The function disable_outputs() and
drm_atomic_helper_commit_modeset_enables() tries to retrieve
helper_private from the target CRTC, for dereferencing some operations.
However, the current implementation does not check whether
helper_private is null and, if not, if it has a valid pointer to a dpms
and commit functions. This commit adds pointer validations before
trying to dereference the dpms and commit function.
Signed-off-by: Rodrigo Siqueira <[email protected]>
---
drivers/gpu/drm/drm_atomic_helper.c | 30 ++++++++++++++++-------------
1 file changed, 17 insertions(+), 13 deletions(-)
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 540a77a2ade9..fbeef7c461fc 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -1028,14 +1028,16 @@ disable_outputs(struct drm_device *dev, struct drm_atomic_state *old_state)
/* Right function depends upon target state. */
- if (new_crtc_state->enable && funcs->prepare)
- funcs->prepare(crtc);
- else if (funcs->atomic_disable)
- funcs->atomic_disable(crtc, old_crtc_state);
- else if (funcs->disable)
- funcs->disable(crtc);
- else
- funcs->dpms(crtc, DRM_MODE_DPMS_OFF);
+ if (funcs) {
+ if (new_crtc_state->enable && funcs->prepare)
+ funcs->prepare(crtc);
+ else if (funcs->atomic_disable)
+ funcs->atomic_disable(crtc, old_crtc_state);
+ else if (funcs->disable)
+ funcs->disable(crtc);
+ else if (funcs->dpms)
+ funcs->dpms(crtc, DRM_MODE_DPMS_OFF);
+ }
if (!(dev->irq_enabled && dev->num_crtcs))
continue;
@@ -1277,11 +1279,13 @@ void drm_atomic_helper_commit_modeset_enables(struct drm_device *dev,
if (new_crtc_state->enable) {
DRM_DEBUG_ATOMIC("enabling [CRTC:%d:%s]\n",
crtc->base.id, crtc->name);
-
- if (funcs->atomic_enable)
- funcs->atomic_enable(crtc, old_crtc_state);
- else
- funcs->commit(crtc);
+ if (funcs) {
+ if (funcs->atomic_enable)
+ funcs->atomic_enable(crtc,
+ old_crtc_state);
+ else if (funcs->atomic_enable)
+ funcs->commit(crtc);
+ }
}
}
--
2.21.0
Hi Rodrigo
On Mon, Mar 11, 2019 at 06:01:20PM -0300, Rodrigo Siqueira wrote:
> The function disable_outputs() and
> drm_atomic_helper_commit_modeset_enables() tries to retrieve
> helper_private from the target CRTC, for dereferencing some operations.
> However, the current implementation does not check whether
> helper_private is null and, if not, if it has a valid pointer to a dpms
> and commit functions. This commit adds pointer validations before
> trying to dereference the dpms and commit function.
>
> Signed-off-by: Rodrigo Siqueira <[email protected]>
> ---
> drivers/gpu/drm/drm_atomic_helper.c | 30 ++++++++++++++++-------------
> 1 file changed, 17 insertions(+), 13 deletions(-)
>
> @@ -1277,11 +1279,13 @@ void drm_atomic_helper_commit_modeset_enables(struct drm_device *dev,
> if (new_crtc_state->enable) {
> DRM_DEBUG_ATOMIC("enabling [CRTC:%d:%s]\n",
> crtc->base.id, crtc->name);
This DEBUG_ print is only relevant if the code actually
do something in the following.
So it seems more correct to fix the upper if () to:
> if (new_crtc_state->enable && funcs != NULL) {
> DRM_DEBUG_ATOMIC("enabling [CRTC:%d:%s]\n",
...
The you also loose one indent and the calls are nicer.
(If used "funcs != NULL", but this is a matter of taste).
Sam
Hi,
> - if (funcs->atomic_enable)
> - funcs->atomic_enable(crtc, old_crtc_state);
> - else
> - funcs->commit(crtc);
> + if (funcs) {
> + if (funcs->atomic_enable)
> + funcs->atomic_enable(crtc,
> + old_crtc_state);
> + else if (funcs->atomic_enable)
"if (funcs->commit)" I guess?
