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From:   Brian Starkey <Brian.Starkey@arm.com>
To:     "Lowry Li (Arm Technology China)" <Lowry.Li@arm.com>
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Subject: Re: [PATCH v1 2/2] drm: Clear the fence pointer when writeback job
 signaled
Thread-Topic: [PATCH v1 2/2] drm: Clear the fence pointer when writeback job
 signaled
Thread-Index: AQHVR4/KbU4UCRFzvkaBT5qon3yv66bktjIA
Date:   Wed, 31 Jul 2019 13:20:04 +0000
Message-ID: <20190731132002.dut5mdsqgh7b75iv@DESKTOP-E1NTVVP.localdomain>
References: <1564571048-15029-1-git-send-email-lowry.li@arm.com>
 <1564571048-15029-3-git-send-email-lowry.li@arm.com>
In-Reply-To: <1564571048-15029-3-git-send-email-lowry.li@arm.com>
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Hi Lowry,

Thanks for this cleanup.

On Wed, Jul 31, 2019 at 11:04:45AM +0000, Lowry Li (Arm Technology China) w=
rote:
> During it signals the completion of a writeback job, after releasing
> the out_fence, we'd clear the pointer.
>=20
> Check if fence left over in drm_writeback_cleanup_job(), release it.
>=20
> Signed-off-by: Lowry Li (Arm Technology China) <lowry.li@arm.com>
> ---
>  drivers/gpu/drm/drm_writeback.c | 23 +++++++++++++++--------
>  1 file changed, 15 insertions(+), 8 deletions(-)
>=20
> diff --git a/drivers/gpu/drm/drm_writeback.c b/drivers/gpu/drm/drm_writeb=
ack.c
> index ff138b6..43d9e3b 100644
> --- a/drivers/gpu/drm/drm_writeback.c
> +++ b/drivers/gpu/drm/drm_writeback.c
> @@ -324,6 +324,9 @@ void drm_writeback_cleanup_job(struct drm_writeback_j=
ob *job)
>  	if (job->fb)
>  		drm_framebuffer_put(job->fb);
> =20
> +	if (job->out_fence)

I'm thinking it might be a good idea to signal the fence with an error
here, if it's not already signaled. Otherwise, if there's someone
waiting (which there shouldn't be), they're going to be waiting a very
long time :-)

Thanks,
-Brian

> +		dma_fence_put(job->out_fence);
> +
>  	kfree(job);
>  }