* Re: [PATCH] drm/rockchip: Return -EBUSY if there's already a pending flip event v2
@ 2016-04-01 11:47 ` Tomeu Vizoso
0 siblings, 0 replies; 10+ messages in thread
From: Tomeu Vizoso @ 2016-04-01 11:47 UTC (permalink / raw)
To: Mark yao, linux-kernel
Cc: David Airlie, Heiko Stuebner, dri-devel, linux-arm-kernel,
linux-rockchip
On 04/01/2016 01:26 PM, Mark yao wrote:
> On 2016年03月31日 16:08, Tomeu Vizoso wrote:
>> As per the docs, atomic_commit should return -EBUSY "if an asycnhronous
>> updated is requested and there is an earlier updated pending".
>>
>> v2: Use the status of the workqueue instead of vop->event, and don't add
>> a superfluous wait on the workqueue.
>>
>> Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
>> ---
>> drivers/gpu/drm/rockchip/rockchip_drm_fb.c | 3 +++
>> 1 file changed, 3 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_fb.c b/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
>> index 3b8f652698f8..285f8cd5afe1 100644
>> --- a/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
>> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
>> @@ -282,6 +282,9 @@ int rockchip_drm_atomic_commit(struct drm_device *dev,
>> struct rockchip_atomic_commit *commit = &private->commit;
>> int ret;
>>
>> + if (async && work_busy(&commit->work))
>> + return -EBUSY;
>> +
>
> Sorry for reply late.
>
> There is a comment on work_busy function describe :
>
> "the test result is unreliable and only useful as advisory hints or
> for debugging."
>
> I don't know if it's suitable to use it here, does some guys know it?
I'm not sure, but if the reason is the caveat explained in
find_worker_executing_work(), then it's probably safe (and would explain
how the function is used in other parts in the kernel).
> And then, the "flush_work(&commit->work);" is no needed if return -EBUSY
> here.
> you can remove it at this patch.
We still need to wait if it's being called in sync mode.
Regards,
Tomeu
>> ret = drm_atomic_helper_prepare_planes(dev, state);
>> if (ret)
>> return ret;
>
>
>
> --
> Ｍark Yao
>
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH] drm/rockchip: Return -EBUSY if there's already a pending flip event v2
@ 2016-04-01 11:47 ` Tomeu Vizoso
0 siblings, 0 replies; 10+ messages in thread
From: Tomeu Vizoso @ 2016-04-01 11:47 UTC (permalink / raw)
To: linux-arm-kernel
On 04/01/2016 01:26 PM, Mark yao wrote:
> On 2016?03?31? 16:08, Tomeu Vizoso wrote:
>> As per the docs, atomic_commit should return -EBUSY "if an asycnhronous
>> updated is requested and there is an earlier updated pending".
>>
>> v2: Use the status of the workqueue instead of vop->event, and don't add
>> a superfluous wait on the workqueue.
>>
>> Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
>> ---
>> drivers/gpu/drm/rockchip/rockchip_drm_fb.c | 3 +++
>> 1 file changed, 3 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_fb.c b/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
>> index 3b8f652698f8..285f8cd5afe1 100644
>> --- a/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
>> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
>> @@ -282,6 +282,9 @@ int rockchip_drm_atomic_commit(struct drm_device *dev,
>> struct rockchip_atomic_commit *commit = &private->commit;
>> int ret;
>>
>> + if (async && work_busy(&commit->work))
>> + return -EBUSY;
>> +
>
> Sorry for reply late.
>
> There is a comment on work_busy function describe :
>
> "the test result is unreliable and only useful as advisory hints or
> for debugging."
>
> I don't know if it's suitable to use it here, does some guys know it?
I'm not sure, but if the reason is the caveat explained in
find_worker_executing_work(), then it's probably safe (and would explain
how the function is used in other parts in the kernel).
> And then, the "flush_work(&commit->work);" is no needed if return -EBUSY
> here.
> you can remove it at this patch.
We still need to wait if it's being called in sync mode.
