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Subject: Re: [PATCH] ARM/smp_twd: Cleanup the unnecessary cast
To:     "Russell King (Oracle)" <linux@armlinux.org.uk>
Cc:     linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
References: <20210811131512.940-1-tangbin@cmss.chinamobile.com>
 <20210811133121.GV22278@shell.armlinux.org.uk>
From:   tangbin <tangbin@cmss.chinamobile.com>
Message-ID: <54505b20-a9c6-9ade-dced-cb4c24df0770@cmss.chinamobile.com>
Date:   Wed, 11 Aug 2021 21:47:10 +0800
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Hi Russell:

On 2021/8/11 21:31, Russell King (Oracle) wrote:
> On Wed, Aug 11, 2021 at 09:15:12PM +0800, Tang Bin wrote:
>> It's not necessary to specify 'int' castingfor 'PTR_ERR(twd_clk)'.
>>
>> Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
>> ---
>>   arch/arm/kernel/smp_twd.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/arm/kernel/smp_twd.c b/arch/arm/kernel/smp_twd.c
>> index 9a14f721a..423e9079d 100644
>> --- a/arch/arm/kernel/smp_twd.c
>> +++ b/arch/arm/kernel/smp_twd.c
>> @@ -199,7 +199,7 @@ static void twd_get_clock(struct device_node *np)
>>   		twd_clk = clk_get_sys("smp_twd", NULL);
>>   
>>   	if (IS_ERR(twd_clk)) {
>> -		pr_err("smp_twd: clock not found %d\n", (int) PTR_ERR(twd_clk));
>> +		pr_err("smp_twd: clock not found %d\n", PTR_ERR(twd_clk));
> Sorry, NAK.
>
> This change _will_ produce a compiler warning. "%d" expects an argument
> of type "int", but PTR_ERR() returns a type of "long". Sorry, but the
> cast is entirely necessary.
>
> A better solution today would be to get rid of the PTR_ERR() entirely
> and use %pe, which will get us a textual description of the error when
> the appropriate kernel configuration option is enabled.
>
Got it, Thanks.
>