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Subject: Re: [PATCH] soc: imx8m: fix wrong return value check of
 of_clk_get_by_name()
To:     Alexander Stein <alexander.stein@ew.tq-group.com>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>
CC:     <shawnguo@kernel.org>, <s.hauer@pengutronix.de>,
        <kernel@pengutronix.de>, <festevam@gmail.com>, <linux-imx@nxp.com>,
        <xiaolei.wang@windriver.com>, <l.stach@pengutronix.de>
References: <20230104064136.1695102-1-yangyingliang@huawei.com>
 <1882509.eGJsNajkDb@steina-w>
From:   Yang Yingliang <yangyingliang@huawei.com>
Message-ID: <82ddb754-a0e5-efaf-6654-70a795ab8b81@huawei.com>
Date:   Wed, 4 Jan 2023 16:03:17 +0800
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On 2023/1/4 15:50, Alexander Stein wrote:
> Hi,
>
> Am Mittwoch, 4. Januar 2023, 07:41:36 CET schrieb Yang Yingliang:
>> of_clk_get_by_name() never returns NULL pointer, it will return
>> ERR_PTR() when it fails, so replace the check with IS_ERR().
>>
>> Fixes: 836fb30949d9 ("soc: imx8m: Enable OCOTP clock before reading the
>> register") Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
>> ---
>>   drivers/soc/imx/soc-imx8m.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/soc/imx/soc-imx8m.c b/drivers/soc/imx/soc-imx8m.c
>> index 28144c699b0c..32ed9dc88e45 100644
>> --- a/drivers/soc/imx/soc-imx8m.c
>> +++ b/drivers/soc/imx/soc-imx8m.c
>> @@ -66,8 +66,8 @@ static u32 __init imx8mq_soc_revision(void)
>>   	ocotp_base = of_iomap(np, 0);
>>   	WARN_ON(!ocotp_base);
>>   	clk = of_clk_get_by_name(np, NULL);
>> -	if (!clk) {
>> -		WARN_ON(!clk);
>> +	if (IS_ERR(clk)) {
> Nice catch. But wouldn't
>> if (WARN_ON(IS_ERR(clk)))
> be even better instead of doing the check twice?
Yes, it's better, I will send a new version.

Thanks,
Yang
>
> Best regards,
> Alexander
>
>> +		WARN_ON(IS_ERR(clk));
>>   		return 0;
>>   	}
>
>
>
> .