[PATCH v4 1/2] dma-fence: allow signaling drivers to set fence timestamp

[Sumit Semwal]

Hi Veera,

On Wed, 20 Jan 2021 at 02:00, John Stultz <john.stultz at linaro.org> wrote:
>
> On Fri, Jan 15, 2021 at 4:31 PM Veera Sundaram Sankaran
> <veeras at codeaurora.org> wrote:
> >
> > Some drivers have hardware capability to get the precise HW timestamp
> > of certain events based on which the fences are triggered. The delta
> > between the event HW timestamp & current HW reference timestamp can
> > be used to calculate the timestamp in kernel's CLOCK_MONOTONIC time
> > domain. This allows it to set accurate timestamp factoring out any
> > software and IRQ latencies. Add a timestamp variant of fence signal
> > function, dma_fence_signal_timestamp to allow drivers to update the
> > precise timestamp for fences.

Thank you for the patches!

Daniel, Christian, Gustavo: if there are no objections, I will queue
up this series via drm-misc-next.

> >
> > Changes in v2:
> > - Add a new fence signal variant instead of modifying fence struct
> >
> > Changes in v3:
> > - Add timestamp domain information to commit-text and
> > dma_fence_signal_timestamp documentation
> >
> > Signed-off-by: Veera Sundaram Sankaran <veeras at codeaurora.org>
> > ---
> >  drivers/dma-buf/dma-fence.c | 70 ++++++++++++++++++++++++++++++++++++++++-----
> >  include/linux/dma-fence.h   |  3 ++
> >  2 files changed, 66 insertions(+), 7 deletions(-)
>
> Thanks for respinning this!
>
> Reviewed-by: John Stultz <john.stultz at linaro.org>
>
> -john

Best,
Sumit.