwll.local/
>>
>> Signed-off-by: Herve Codina <herve.codina@bootlin.com>
> 
> Reviewed-by: Simona Vetter <simona.vetter@ffwll.ch>
> 
> I'm assuming you or someone else at bootling has commit rights?

Yes, I have!

> Otherwise
> I guess on Maxime to get that sorted.
> -Sima

Applied on drm-misc-next, thanks!

Louis Chauvet

>> ---
>>   This patch applies on top of the following commit available in drm-misc
>>     ab83b7f6a0c1 ("drm/atomic-helper: Introduce drm_atomic_helper_reset_crtc()")
>>
>>   drivers/gpu/drm/drm_atomic_helper.c | 4 ++++
>>   1 file changed, 4 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
>> index 0a636c398578..1f93b0a855de 100644
>> --- a/drivers/gpu/drm/drm_atomic_helper.c
>> +++ b/drivers/gpu/drm/drm_atomic_helper.c
>> @@ -3371,6 +3371,10 @@ EXPORT_SYMBOL(drm_atomic_helper_disable_all);
>>    * This implies a reset of all active components available between the CRTC and
>>    * connectors.
>>    *
>> + * NOTE: This relies on resetting &drm_crtc_state.connectors_changed.
>> + * For drivers which optimize out unnecessary modesets this will result in
>> + * a no-op commit, achieving nothing.
>> + *
>>    * Returns:
>>    * 0 on success or a negative error code on failure.
>>    */
>> -- 
>> 2.48.1
>>
> 

-- 
Louis Chauvet, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com