Re: [PATCH] drm/vblank: Simplify drm_dev_has_vblank()
On Wed, Apr 05, 2023 at 12:00:23AM +0300, Ville Syrjälä wrote: > On Tue, Apr 04, 2023 at 10:46:00PM +0200, Daniel Vetter wrote: > > On Mon, Apr 03, 2023 at 09:07:35AM -0700, Rob Clark wrote: > > > From: Rob Clark > > > > > > What does vblank have to do with num_crtcs? Well, this was technically > > > correct, but you'd have to go look at where num_crtcs is initialized to > > > understand why. Lets just replace it with the simpler and more obvious > > > check. > > > > If you want to fix this, then I think the right fix is to rename num_crtcs > > to be something like num_vblank_crtcs. It's a historical accident back > > when vblanks without kms was a thing. > > > > Plan B is someone gets really busy and fixes up the entire vblank mess and > > moves it into drm_crtc struct. Now that the dri1 drivers are gone we could > > indeed do that. > > And easy first step could to simply wrap all the naked > &dev->vblank[drm_crtc_index()] things into a function > call with some cocci/etc. That way most of the vblank > code doesn't need to care where that thing actually lives. Yeah I think that might work out. Roughly: - Wrap all the drm_vblank_crtc lookups - Emebed it into drm_crtc, delete the drm_device->vblank array - rename drm_device->num_crtc to something more meaningful maybe and move into drm_modeset_config The big holdup always was step 2 because we still had to care about legacy drivers without drm_crtc, which meant you'd have to have two paths, which was kinda really annoying. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch
Re: [PATCH] drm/vblank: Simplify drm_dev_has_vblank()
On Tue, Apr 04, 2023 at 10:46:00PM +0200, Daniel Vetter wrote: > On Mon, Apr 03, 2023 at 09:07:35AM -0700, Rob Clark wrote: > > From: Rob Clark > > > > What does vblank have to do with num_crtcs? Well, this was technically > > correct, but you'd have to go look at where num_crtcs is initialized to > > understand why. Lets just replace it with the simpler and more obvious > > check. > > If you want to fix this, then I think the right fix is to rename num_crtcs > to be something like num_vblank_crtcs. It's a historical accident back > when vblanks without kms was a thing. > > Plan B is someone gets really busy and fixes up the entire vblank mess and > moves it into drm_crtc struct. Now that the dri1 drivers are gone we could > indeed do that. And easy first step could to simply wrap all the naked &dev->vblank[drm_crtc_index()] things into a function call with some cocci/etc. That way most of the vblank code doesn't need to care where that thing actually lives. -- Ville Syrjälä Intel
Re: [PATCH] drm/vblank: Simplify drm_dev_has_vblank()
On Mon, Apr 03, 2023 at 09:07:35AM -0700, Rob Clark wrote:
> From: Rob Clark
>
> What does vblank have to do with num_crtcs? Well, this was technically
> correct, but you'd have to go look at where num_crtcs is initialized to
> understand why. Lets just replace it with the simpler and more obvious
> check.
If you want to fix this, then I think the right fix is to rename num_crtcs
to be something like num_vblank_crtcs. It's a historical accident back
when vblanks without kms was a thing.
Plan B is someone gets really busy and fixes up the entire vblank mess and
moves it into drm_crtc struct. Now that the dri1 drivers are gone we could
indeed do that.
Or maybe instead a patch to improve the kerneldoc for drm_dev->num_crtc?
-Daniel
> Signed-off-by: Rob Clark
> ---
> drivers/gpu/drm/drm_vblank.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
> index 877e2067534f..ad34c235d853 100644
> --- a/drivers/gpu/drm/drm_vblank.c
> +++ b/drivers/gpu/drm/drm_vblank.c
> @@ -575,7 +575,7 @@ EXPORT_SYMBOL(drm_vblank_init);
> */
> bool drm_dev_has_vblank(const struct drm_device *dev)
> {
> - return dev->num_crtcs != 0;
> + return !!dev->vblank;
> }
> EXPORT_SYMBOL(drm_dev_has_vblank);
>
> --
> 2.39.2
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
Re: [PATCH] drm/vblank: Simplify drm_dev_has_vblank()
On 4/3/23 09:23, Ville Syrjälä wrote:
> On Mon, Apr 03, 2023 at 09:07:35AM -0700, Rob Clark wrote:
>> From: Rob Clark
>>
>> What does vblank have to do with num_crtcs? Well, this was technically
>> correct, but you'd have to go look at where num_crtcs is initialized to
>> understand why. Lets just replace it with the simpler and more obvious
>> check.
>>
>> Signed-off-by: Rob Clark
>> ---
>> drivers/gpu/drm/drm_vblank.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
>> index 877e2067534f..ad34c235d853 100644
>> --- a/drivers/gpu/drm/drm_vblank.c
>> +++ b/drivers/gpu/drm/drm_vblank.c
>> @@ -575,7 +575,7 @@ EXPORT_SYMBOL(drm_vblank_init);
>> */
>> bool drm_dev_has_vblank(const struct drm_device *dev)
>> {
>> -return dev->num_crtcs != 0;
>> +return !!dev->vblank;
>
> The compiler knows how to turn things into a boolean.
>> Or I guess if we want to be a bit more explicit we could
> write this as
> return dev->vblank != NULL;
> but IIRC that will make checkpatch complain because of
> someone's personal taste.
checkpatch isn't an absolute thing. :)
--
~Randy
Re: [PATCH] drm/vblank: Simplify drm_dev_has_vblank()
On Mon, Apr 03, 2023 at 09:07:35AM -0700, Rob Clark wrote:
> From: Rob Clark
>
> What does vblank have to do with num_crtcs? Well, this was technically
> correct, but you'd have to go look at where num_crtcs is initialized to
> understand why. Lets just replace it with the simpler and more obvious
> check.
>
> Signed-off-by: Rob Clark
> ---
> drivers/gpu/drm/drm_vblank.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
> index 877e2067534f..ad34c235d853 100644
> --- a/drivers/gpu/drm/drm_vblank.c
> +++ b/drivers/gpu/drm/drm_vblank.c
> @@ -575,7 +575,7 @@ EXPORT_SYMBOL(drm_vblank_init);
> */
> bool drm_dev_has_vblank(const struct drm_device *dev)
> {
> - return dev->num_crtcs != 0;
> + return !!dev->vblank;
The compiler knows how to turn things into a boolean.
Or I guess if we want to be a bit more explicit we could
write this as
return dev->vblank != NULL;
but IIRC that will make checkpatch complain because of
someone's personal taste.
> }
> EXPORT_SYMBOL(drm_dev_has_vblank);
>
> --
> 2.39.2
--
Ville Syrjälä
Intel
[PATCH] drm/vblank: Simplify drm_dev_has_vblank()
From: Rob Clark
What does vblank have to do with num_crtcs? Well, this was technically
correct, but you'd have to go look at where num_crtcs is initialized to
understand why. Lets just replace it with the simpler and more obvious
check.
Signed-off-by: Rob Clark
---
drivers/gpu/drm/drm_vblank.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
index 877e2067534f..ad34c235d853 100644
--- a/drivers/gpu/drm/drm_vblank.c
+++ b/drivers/gpu/drm/drm_vblank.c
@@ -575,7 +575,7 @@ EXPORT_SYMBOL(drm_vblank_init);
*/
bool drm_dev_has_vblank(const struct drm_device *dev)
{
- return dev->num_crtcs != 0;
+ return !!dev->vblank;
}
EXPORT_SYMBOL(drm_dev_has_vblank);
--
2.39.2