Regards,
Tomeu
>> ret = drm_atomic_helper_prepare_planes(dev, state);
>> if (ret)
>> return ret;
>
>
>
> --
> ?ark Yao
>
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] drm/rockchip: Return -EBUSY if there's already a pending flip event v2
2016-04-01 11:47 ` Tomeu Vizoso
(?)
@ 2016-04-01 11:54 ` Mark yao
-1 siblings, 0 replies; 10+ messages in thread
From: Mark yao @ 2016-04-01 11:54 UTC (permalink / raw)
To: Tomeu Vizoso, linux-kernel; +Cc: linux-rockchip, dri-devel, linux-arm-kernel
On 2016年04月01日 19:47, Tomeu Vizoso wrote:
> On 04/01/2016 01:26 PM, Mark yao wrote:
>> On 2016年03月31日 16:08, Tomeu Vizoso wrote:
>>> As per the docs, atomic_commit should return -EBUSY "if an asycnhronous
>>> updated is requested and there is an earlier updated pending".
>>>
>>> v2: Use the status of the workqueue instead of vop->event, and don't add
>>> a superfluous wait on the workqueue.
>>>
>>> Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
>>> ---
>>> drivers/gpu/drm/rockchip/rockchip_drm_fb.c | 3 +++
>>> 1 file changed, 3 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_fb.c b/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
>>> index 3b8f652698f8..285f8cd5afe1 100644
>>> --- a/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
>>> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
>>> @@ -282,6 +282,9 @@ int rockchip_drm_atomic_commit(struct drm_device *dev,
>>> struct rockchip_atomic_commit *commit = &private->commit;
>>> int ret;
>>>
>>> + if (async && work_busy(&commit->work))
>>> + return -EBUSY;
>>> +
>> Sorry for reply late.
>>
>> There is a comment on work_busy function describe :
>>
>> "the test result is unreliable and only useful as advisory hints or
>> for debugging."
>>
>> I don't know if it's suitable to use it here, does some guys know it?
> I'm not sure, but if the reason is the caveat explained in
> find_worker_executing_work(), then it's probably safe (and would explain
> how the function is used in other parts in the kernel).
>
>> And then, the "flush_work(&commit->work);" is no needed if return -EBUSY
>> here.
>> you can remove it at this patch.
> We still need to wait if it's being called in sync mode.
>
> Regards,
>
> Tomeu
Hi TomeuＨｉ
on sync mode, flush is no needed, because that:
1, there is mutex_lock/mutex_unlock on this context, So only single
process run into commit work;
2, sync mode will block on:
rockchip_atomic_commit_complete-->rockchip_atomic_wait_for_complete,
Thanks.
>
>>> ret = drm_atomic_helper_prepare_planes(dev, state);
>>> if (ret)
>>> return ret;
>>
>>
>> --
>> Ｍark Yao
>>
>
>
>
--
Ｍark Yao
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] drm/rockchip: Return -EBUSY if there's already a pending flip event v2
@ 2016-04-01 11:54 ` Mark yao
0 siblings, 0 replies; 10+ messages in thread
From: Mark yao @ 2016-04-01 11:54 UTC (permalink / raw)
To: Tomeu Vizoso, linux-kernel
Cc: David Airlie, Heiko Stuebner, dri-devel, linux-arm-kernel,
linux-rockchip
On 2016年04月01日 19:47, Tomeu Vizoso wrote:
> On 04/01/2016 01:26 PM, Mark yao wrote:
>> On 2016年03月31日 16:08, Tomeu Vizoso wrote:
>>> As per the docs, atomic_commit should return -EBUSY "if an asycnhronous
>>> updated is requested and there is an earlier updated pending".
>>>
>>> v2: Use the status of the workqueue instead of vop->event, and don't add
>>> a superfluous wait on the workqueue.
