On 2016年04月01日 19:47, Tomeu Vizoso wrote:

On 04/01/2016 01:26 PM, Mark yao wrote:

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On 2016年03月31日 16:08, Tomeu Vizoso wrote:

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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).

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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.

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ret = drm_atomic_helper_prepare_planes(dev, state); if (ret) return ret;

-- Ｍark Yao