drm: Implement state readout support

[PATCH 04/29] drm/atomic_helper: Skip over NULL private_obj pointers

Posted by Maxime Ripard 1 month ago

Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
 drivers/gpu/drm/drm_atomic.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index b356d26faad4acaa25c1fe6f9bd5043b6364ce87..9b198610791d19c7fd276ca59264a961d21caf43 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -295,10 +295,13 @@ void drm_atomic_state_default_clear(struct drm_atomic_state *state)
 	}
 
 	for (i = 0; i < state->num_private_objs; i++) {
 		struct drm_private_obj *obj = state->private_objs[i].ptr;
 
+		if (!obj)
+			continue;
+
 		obj->funcs->atomic_destroy_state(obj,
 						 state->private_objs[i].state);
 		state->private_objs[i].ptr = NULL;
 		state->private_objs[i].state = NULL;
 		state->private_objs[i].old_state = NULL;

-- 
2.50.1

Re: [PATCH 04/29] drm/atomic_helper: Skip over NULL private_obj pointers

Posted by Thomas Zimmermann 1 month ago


Am 02.09.25 um 10:32 schrieb Maxime Ripard:
> Signed-off-by: Maxime Ripard <mripard@kernel.org>

Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>

However, can this happen? Private state objects without state data?

Best regards
Thomas

> ---
>   drivers/gpu/drm/drm_atomic.c | 3 +++
>   1 file changed, 3 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
> index b356d26faad4acaa25c1fe6f9bd5043b6364ce87..9b198610791d19c7fd276ca59264a961d21caf43 100644
> --- a/drivers/gpu/drm/drm_atomic.c
> +++ b/drivers/gpu/drm/drm_atomic.c
> @@ -295,10 +295,13 @@ void drm_atomic_state_default_clear(struct drm_atomic_state *state)
>   	}
>   
>   	for (i = 0; i < state->num_private_objs; i++) {
>   		struct drm_private_obj *obj = state->private_objs[i].ptr;
>   
> +		if (!obj)
> +			continue;
> +
>   		obj->funcs->atomic_destroy_state(obj,
>   						 state->private_objs[i].state);
>   		state->private_objs[i].ptr = NULL;
>   		state->private_objs[i].state = NULL;
>   		state->private_objs[i].old_state = NULL;
>

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)

Re: [PATCH 04/29] drm/atomic_helper: Skip over NULL private_obj pointers

Posted by Maxime Ripard 1 week, 3 days ago

On Tue, Sep 02, 2025 at 03:13:30PM +0200, Thomas Zimmermann wrote:
> Am 02.09.25 um 10:32 schrieb Maxime Ripard:
> > Signed-off-by: Maxime Ripard <mripard@kernel.org>
> 
> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
> 
> However, can this happen? Private state objects without state data?

Yeah, sorry, I forgot to add a commit log to that one. I'll add one.

Maxime

Re: [PATCH 04/29] drm/atomic_helper: Skip over NULL private_obj pointers

Posted by Laurent Pinchart 1 month ago

On Tue, Sep 02, 2025 at 03:13:30PM +0200, Thomas Zimmermann wrote:
> Am 02.09.25 um 10:32 schrieb Maxime Ripard:
> > Signed-off-by: Maxime Ripard <mripard@kernel.org>
> 
> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
> 
> However, can this happen? Private state objects without state data?

I was going to ask the same. The commit message should explain why.

> > ---
> >   drivers/gpu/drm/drm_atomic.c | 3 +++
> >   1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
> > index b356d26faad4acaa25c1fe6f9bd5043b6364ce87..9b198610791d19c7fd276ca59264a961d21caf43 100644
> > --- a/drivers/gpu/drm/drm_atomic.c
> > +++ b/drivers/gpu/drm/drm_atomic.c
> > @@ -295,10 +295,13 @@ void drm_atomic_state_default_clear(struct drm_atomic_state *state)
> >   	}
> >   
> >   	for (i = 0; i < state->num_private_objs; i++) {
> >   		struct drm_private_obj *obj = state->private_objs[i].ptr;
> >   
> > +		if (!obj)
> > +			continue;
> > +
> >   		obj->funcs->atomic_destroy_state(obj,
> >   						 state->private_objs[i].state);
> >   		state->private_objs[i].ptr = NULL;
> >   		state->private_objs[i].state = NULL;
> >   		state->private_objs[i].old_state = NULL;

-- 
Regards,

Laurent Pinchart