Received-SPF: pass (google.com: domain of linux-kernel+bounces-127661-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45e3:2400::1 as permitted sender) client-ip=2604:1380:45e3:2400::1;
Message-ID: <4949bd54-8c32-4490-ab19-d38796d29ac1@collabora.com>
Date: Tue, 2 Apr 2024 11:50:53 +0200
Precedence: bulk
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH 1/3] media: mediatek: vcodec: fix h264 multi statless
 decoder smatch warning
To: Yunfei Dong <yunfei.dong@mediatek.com>,
 =?UTF-8?Q?N=C3=ADcolas_F_=2E_R_=2E_A_=2E_Prado?= <nfraprado@collabora.com>,
 Nicolas Dufresne <nicolas.dufresne@collabora.com>,
 Hans Verkuil <hverkuil-cisco@xs4all.nl>,
 Benjamin Gaignard <benjamin.gaignard@collabora.com>,
 Nathan Hebert <nhebert@chromium.org>
Cc: Hsin-Yi Wang <hsinyi@chromium.org>, Fritz Koenig <frkoenig@chromium.org>,
 Daniel Vetter <daniel@ffwll.ch>, Steve Cho <stevecho@chromium.org>,
 linux-media@vger.kernel.org, devicetree@vger.kernel.org,
 linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
 linux-mediatek@lists.infradead.org,
 Project_Global_Chrome_Upstream_Group@mediatek.com
References: <20240229095611.6698-1-yunfei.dong@mediatek.com>
 <20240229095611.6698-2-yunfei.dong@mediatek.com>
From: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Content-Language: en-US
In-Reply-To: <20240229095611.6698-2-yunfei.dong@mediatek.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit

Il 29/02/24 10:56, Yunfei Dong ha scritto:
> Fix smatch static checker warning for vdec_h264_req_multi_if.c.
> Leading to kernel crash when fb is NULL.
> 
> Fixes: 397edc703a10 ("media: mediatek: vcodec: add h264 decoder")
> Signed-off-by: Yunfei Dong <yunfei.dong@mediatek.com>
> ---
>   .../vcodec/decoder/vdec/vdec_h264_req_multi_if.c         | 9 +++++++--
>   1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/platform/mediatek/vcodec/decoder/vdec/vdec_h264_req_multi_if.c b/drivers/media/platform/mediatek/vcodec/decoder/vdec/vdec_h264_req_multi_if.c
> index 0e741e0dc8ba..ab8e708e0df1 100644
> --- a/drivers/media/platform/mediatek/vcodec/decoder/vdec/vdec_h264_req_multi_if.c
> +++ b/drivers/media/platform/mediatek/vcodec/decoder/vdec/vdec_h264_req_multi_if.c
> @@ -724,11 +724,16 @@ static int vdec_h264_slice_single_decode(void *h_vdec, struct mtk_vcodec_mem *bs
>   		return vpu_dec_reset(vpu);
>   
>   	fb = inst->ctx->dev->vdec_pdata->get_cap_buffer(inst->ctx);
> +	if (!fb) {
> +		mtk_vdec_err(inst->ctx, "fb buffer is NULL");
> +		return -EBUSY;
> +	}
> +
>   	src_buf_info = container_of(bs, struct mtk_video_dec_buf, bs_buffer);
>   	dst_buf_info = container_of(fb, struct mtk_video_dec_buf, frame_buffer);
>   
> -	y_fb_dma = fb ? (u64)fb->base_y.dma_addr : 0;
> -	c_fb_dma = fb ? (u64)fb->base_c.dma_addr : 0;

You're changing the behavior here, can you please explain why this change is valid
into the commit description?

Thanks,
Angelo

> +	y_fb_dma = (u64)fb->base_y.dma_addr;
> +	c_fb_dma = (u64)fb->base_c.dma_addr;
>   	mtk_vdec_debug(inst->ctx, "[h264-dec] [%d] y_dma=%llx c_dma=%llx",
>   		       inst->ctx->decoded_frame_cnt, y_fb_dma, c_fb_dma);
>