> + funcs->commit(crtc);
> + }
cheers,
Gerd
On Mon, Mar 11, 2019 at 06:01:20PM -0300, Rodrigo Siqueira wrote:
> The function disable_outputs() and
> drm_atomic_helper_commit_modeset_enables() tries to retrieve
> helper_private from the target CRTC, for dereferencing some operations.
> However, the current implementation does not check whether
> helper_private is null and, if not, if it has a valid pointer to a dpms
> and commit functions. This commit adds pointer validations before
> trying to dereference the dpms and commit function.
>
> Signed-off-by: Rodrigo Siqueira <[email protected]>
Please also adjust the kerneldoc for these functions. And I think the
patch subject can be improved, e.g. "Make ->atomic_enable/disable crtc
callbacks optional". Describe what you're trying to achieve in the
summary, not how you achieve it.
> ---
> drivers/gpu/drm/drm_atomic_helper.c | 30 ++++++++++++++++-------------
> 1 file changed, 17 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
> index 540a77a2ade9..fbeef7c461fc 100644
> --- a/drivers/gpu/drm/drm_atomic_helper.c
> +++ b/drivers/gpu/drm/drm_atomic_helper.c
> @@ -1028,14 +1028,16 @@ disable_outputs(struct drm_device *dev, struct drm_atomic_state *old_state)
>
>
> /* Right function depends upon target state. */
> - if (new_crtc_state->enable && funcs->prepare)
> - funcs->prepare(crtc);
> - else if (funcs->atomic_disable)
> - funcs->atomic_disable(crtc, old_crtc_state);
> - else if (funcs->disable)
> - funcs->disable(crtc);
> - else
> - funcs->dpms(crtc, DRM_MODE_DPMS_OFF);
> + if (funcs) {
I don't think making funcs optional is a good idea. If you have a crtc
with no functions implemented, it's not terribly useful.
Also making functions optional just here is not going to help if we still
require it everywhere else.
-Daniel
> + if (new_crtc_state->enable && funcs->prepare)
> + funcs->prepare(crtc);
> + else if (funcs->atomic_disable)
> + funcs->atomic_disable(crtc, old_crtc_state);
> + else if (funcs->disable)
> + funcs->disable(crtc);
> + else if (funcs->dpms)
> + funcs->dpms(crtc, DRM_MODE_DPMS_OFF);
> + }
>
> if (!(dev->irq_enabled && dev->num_crtcs))
> continue;
> @@ -1277,11 +1279,13 @@ void drm_atomic_helper_commit_modeset_enables(struct drm_device *dev,
> if (new_crtc_state->enable) {
> DRM_DEBUG_ATOMIC("enabling [CRTC:%d:%s]\n",
> crtc->base.id, crtc->name);
> -
> - if (funcs->atomic_enable)
> - funcs->atomic_enable(crtc, old_crtc_state);
> - else
> - funcs->commit(crtc);
> + if (funcs) {
> + if (funcs->atomic_enable)
> + funcs->atomic_enable(crtc,
> + old_crtc_state);
> + else if (funcs->atomic_enable)
> + funcs->commit(crtc);
> + }
> }
> }
>
> --
> 2.21.0
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
Hi,
First of all, thanks for the feedback.
I will fix all the problems pointed out in the review.
I just have two inline questions.
On 03/12, Daniel Vetter wrote:
> On Mon, Mar 11, 2019 at 06:01:20PM -0300, Rodrigo Siqueira wrote:
> > The function disable_outputs() and
> > drm_atomic_helper_commit_modeset_enables() tries to retrieve
> > helper_private from the target CRTC, for dereferencing some operations.
> > However, the current implementation does not check whether
> > helper_private is null and, if not, if it has a valid pointer to a dpms
> > and commit functions. This commit adds pointer validations before
> > trying to dereference the dpms and commit function.