>>>
>>> Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
>>> ---
>>> drivers/gpu/drm/rockchip/rockchip_drm_fb.c | 3 +++
>>> 1 file changed, 3 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_fb.c b/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
>>> index 3b8f652698f8..285f8cd5afe1 100644
>>> --- a/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
>>> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
>>> @@ -282,6 +282,9 @@ int rockchip_drm_atomic_commit(struct drm_device *dev,
>>> struct rockchip_atomic_commit *commit = &private->commit;
>>> int ret;
>>>
>>> + if (async && work_busy(&commit->work))
>>> + return -EBUSY;
>>> +
>> Sorry for reply late.
>>
>> There is a comment on work_busy function describe :
>>
>> "the test result is unreliable and only useful as advisory hints or
>> for debugging."
>>
>> I don't know if it's suitable to use it here, does some guys know it?
> I'm not sure, but if the reason is the caveat explained in
> find_worker_executing_work(), then it's probably safe (and would explain
> how the function is used in other parts in the kernel).
>
>> And then, the "flush_work(&commit->work);" is no needed if return -EBUSY
>> here.
>> you can remove it at this patch.
> We still need to wait if it's being called in sync mode.
>
> Regards,
>
> Tomeu
Hi TomeuＨｉ
on sync mode, flush is no needed, because that:
1, there is mutex_lock/mutex_unlock on this context, So only single
process run into commit work;
2, sync mode will block on:
rockchip_atomic_commit_complete-->rockchip_atomic_wait_for_complete,
Thanks.
>
>>> ret = drm_atomic_helper_prepare_planes(dev, state);
>>> if (ret)
>>> return ret;
>>
>>
>> --
>> Ｍark Yao
>>
>
>
>
--
Ｍark Yao
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH] drm/rockchip: Return -EBUSY if there's already a pending flip event v2
@ 2016-04-01 11:54 ` Mark yao
0 siblings, 0 replies; 10+ messages in thread
From: Mark yao @ 2016-04-01 11:54 UTC (permalink / raw)
To: linux-arm-kernel
On 2016?04?01? 19:47, Tomeu Vizoso wrote:
> On 04/01/2016 01:26 PM, Mark yao wrote:
>> On 2016?03?31? 16:08, Tomeu Vizoso wrote:
>>> As per the docs, atomic_commit should return -EBUSY "if an asycnhronous
>>> updated is requested and there is an earlier updated pending".
>>>
>>> v2: Use the status of the workqueue instead of vop->event, and don't add
>>> a superfluous wait on the workqueue.
>>>
>>> Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
>>> ---
>>> drivers/gpu/drm/rockchip/rockchip_drm_fb.c | 3 +++
>>> 1 file changed, 3 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_fb.c b/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
>>> index 3b8f652698f8..285f8cd5afe1 100644
>>> --- a/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
>>> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_fb.c
>>> @@ -282,6 +282,9 @@ int rockchip_drm_atomic_commit(struct drm_device *dev,
>>> struct rockchip_atomic_commit *commit = &private->commit;
>>> int ret;
>>>
>>> + if (async && work_busy(&commit->work))
>>> + return -EBUSY;
>>> +
>> Sorry for reply late.
>>
>> There is a comment on work_busy function describe :
>>
>> "the test result is unreliable and only useful as advisory hints or
>> for debugging."
>>
>> I don't know if it's suitable to use it here, does some guys know it?
> I'm not sure, but if the reason is the caveat explained in
> find_worker_executing_work(), then it's probably safe (and would explain
> how the function is used in other parts in the kernel).
>
>> And then, the "flush_work(&commit->work);" is no needed if return -EBUSY
>> here.
>> you can remove it at this patch.
> We still need to wait if it's being called in sync mode.
>
> Regards,
>
> Tomeu
Hi Tomeu??
on sync mode, flush is no needed, because that:
1, there is mutex_lock/mutex_unlock on this context, So only single
process run into commit work;
2, sync mode will block on:
rockchip_atomic_commit_complete-->rockchip_atomic_wait_for_complete,
Thanks.
>
>>> ret = drm_atomic_helper_prepare_planes(dev, state);
>>> if (ret)
>>> return ret;
>>
>>
>> --
>> ?ark Yao
>>
>
>
>
--
?ark Yao
^ permalink raw reply [flat|nested] 10+ messages in thread