Quoting Rob Clark (2017-11-21 14:08:46) > If we are testing if a reservation object's fences have been > signaled with timeout=0 (non-blocking), we need to pass 0 for > timeout to dma_fence_wait_timeout(). > > Plus bonus spelling correction. > > Signed-off-by: Rob Clark <robdclark@xxxxxxxxx> > --- > drivers/dma-buf/reservation.c | 11 +++++++++-- > 1 file changed, 9 insertions(+), 2 deletions(-) > > diff --git a/drivers/dma-buf/reservation.c b/drivers/dma-buf/reservation.c > index dec3a815455d..71f51140a9ad 100644 > --- a/drivers/dma-buf/reservation.c > +++ b/drivers/dma-buf/reservation.c > @@ -420,7 +420,7 @@ EXPORT_SYMBOL_GPL(reservation_object_get_fences_rcu); > * > * RETURNS > * Returns -ERESTARTSYS if interrupted, 0 if the wait timed out, or > - * greater than zer on success. > + * greater than zero on success. > */ > long reservation_object_wait_timeout_rcu(struct reservation_object *obj, > bool wait_all, bool intr, > @@ -483,7 +483,14 @@ long reservation_object_wait_timeout_rcu(struct reservation_object *obj, > goto retry; > } > > - ret = dma_fence_wait_timeout(fence, intr, ret); > + /* > + * Note that dma_fence_wait_timeout() will return 1 if > + * the fence is already signaled, so in the wait_all > + * case when we go through the retry loop again, ret > + * will be greater than 0 and we don't want this to > + * cause _wait_timeout() to block > + */ > + ret = dma_fence_wait_timeout(fence, intr, timeout ? ret : 0); One should ask if we should just fix the interface to stop returning incorrect results (stop "correcting" a completion with 0 jiffies remaining as 1). A timeout can be distinguished by -ETIME (or your pick of errno). -Chris
