From: John Stultz <john.stultz@linaro.org>
To: Veera Sundaram Sankaran <veeras@codeaurora.org>
Cc: David Airlie <airlied@linux.ie>,
Gustavo Padovan <gustavo@padovan.org>,
dri-devel <dri-devel@lists.freedesktop.org>,
pdhaval@codeaurora.org, abhinavk@codeaurora.org,
Sean Paul <sean@poorly.run>,
linux-media <linux-media@vger.kernel.org>
Subject: Re: [PATCH v4 2/2] drm/drm_vblank: set the dma-fence timestamp during send_vblank_event
Date: Tue, 19 Jan 2021 12:31:19 -0800 [thread overview]
Message-ID: <CALAqxLX9Jh8NpXQwQ5ssBYuypbzzNg2OF+hPxxYfCnvzmzNOWg@mail.gmail.com> (raw)
In-Reply-To: <1610757107-11892-2-git-send-email-veeras@codeaurora.org>
On Fri, Jan 15, 2021 at 4:31 PM Veera Sundaram Sankaran
<veeras@codeaurora.org> wrote:
>
> The explicit out-fences in crtc are signaled as part of vblank event,
> indicating all framebuffers present on the Atomic Commit request are
> scanned out on the screen. Though the fence signal and the vblank event
> notification happens at the same time, triggered by the same hardware
> vsync event, the timestamp set in both are different. With drivers
> supporting precise vblank timestamp the difference between the two
> timestamps would be even higher. This might have an impact on use-mode
> frameworks using these fence timestamps for purposes other than simple
> buffer usage. For instance, the Android framework [1] uses the
> retire-fences as an alternative to vblank when frame-updates are in
> progress. Set the fence timestamp during send vblank event using a new
> drm_send_event_timestamp_locked variant to avoid discrepancies.
>
> [1] https://android.googlesource.com/platform/frameworks/native/+/master/
> services/surfaceflinger/Scheduler/Scheduler.cpp#397
>
> Changes in v2:
> - Use drm_send_event_timestamp_locked to update fence timestamp
> - add more information to commit text
>
> Changes in v3:
> - use same backend helper function for variants of drm_send_event to
> avoid code duplications
>
> Changes in v4:
> - remove WARN_ON from drm_send_event_timestamp_locked
>
> Signed-off-by: Veera Sundaram Sankaran <veeras@codeaurora.org>
> ---
Looks good, as expected no longer seeing the warning.
Reviewed-by: John Stultz <john.stultz@linaro.org>
thanks
-john
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
next prev parent reply other threads:[~2021-01-19 20:31 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-16 0:31 [PATCH v4 1/2] dma-fence: allow signaling drivers to set fence timestamp Veera Sundaram Sankaran
2021-01-16 0:31 ` [PATCH v4 2/2] drm/drm_vblank: set the dma-fence timestamp during send_vblank_event Veera Sundaram Sankaran
2021-01-19 20:31 ` John Stultz [this message]
2021-01-19 20:30 ` [PATCH v4 1/2] dma-fence: allow signaling drivers to set fence timestamp John Stultz
2021-01-21 14:00 ` Sumit Semwal
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CALAqxLX9Jh8NpXQwQ5ssBYuypbzzNg2OF+hPxxYfCnvzmzNOWg@mail.gmail.com \
--to=john.stultz@linaro.org \
--cc=abhinavk@codeaurora.org \
--cc=airlied@linux.ie \
--cc=dri-devel@lists.freedesktop.org \
--cc=gustavo@padovan.org \
--cc=linux-media@vger.kernel.org \
--cc=pdhaval@codeaurora.org \
--cc=sean@poorly.run \
--cc=veeras@codeaurora.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).