[PATCH 3/3] rtc: stm32: use 32-bit cast for BIT() macro

Arnd Bergmann arnd at arndb.de
Fri Jan 13 08:48:49 PST 2017

On Fri, Jan 13, 2017 at 4:56 PM, Amelie DELAUNAY <amelie.delaunay at st.com> wrote:
> On 01/13/2017 04:32 PM, Arnd Bergmann wrote:
>> Using the ~ operator on a BIT() constant results in a large 'unsigned
>> long'
>> constant that won't fit into an 'unsigned int' function argument on 64-bit
>> architectures, resulting in a harmless build warning in x86 allmodconfig:
>> drivers/rtc/rtc-stm32.c: In function 'stm32_rtc_probe':
>> drivers/rtc/rtc-stm32.c:651:51: error: large integer implicitly truncated
>> to unsigned type [-Werror=overflow]
>>   regmap_update_bits(rtc->dbp, PWR_CR, PWR_CR_DBP, ~PWR_CR_DBP);
> I thought I would fix this warning by replacing all ~PWR_CR_DBP by 0,
> because the mask PWR_CR_DBP prevents other bits to be cleared.
> In this way, I avoid the ugly cast...

Good idea, much nicer than mine! Can you send that patch?


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