On Tue, Jul 20, 2021 at 8:26 PM Rob Clark <robdclark@xxxxxxxxx> wrote: > > On Tue, Jul 20, 2021 at 11:03 AM Christian König > <ckoenig.leichtzumerken@xxxxxxxxx> wrote: > > > > Hi Rob, > > > > Am 20.07.21 um 17:07 schrieb Rob Clark: > > > From: Rob Clark <robdclark@xxxxxxxxxxxx> > > > > > > Somehow we had neither ->wait() nor dma_fence_signal() calls, and no > > > one noticed. Oops. > > > > > > I'm not sure if that is a good idea. > > > > The dma_fence->wait() callback is pretty much deprecated and should not > > be used any more. > > > > What exactly do you need that for? > > Well, the alternative is to track the set of fences which have > signalling enabled, and then figure out which ones to signal, which > seems like a lot more work, vs just re-purposing the wait > implementation we already have for non-dma_fence cases ;-) > > Why is the ->wait() callback (pretty much) deprecated? Because if you need it that means for your driver dma_fence_add_cb is broken, which means a _lot_ of things don't work. Like dma_buf poll (compositors have patches to start using that), and I think drm/scheduler also becomes rather unhappy. It essentially exists only for old drivers where ->enable_signalling is unreliable and we paper over that with a retry loop in ->wait and pray no one notices that it's too butchered. The proper fix is to have a driver thread to guarantee that ->enable_signalling works reliable, so you don't need a ->wait. Can you type up a kerneldoc patch for dma_fence_ops->wait to hammer this in please? -Daniel > > BR, > -R > > > Regards, > > Christian. > > > > > > > > Note that this removes the !timeout case, which has not been used in > > > a long time. > > > > > > > > > > Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx> > > > --- > > > drivers/gpu/drm/msm/msm_fence.c | 59 +++++++++++++++++++-------------- > > > 1 file changed, 34 insertions(+), 25 deletions(-) > > > > > > diff --git a/drivers/gpu/drm/msm/msm_fence.c b/drivers/gpu/drm/msm/msm_fence.c > > > index cd59a5918038..8ee96b90ded6 100644 > > > --- a/drivers/gpu/drm/msm/msm_fence.c > > > +++ b/drivers/gpu/drm/msm/msm_fence.c > > > @@ -38,11 +38,10 @@ static inline bool fence_completed(struct msm_fence_context *fctx, uint32_t fenc > > > return (int32_t)(fctx->completed_fence - fence) >= 0; > > > } > > > > > > -/* legacy path for WAIT_FENCE ioctl: */ > > > -int msm_wait_fence(struct msm_fence_context *fctx, uint32_t fence, > > > - ktime_t *timeout, bool interruptible) > > > +static signed long wait_fence(struct msm_fence_context *fctx, uint32_t fence, > > > + signed long remaining_jiffies, bool interruptible) > > > { > > > - int ret; > > > + signed long ret; > > > > > > if (fence > fctx->last_fence) { > > > DRM_ERROR_RATELIMITED("%s: waiting on invalid fence: %u (of %u)\n", > > > @@ -50,33 +49,34 @@ int msm_wait_fence(struct msm_fence_context *fctx, uint32_t fence, > > > return -EINVAL; > > > } > > > > > > - if (!timeout) { > > > - /* no-wait: */ > > > - ret = fence_completed(fctx, fence) ? 0 : -EBUSY; > > > + if (interruptible) { > > > + ret = wait_event_interruptible_timeout(fctx->event, > > > + fence_completed(fctx, fence), > > > + remaining_jiffies); > > > } else { > > > - unsigned long remaining_jiffies = timeout_to_jiffies(timeout); > > > - > > > - if (interruptible) > > > - ret = wait_event_interruptible_timeout(fctx->event, > > > - fence_completed(fctx, fence), > > > - remaining_jiffies); > > > - else > > > - ret = wait_event_timeout(fctx->event, > > > - fence_completed(fctx, fence), > > > - remaining_jiffies); > > > - > > > - if (ret == 0) { > > > - DBG("timeout waiting for fence: %u (completed: %u)", > > > - fence, fctx->completed_fence); > > > - ret = -ETIMEDOUT; > > > - } else if (ret != -ERESTARTSYS) { > > > - ret = 0; > > > - } > > > + ret = wait_event_timeout(fctx->event, > > > + fence_completed(fctx, fence), > > > + remaining_jiffies); > > > + } > > > + > > > + if (ret == 0) { > > > + DBG("timeout waiting for fence: %u (completed: %u)", > > > + fence, fctx->completed_fence); > > > + ret = -ETIMEDOUT; > > > + } else if (ret != -ERESTARTSYS) { > > > + ret = 0; > > > } > > > > > > return ret; > > > } > > > > > > +/* legacy path for WAIT_FENCE ioctl: */ > > > +int msm_wait_fence(struct msm_fence_context *fctx, uint32_t fence, > > > + ktime_t *timeout, bool interruptible) > > > +{ > > > + return wait_fence(fctx, fence, timeout_to_jiffies(timeout), interruptible); > > > +} > > > + > > > /* called from workqueue */ > > > void msm_update_fence(struct msm_fence_context *fctx, uint32_t fence) > > > { > > > @@ -114,10 +114,19 @@ static bool msm_fence_signaled(struct dma_fence *fence) > > > return fence_completed(f->fctx, f->base.seqno); > > > } > > > > > > +static signed long msm_fence_wait(struct dma_fence *fence, bool intr, > > > + signed long timeout) > > > +{ > > > + struct msm_fence *f = to_msm_fence(fence); > > > + > > > + return wait_fence(f->fctx, fence->seqno, timeout, intr); > > > +} > > > + > > > static const struct dma_fence_ops msm_fence_ops = { > > > .get_driver_name = msm_fence_get_driver_name, > > > .get_timeline_name = msm_fence_get_timeline_name, > > > .signaled = msm_fence_signaled, > > > + .wait = msm_fence_wait, > > > }; > > > > > > struct dma_fence * > > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch