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: <d2828d36-275e-60d7-782e-2bff265bae0b@amd.com>
Date:   Sat, 9 Jul 2022 16:42:01 +0530
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.9.1
Subject: Re: [PATCH 3/3] ASoC: amd: fix for variable set but not used warning
Content-Language: en-US
To:     Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
        broonie@kernel.org, alsa-devel@alsa-project.org
Cc:     amadeuszx.slawinski@linux.intel.com, Basavaraj.Hiregoudar@amd.com,
        Sunil-kumar.Dommati@amd.com, zhuning@everest-semi.com,
        kernel test robot <lkp@intel.com>,
        Liam Girdwood <lgirdwood@gmail.com>,
        Jaroslav Kysela <perex@perex.cz>,
        Takashi Iwai <tiwai@suse.com>,
        open list <linux-kernel@vger.kernel.org>
References: <20220707132613.3150931-1-Vijendar.Mukunda@amd.com>
 <20220707132613.3150931-3-Vijendar.Mukunda@amd.com>
 <e2eab942-f122-7e37-e3a3-c8a1e153c91b@wanadoo.fr>
From:   "Mukunda,Vijendar" <vijendar.mukunda@amd.com>
In-Reply-To: <e2eab942-f122-7e37-e3a3-c8a1e153c91b@wanadoo.fr>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?ZnZpOXlyNHNITjRiOTBIQi9IYmJZb0EzT3laS09OTGkwZTAxTDhuYXN2SFJM?=
 =?utf-8?B?bktIUUEwTnpvMS8zWkxmWFdjWjg5UmZSbTlvOGhLVVVCM0lTaEJUSDVWMXh5?=
 =?utf-8?B?MFFsWlFja29KdHEvUVJ6Rmt2eVh5a1VXTFJWRHh6TU1tRjFQdUx2aVFkMU9y?=
 =?utf-8?B?UXFSSDdSY1h2VlJ6MHhHVWRJT0g5RCtieFg1Nnh5V2k2SXNJOE5FZkk2blZk?=
 =?utf-8?B?U0tGQTl3MjFnVldFbCtZdFlFcEpwUmRBNyt1RDFCQ3VIejJmOGhQWGJENUc4?=
 =?utf-8?B?Zm5reThsQTRyeDFnSCs4Yi9zd0JUcDBEc3lPZXpvdms0TUY0UG5DcDc4dnlx?=
 =?utf-8?B?QmhmZGxtZW4weDdLM0FseGhCaHQydlBiakkwK1lYWnJWZHBRU2hoSkpwcHlQ?=
 =?utf-8?B?QW9wNkcwLzQ4MUtsWUQvZEpsVHBsaU5Pb295M0szTFBYeWcwcDdIQnN3aFRo?=
 =?utf-8?B?Y3NsUDl6VHZpemtFRC9iUlIybzhlaXVKS1BWTHJhN3QzTm5MUTFUQmoycEJJ?=
 =?utf-8?B?ei9ZdGs5Y2lZbmVtUGliZmVMTTRRWlFPaU1tYXNMbC9hVHRHN094NWE1cy9K?=
 =?utf-8?B?c3RCdmloamlGUUZ3Nmc0amptL1Z2aWRKYU52cE9OQjVxQ0V2R2hlNjVHV3kz?=
 =?utf-8?B?bHYwTEF1aWl1S1NZWDdGYmowa3QwSjNQNmtNYzJYYmxPZXYrVWpRTzkvU24z?=
 =?utf-8?B?WDBvMHNtaUZETEQrb1JkK0xYN2Mra3o1QWx5RUNrSlBLVTRzSXJlUEtPd0RE?=
 =?utf-8?B?UEhqaGxmNy9RQUlJSkNnUXJxM1RZUGhHTTRwSjJhRTN6Q3ptcjYxUFE4RFdr?=
 =?utf-8?B?RkF6Z0Q2NTlIOEpGRWMvSW9PSmh1WDJoSG9IWS93cGF3RUo5SWhDSjg5THp1?=
 =?utf-8?B?UXdwRjJTMk9iTTFGUXcrYnJMakhTNndqQzVUWUdnNlUyZ3dra3E2aHFpVzN5?=
 =?utf-8?B?b1pwSnJlQzhRaDNBektKRlhxdGNpVUx2SllSTE4xRkswQjdqa01MTmQyU0Nw?=
 =?utf-8?B?azRZMUpXeFU3L2toWXV1eHlRYnc0VFNEdi9aei9VNDZlRXF1RlM1SXhwWnJm?=
 =?utf-8?B?cmZGNUViQTdwYWt4Y2xBZTM4Yk5Ga0RPMnA3SHI3ZGFoRXhMcHgvS2xSRVkz?=
 =?utf-8?B?N21ha2RUR1FxM29EMU5hU0JYMVllMHU5MTNSK0VnMG5rRFdJSGVqVTBmVHVV?=
 =?utf-8?B?b2hiYk5qQmhBR2RaSitrTzhQNzJrdWFEWVdJM1Jvd2NQWDhpRzRnbHpHYlpK?=
 =?utf-8?B?MnJDRDFCZHJsdGpKK0h5MUtFd0NCMk96M091QUp1cVF4Y1RMdTdnYTQ3ZTRO?=
 =?utf-8?B?K3gwTGUycWRBRkdtTk9YVzhvTnkvWStpaTZXVFlCbzhodXBOYUZjVVBPRi9J?=
 =?utf-8?B?OVN1Wkt0Y2R0NHNhamQwaFJlOEhLN3BaL2pVaWl4L25vUUJVOTdubDV6V1NC?=
 =?utf-8?B?TEYrcVR6Y3p4cThlYkFoUU1GdlJVUjgyWTQwR0dDVkk3VnJJdUs3ZnB3blJ1?=
 =?utf-8?B?VFlid1Y4YWpXNHl4QWpPSU1IdzdiWGs4UHp0dld0enk3RUR4MEFiZmd1NG53?=
 =?utf-8?B?dnlCNk9pN1UzdW5wWTg4R043elRWdG5tUVpVQVhwN25NbHlGaEQvcUxHalJk?=
 =?utf-8?B?d1lFNGlPYVNHNUZUY1lMVk1yZnNJZTRrRGpNS3BveTZFLzdXcTU1MnVReWZs?=
 =?utf-8?B?UlU2dTBqRllFejRRNHZaMDFtNHRPZDZ1eGhadU9UaXZKSVZIK3R0RTNPNjk1?=
 =?utf-8?B?UEJ5Z3RMRHFaRjNKQzVlMTNyb3hYdFNTUzdrY1JtUWJvMjlsYXFaR0FPLzl6?=
 =?utf-8?B?ZVovYWRHM0x6WU8vWm1Nb0FNQW8wbGpmNmxJK3lZK0o3RzJROHY4UnNEV0ds?=
 =?utf-8?B?Q0hHdFAybnEwdUgvWXRUN29RbEtqMzRHMVkyV1YzbXdKNWl4ODVVQ1B4R0U3?=
 =?utf-8?B?OHhXUTB6NEx3Y05XMHlnZUI3WjZuQ0xIYlF2MzhkMS9OYzFpM216bVF3VEJa?=
 =?utf-8?B?RGxYZzlHU2p1aWhsR2lPNGY5L0lPYUpRM0wrL0NUK2VtTmpxdUMxay9ONWJB?=
 =?utf-8?B?UGVrVGs1Rzl5Ykx2dWtlSWdpazNrbkk1YW1zdUx3dVk5c09aN2lZSE9COTVF?=
 =?utf-8?Q?2RYjqpOtpSRmueChyZN8vwptr?=
X-OriginatorOrg: amd.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 28c9ce6a-1e1a-4ab6-c847-08da619b868f
X-MS-Exchange-CrossTenant-AuthSource: DM6PR12MB4123.namprd12.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 09 Jul 2022 11:09:43.4866
 (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: 5lH90vxS6UUDJ330n2X2SVgS1DURjVHPSfk0XAmt/QPgUMhwlfa+bXC5eKYPPYRuA4017ohELLfjXaFyUjkDpA==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW3PR12MB4393
X-Spam-Status: No, score=-2.1 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,T_SCC_BODY_TEXT_LINE
        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 7/9/22 1:03 PM, Christophe JAILLET wrote:
> Le 07/07/2022 à 15:26, Vijendar Mukunda a écrit :
>> Fix below kernel warning.
>>>>> sound/soc/amd/acp-es8336.c:200:13: warning: variable 'ret' set but
>>>>> not used [-Wunused-but-set-variable]
>>
> 
> Hi,
> this patch, looks odd to me.
> 
> 
>> Signed-off-by: Vijendar Mukunda <Vijendar.Mukunda@amd.com>
>> Reported-by: kernel test robot <lkp@intel.com>
>> ---
>>   sound/soc/amd/acp-es8336.c | 3 +++
>>   1 file changed, 3 insertions(+)
>>
>> diff --git a/sound/soc/amd/acp-es8336.c b/sound/soc/amd/acp-es8336.c
>> index 90f4e5809c72..e1479ae684e9 100644
>> --- a/sound/soc/amd/acp-es8336.c
>> +++ b/sound/soc/amd/acp-es8336.c
>> @@ -206,6 +206,8 @@ static int st_es8336_late_probe(struct
>> snd_soc_card *card)
>>           dev_err(card->dev, "can not find codec dev\n");
> 
> The next devm_acpi_dev_add_driver_gpios() will fail, should we return
> immediately?
> 
>>         ret = devm_acpi_dev_add_driver_gpios(codec_dev,
>> acpi_es8336_gpios);
>> +    if (ret)
>> +        dev_warn(card->dev, "Failed to add driver gpios\n");
> 
> Should we return immediately?
As it required to support Machine driver differed probe , we shouldn't
return immediately.
We are checking gpiod_get_optional() return status. If still error is
reported, then return is invoked after checking whether return error
code is -EPROBE_DEFER.

We found similar implementation in other platforms machine driver code
as well.

>>         gpio_pa = gpiod_get_optional(codec_dev, "pa-enable",
>> GPIOD_OUT_LOW);
>>       if (IS_ERR(gpio_pa)) {
>> @@ -213,6 +215,7 @@ static int st_es8336_late_probe(struct
>> snd_soc_card *card)
>>                       "could not get pa-enable GPIO\n");
>>           gpiod_put(gpio_pa);
>>           put_device(codec_dev);
>> +        return ret;
> 
> Here, we return 'ret' which is what is returned by
> devm_acpi_dev_add_driver_gpios(). So there doesn't seem to be a link
> with this block which checks for gpiod_get_optional() errors.
> 
> Moreover, returning an error for something that is optional
> (gpiod_get_optional()) looks strange.
> 
> Finally, should an error be returned, maybe PTR_ERR(gpio_pa) would be
> better here.

Machine driver deferred probing should be supported.
err code PTR_ERR(gpio_pa) is compared with -EPROBE_DIFFER and same err
returned from dev_err_probe() API.

same code can also be modified as below

if (IS_ERR(gpio_pa)) {
	gpiod_put(gpio_pa);
	put_device(codec_dev);
	return dev_err_probe(card->dev, PTR_ERR(gpio_pa),
			    "could not get pa-enable GPIO\n");		

}


> 
> 
> Just my 2c.
> 
> CJ
> 
>>       }
>>       return 0;
>>   }
>