On 2021-10-26 13:07, Stylon Wang wrote: > [Why] > In GNOME Settings->Display the switching from mirror mode to single display > occasionally causes wait_for_completion_interruptible_timeout() to return > -ERESTARTSYS and fails atomic check. > > [How] > Replace the call with wait_for_completion_timeout() since the waiting for > hw_done and flip_done completion doesn't need to worry about interruption > from signal. > > Signed-off-by: Stylon Wang <stylon.w...@amd.com> > --- > drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c > b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c > index 4cd64529b180..b8f4ff323de1 100644 > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c > +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c > @@ -9844,10 +9844,10 @@ static int do_aquire_global_lock(struct drm_device > *dev, > * Make sure all pending HW programming completed and > * page flips done > */ > - ret = > wait_for_completion_interruptible_timeout(&commit->hw_done, 10*HZ); > + ret = wait_for_completion_timeout(&commit->hw_done, 10*HZ); > > if (ret > 0) > - ret = wait_for_completion_interruptible_timeout( > + ret = wait_for_completion_timeout( > &commit->flip_done, 10*HZ); > > if (ret == 0) >
The *_interruptible_* variant is needed so that the display manager process can be killed while it's waiting here, which could take up to 10 seconds (per the timeout). What's the problem with -ERESTARTSYS? Either the ioctl should be restarted automatically, or if it bounces back to user space, that needs to be able to retry the ioctl while it returns -1 and errno == EINTR. drmIoctl handles this transparently. -- Earthling Michel Dänzer | https://redhat.com Libre software enthusiast | Mesa and Xwayland developer
