linux-kernel - Re: [PATCH] drm:amd:amdgpu: Fix missing bo unlock in failure path

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Date:   Mon, 24 Apr 2023 09:07:02 +0200
From:   Christian König <christian.koenig@....com>
To:     Sukrut Bellary <sukrut.bellary@...ux.com>, daniel@...ll.ch,
        airlied@...il.com, sumit.semwal@...aro.org, Hawking.Zhang@....com,
        Julia.Lawall@...ia.fr, dri-devel@...ts.freedesktop.org
Cc:     alexander.deucher@....com, Xinhui.Pan@....com,
        amd-gfx@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
        linux-media@...r.kernel.org, linaro-mm-sig@...ts.linaro.org
Subject: Re: [PATCH] drm:amd:amdgpu: Fix missing bo unlock in failure path

Am 24.04.23 um 07:59 schrieb Sukrut Bellary:
> smatch warning - inconsistent handling of buffer object reserve
> and unreserve.
>
> Signed-off-by: Sukrut Bellary <sukrut.bellary@...ux.com>

For now that patch is Reviewed-by: Christian König 
<christian.koenig@....com>.

But for the record mapping/unmapping the MQD like this is a very bad 
idea in the first place.

We could need to shuffle memory around for that during resume and that 
is not something we really want to do.

Christian.

> ---
>   drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
> index 278416acf060..5de44d7e92de 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/gfx_v8_0.c
> @@ -4686,8 +4686,10 @@ static int gfx_v8_0_kiq_resume(struct amdgpu_device *adev)
>   		return r;
>   
>   	r = amdgpu_bo_kmap(ring->mqd_obj, &ring->mqd_ptr);
> -	if (unlikely(r != 0))
> +	if (unlikely(r != 0)) {
> +		amdgpu_bo_unreserve(ring->mqd_obj);
>   		return r;
> +	}
>   
>   	gfx_v8_0_kiq_init_queue(ring);
>   	amdgpu_bo_kunmap(ring->mqd_obj);