[PATCH 04/25] drm/vkms: Annotate vblank timer

[Daniel Vetter]

On Tue, Jul 14, 2020 at 11:57 AM Melissa Wen <melissa.srw at gmail.com> wrote:
>
> On 07/12, Rodrigo Siqueira wrote:
> > Hi,
> >
> > Everything looks fine to me, I just noticed that the amdgpu patches did
> > not apply smoothly, however it was trivial to fix the issues.
> >
> > Reviewed-by: Rodrigo Siqueira <rodrigosiqueiramelo at gmail.com>
> >
> > Melissa,
> > Since you are using vkms regularly, could you test this patch and review
> > it? Remember to add your Tested-by when you finish.
> >
> Hi,
>
> I've applied the patch series, ran some tests on vkms, and found no
> issues. I mean, things have remained stable.
>
> Tested-by: Melissa Wen <melissa.srw at gmail.com>

Did you test with CONFIG_PROVE_LOCKING enabled in the kernel .config?
Without that enabled, there's not really any change here, but with
that enabled there might be some lockdep splats in dmesg indicating a
problem.

Thanks, Daniel
>
> > Thanks
> >
> > On 07/07, Daniel Vetter wrote:
> > > This is needed to signal the fences from page flips, annotate it
> > > accordingly. We need to annotate entire timer callback since if we get
> > > stuck anywhere in there, then the timer stops, and hence fences stop.
> > > Just annotating the top part that does the vblank handling isn't
> > > enough.
> > >
> > > Cc: linux-media at vger.kernel.org
> > > Cc: linaro-mm-sig at lists.linaro.org
> > > Cc: linux-rdma at vger.kernel.org
> > > Cc: amd-gfx at lists.freedesktop.org
> > > Cc: intel-gfx at lists.freedesktop.org
> > > Cc: Chris Wilson <chris at chris-wilson.co.uk>
> > > Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> > > Cc: Christian König <christian.koenig at amd.com>
> > > Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> > > Cc: Rodrigo Siqueira <rodrigosiqueiramelo at gmail.com>
> > > Cc: Haneen Mohammed <hamohammed.sa at gmail.com>
> > > Cc: Daniel Vetter <daniel at ffwll.ch>
> > > ---
> > >  drivers/gpu/drm/vkms/vkms_crtc.c | 8 +++++++-
> > >  1 file changed, 7 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/gpu/drm/vkms/vkms_crtc.c b/drivers/gpu/drm/vkms/vkms_crtc.c
> > > index ac85e17428f8..a53a40848a72 100644
> > > --- a/drivers/gpu/drm/vkms/vkms_crtc.c
> > > +++ b/drivers/gpu/drm/vkms/vkms_crtc.c
> > > @@ -1,5 +1,7 @@
> > >  // SPDX-License-Identifier: GPL-2.0+
> > >
> > > +#include <linux/dma-fence.h>
> > > +
> > >  #include <drm/drm_atomic.h>
> > >  #include <drm/drm_atomic_helper.h>
> > >  #include <drm/drm_probe_helper.h>
> > > @@ -14,7 +16,9 @@ static enum hrtimer_restart vkms_vblank_simulate(struct hrtimer *timer)
> > >     struct drm_crtc *crtc = &output->crtc;
> > >     struct vkms_crtc_state *state;
> > >     u64 ret_overrun;
> > > -   bool ret;
> > > +   bool ret, fence_cookie;
> > > +
> > > +   fence_cookie = dma_fence_begin_signalling();
> > >
> > >     ret_overrun = hrtimer_forward_now(&output->vblank_hrtimer,
> > >                                       output->period_ns);
> > > @@ -49,6 +53,8 @@ static enum hrtimer_restart vkms_vblank_simulate(struct hrtimer *timer)
> > >                     DRM_DEBUG_DRIVER("Composer worker already queued\n");
> > >     }
> > >
> > > +   dma_fence_end_signalling(fence_cookie);
> > > +
> > >     return HRTIMER_RESTART;
> > >  }
> > >
> > > --
> > > 2.27.0
> > >
> >
> > --
> > Rodrigo Siqueira
> > https://siqueira.tech
>
>


-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch