Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <1800775a-5788-b60b-87cb-9b09c7e7c177@amd.com>
Date:   Thu, 5 Jan 2023 14:19:50 -0500
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.6.1
Subject: Re: [PATCH -next] drm/amd/display: Remove redundant assignment to
 variable dc
Content-Language: en-US
To:     Yi Yang <yiyang13@huawei.com>, sunpeng.li@amd.com,
        Rodrigo.Siqueira@amd.com, alexander.deucher@amd.com,
        christian.koenig@amd.com, Xinhui.Pan@amd.com, airlied@gmail.com,
        daniel@ffwll.ch
Cc:     amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org
References: <20221216102318.197994-1-yiyang13@huawei.com>
From:   Harry Wentland <harry.wentland@amd.com>
In-Reply-To: <20221216102318.197994-1-yiyang13@huawei.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?NFBDYjBYMFBaRW1KUDJGRDM3bGNCZjZTYXJRbU8wNjVRbGRRQmtUK0l6Q2Yy?=
 =?utf-8?B?QlpTV1h6VkMxVXhBbXJrNXBnY0pxZnpRQ0VBM1o2NDVCQkQwcllTSWgwWHJG?=
 =?utf-8?B?MUlIR0h2MHBBRyt0QkZOR0VkMnorT2RIdnFRcnBqbWxBNENBelhXQldRSEF0?=
 =?utf-8?B?TEpMcUYvU2w5TFpHMEROTzFBV3duUXBETklHMkRva05iQWpLM1oxZzdhUDQ5?=
 =?utf-8?B?eFhNcmx1L3U4Uld5a0xZNmE2bW1EVkJML05UMVlPbVgwMVRPT0lZSnY3ZTBp?=
 =?utf-8?B?eTB2aXYzTDYxbFRqUUh4MURoQmNmQmxra0g1WDJ0SGthcEdtZzlOQ3NjenJy?=
 =?utf-8?B?Tk1sYzcyTjJDdndtVlRjRmN5cHdwaXk1aEp4aFNSNEo4MFRRdVpFZk4vS1JK?=
 =?utf-8?B?ZGxwcXdFMnhZTUlsY3o3NGdqNXNHTnlDNk9mQk1yaktsQkQvYTJBWjg4SGhP?=
 =?utf-8?B?bWhnRnJiRndXWXkzVFF5Z3l5TmRZZHVCTWVoRWc5dG4zUDJTaTVjRnpTSDhB?=
 =?utf-8?B?Tzg5dFUrR1lyMVdDRUdvc2U2MUkxOFRyaFp1RHVyQmNCY004eEhvRk1reDVt?=
 =?utf-8?B?bFJLSTkzSFV6K001RnRlUTBseFZLSERsTjhNQXJmUmFrc25OVU1pZENkRXhn?=
 =?utf-8?B?bDdscXREZzlwbWd0QTNoRWFEU1RxOXJUZEVqQ05vOXZFZ1RhWUFRQWdlSHl0?=
 =?utf-8?B?U3JxdVU5MGFSazVJNklhNnNPQ2tqTHlNYmVFTEMxYW5FQUJSR3preHNEWDRv?=
 =?utf-8?B?ZzA0QlJnMGxqOXV5WE1XMHJxSkZJR3JMS215cWhvcHIrRytUelVmeEwrK0U3?=
 =?utf-8?B?c1BOSzdVOVpFUmJZOW56QUIvODd6N0QrU2FLUWRjRU53VDVtcEEweHY4bm9J?=
 =?utf-8?B?TjNoejJMQ3BoS01uT0sySUk1WnppSGFBVjloTUU4Qzc4cEVsckN5VElkYXo3?=
 =?utf-8?B?UUxHeVNMZDcrY29zRVZyb1ZXTVVxNERCdkhTdHVKaXVZTTJnK1NRWXpBalNJ?=
 =?utf-8?B?S0lOZUVsNElVV2N1d3h0UGJCbGdLd21UL3BMTk5KRUJtZ3h3bTNwWjVZRzcz?=
 =?utf-8?B?U0crbmZ2Rmx6dGM3bVJPejJXTDdUNUNwak4yVUZ0Vm5mME9HeklTd0lyQU4r?=
 =?utf-8?B?bkljWGU0N0hVZllXbDhYdFl3MnZqM0praHk3WEhac3pIRDVENnZFRlVsRzd4?=
 =?utf-8?B?UkYrQnk2YjZXT010cnhrbVA2L3pPelNwZ3FFS01nNFk4QzQxSFV3QW5LRVQr?=
 =?utf-8?B?QmliaUZNTU5WRDhWNDFzRzlhOTNjMkZ0K0tnVHptT1ZoMHhwL3Z5TS81amYv?=
 =?utf-8?B?d01VUlZwaTN1K3JiM0ZaUnMyTEgrbXFpV1lYOVpLNmVPVllQZmJXbUk2YlJ6?=
 =?utf-8?B?ZzMrNzdhSEJtVWdDNk5pbkZRcU1BZ2JqZGxUVS8yYUJDT2g1WHBZcDhFL3Fn?=
 =?utf-8?B?S0JVZU90ZE1TTXJ3TTlsbU4rZHA1TzFQNU5IQ2lTcmlaWTlKeVFrQ0VxdSs1?=
 =?utf-8?B?MTFUUmJqWnN0dlFVQkhtalp5Nmw3WGtJMVdZRFViWnJUa3FCZzA0bExqRzVX?=
 =?utf-8?B?bjdZeiszNkRXTzBnSndQTFpRSUlQMk5oMkErbHNyOWQwUEZXZ2VOcTA0TlZl?=
 =?utf-8?B?YTJLWnkvbVFaYUZCT0E1NXM0STdDWmJQTVQ1Z3p5aGdYMlp6VUQreFl3ZXU5?=
 =?utf-8?B?VnorcVNSS2JzRnQySmdKTjNubmRCbjZzazNHbUxiTVU5WkFjZ2NRUEwyYzdm?=
 =?utf-8?B?R0RRRjlTQVlURGhVNWEvVlhkMDdtN0VaMVlLVncwSlFwdHc2d3ZXbWtPUlJY?=
 =?utf-8?B?a2d0aXdIWkM2b0xEYjkrSkQ0dzZjQ0tpdEZ6MmVSdU1HSUUyNDRiTEl4bU1H?=
 =?utf-8?B?ZGZoWUFkMEVmSFV0Yzc1TFJpai9WNENXa01ldkFTVVcvT0VaeHF2bjdYeU45?=
 =?utf-8?B?ZzZmRDdqY2thTEk4QmliWkJheXRSRGg5bXZpUWU4anN0cmtxZ1RaemhjWHZP?=
 =?utf-8?B?VjV0cTl0WGFialV3YUFRUlRiRXNGRmIwVVFaditYY05yY3hIdGV2QkJ6ekxk?=
 =?utf-8?B?OGQzekQ3bzd0U0pqYWpPMlBnZ3hsWTVtWkVSWnY4dzMyN2lPYmV4VVN4cHdr?=
 =?utf-8?Q?x/Ubs902ALdl6mHY6xzfF5Aje?=
X-OriginatorOrg: amd.com
X-MS-Exchange-CrossTenant-Network-Message-Id: bc94b235-ca50-481d-23c7-08daef51d373
X-MS-Exchange-CrossTenant-AuthSource: CO6PR12MB5427.namprd12.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 05 Jan 2023 19:19:54.6992
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: mzJBthEVMus+ig4vzPoqh8z8/WXAYCy+LlQ0OZAclavMJJl9192350REhjF1QcAdDE1BIc4pIuq/7Rkg92i6hA==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA0PR12MB8303
X-Spam-Status: No, score=-5.0 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,NICE_REPLY_A,RCVD_IN_DNSWL_NONE,
        RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_PASS autolearn=ham
        autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 12/16/22 05:23, Yi Yang wrote:
> Smatch report warning as follows:
> 
> Line 53679: drivers/gpu/drm/amd/display/dc/core/dc_stream.c:402
> dc_stream_set_cursor_position() warn: variable dereferenced before
> check 'stream'
> 
> The value of 'dc' has been assigned after check whether 'stream' is
> NULL. Fix it by remove redundant assignment.
> 
> Signed-off-by: Yi Yang <yiyang13@huawei.com>

If this didn't blow up until now we might not even need
the NULL check below, but either way this is correct and

Reviewed-by: Harry Wentland <harry.wentland@amd.com>

Harry

> ---
>  drivers/gpu/drm/amd/display/dc/core/dc_stream.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
> index 20e534f73513..78d31bb875d1 100644
> --- a/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
> +++ b/drivers/gpu/drm/amd/display/dc/core/dc_stream.c
> @@ -408,7 +408,7 @@ bool dc_stream_set_cursor_position(
>  	struct dc_stream_state *stream,
>  	const struct dc_cursor_position *position)
>  {
> -	struct dc  *dc = stream->ctx->dc;
> +	struct dc *dc;
>  	bool reset_idle_optimizations = false;
>  
>  	if (NULL == stream) {