> >
> > Signed-off-by: Rodrigo Siqueira <[email protected]>
>
> Please also adjust the kerneldoc for these functions. And I think the
> patch subject can be improved, e.g. "Make ->atomic_enable/disable crtc
> callbacks optional". Describe what you're trying to achieve in the
> summary, not how you achieve it.
Do I need to add information which says that both functions are
optional? I'm asking because the description related to the affected
functions and struct looks good for me [1,2,3].
1. Documentation for drm_crtc_helper_funcs:
https://dri.freedesktop.org/docs/drm/gpu/drm-kms-helpers.html?highlight=drm_crtc_helper_funcs#c.drm_crtc_helper_funcs
2. Documentation for drm_atomic_helper_commit_modeset_enables():
https://dri.freedesktop.org/docs/drm/gpu/drm-kms-helpers.html?highlight=drm_atomic_helper_commit_modeset_enables#c.drm_atomic_helper_commit_modeset_enables
3. Documentation for drm_atomic_helper_commit_modeset_disables():
https://dri.freedesktop.org/docs/drm/gpu/drm-kms-helpers.html?highlight=drm_atomic_helper_commit_modeset_disables#c.drm_atomic_helper_commit_modeset_disables
> > ---
> > drivers/gpu/drm/drm_atomic_helper.c | 30 ++++++++++++++++-------------
> > 1 file changed, 17 insertions(+), 13 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
> > index 540a77a2ade9..fbeef7c461fc 100644
> > --- a/drivers/gpu/drm/drm_atomic_helper.c
> > +++ b/drivers/gpu/drm/drm_atomic_helper.c
> > @@ -1028,14 +1028,16 @@ disable_outputs(struct drm_device *dev, struct drm_atomic_state *old_state)
> >
> >
> > /* Right function depends upon target state. */
> > - if (new_crtc_state->enable && funcs->prepare)
> > - funcs->prepare(crtc);
> > - else if (funcs->atomic_disable)
> > - funcs->atomic_disable(crtc, old_crtc_state);
> > - else if (funcs->disable)
> > - funcs->disable(crtc);
> > - else
> > - funcs->dpms(crtc, DRM_MODE_DPMS_OFF);
> > + if (funcs) {
>
> I don't think making funcs optional is a good idea. If you have a crtc
> with no functions implemented, it's not terribly useful.
>
> Also making functions optional just here is not going to help if we still
> require it everywhere else.
Should I remove the other occurrence of "if (funcs)" inside
disable_outputs() and drm_atomic_helper_commit_modeset_enables()? Both
functions, already had this before.
Best Regards
> -Daniel
>
> > + if (new_crtc_state->enable && funcs->prepare)
> > + funcs->prepare(crtc);
> > + else if (funcs->atomic_disable)
> > + funcs->atomic_disable(crtc, old_crtc_state);
> > + else if (funcs->disable)
> > + funcs->disable(crtc);
> > + else if (funcs->dpms)
> > + funcs->dpms(crtc, DRM_MODE_DPMS_OFF);
> > + }
> >
> > if (!(dev->irq_enabled && dev->num_crtcs))
> > continue;
> > @@ -1277,11 +1279,13 @@ void drm_atomic_helper_commit_modeset_enables(struct drm_device *dev,
> > if (new_crtc_state->enable) {
> > DRM_DEBUG_ATOMIC("enabling [CRTC:%d:%s]\n",
> > crtc->base.id, crtc->name);
> > -
> > - if (funcs->atomic_enable)
> > - funcs->atomic_enable(crtc, old_crtc_state);
> > - else
> > - funcs->commit(crtc);
> > + if (funcs) {
> > + if (funcs->atomic_enable)
> > + funcs->atomic_enable(crtc,
> > + old_crtc_state);
> > + else if (funcs->atomic_enable)
> > + funcs->commit(crtc);
> > + }
> > }
> > }
> >
> > --
> > 2.21.0
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch
--
Rodrigo Siqueira
https://siqueira.tech
Graduate Student
Department of Computer Science
University of S?o Paulo