Subject: Re: [PATCH 1/1] drm/radeon: check return value of radeon_ring_lock
To: Pan Bian <bianpan201603@163.com>,
        Alex Deucher <alexander.deucher@amd.com>,
        David Airlie <airlied@linux.ie>
References: <1493023085-11901-1-git-send-email-bianpan201603@163.com>
CC: <amd-gfx@lists.freedesktop.org>, <dri-devel@lists.freedesktop.org>,
        <linux-kernel@vger.kernel.org>, Pan Bian <bianpan2016@163.com>
From: =?UTF-8?Q?Christian_K=c3=b6nig?= <christian.koenig@amd.com>
Message-ID: <569d0101-6caf-9354-4e7f-51ebfef5dce6@amd.com>
Date: Mon, 24 Apr 2017 11:08:02 +0200
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Am 24.04.2017 um 10:38 schrieb Pan Bian:
> From: Pan Bian <bianpan2016@163.com>
>
> Function radeon_ring_lock() returns an errno on failure, and its return
> value should be validated. However, in functions r420_cp_errata_init()
> and r420_cp_errata_fini(), its return value is not checked. This patch
> adds the checks.
>
> Signed-off-by: Pan Bian <bianpan2016@163.com>

Reviewed-by: Christian K?nig <christian.koenig@amd.com>

> ---
>   drivers/gpu/drm/radeon/r420.c | 8 ++++++--
>   1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/r420.c b/drivers/gpu/drm/radeon/r420.c
> index 2828605..391c764 100644
> --- a/drivers/gpu/drm/radeon/r420.c
> +++ b/drivers/gpu/drm/radeon/r420.c
> @@ -206,6 +206,7 @@ static void r420_clock_resume(struct radeon_device *rdev)
>   
>   static void r420_cp_errata_init(struct radeon_device *rdev)
>   {
> +	int r;
>   	struct radeon_ring *ring = &rdev->ring[RADEON_RING_TYPE_GFX_INDEX];
>   
>   	/* RV410 and R420 can lock up if CP DMA to host memory happens
> @@ -215,7 +216,8 @@ static void r420_cp_errata_init(struct radeon_device *rdev)
>   	 * of the CP init, apparently.
>   	 */
>   	radeon_scratch_get(rdev, &rdev->config.r300.resync_scratch);
> -	radeon_ring_lock(rdev, ring, 8);
> +	r = radeon_ring_lock(rdev, ring, 8);
> +	WARN_ON(r);
>   	radeon_ring_write(ring, PACKET0(R300_CP_RESYNC_ADDR, 1));
>   	radeon_ring_write(ring, rdev->config.r300.resync_scratch);
>   	radeon_ring_write(ring, 0xDEADBEEF);
> @@ -224,12 +226,14 @@ static void r420_cp_errata_init(struct radeon_device *rdev)
>   
>   static void r420_cp_errata_fini(struct radeon_device *rdev)
>   {
> +	int r;
>   	struct radeon_ring *ring = &rdev->ring[RADEON_RING_TYPE_GFX_INDEX];
>   
>   	/* Catch the RESYNC we dispatched all the way back,
>   	 * at the very beginning of the CP init.
>   	 */
> -	radeon_ring_lock(rdev, ring, 8);
> +	r = radeon_ring_lock(rdev, ring, 8);
> +	WARN_ON(r);
>   	radeon_ring_write(ring, PACKET0(R300_RB3D_DSTCACHE_CTLSTAT, 0));
>   	radeon_ring_write(ring, R300_RB3D_DC_FINISH);
>   	radeon_ring_unlock_commit(rdev, ring, false);