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SubjectRe: [PATCH] bcma: Replace mdelay with usleep_range in bcma_pmu_resources_init
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On 2018/1/27 0:26, Larry Finger wrote:
> On 01/26/2018 03:13 AM, Jia-Ju Bai wrote:
>> After checking all possible call chains to bcma_pmu_resources_init()
>> here,
>> my tool finds that this function is never called in atomic context,
>> namely never in an interrupt handler or holding a spinlock.
>> Thus mdelay can be replaced with usleep_range to avoid busy wait.
>>
>> This is found by a static analysis tool named DCNS written by myself.
>>
>> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
>> ---
>> drivers/bcma/driver_chipcommon_pmu.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/bcma/driver_chipcommon_pmu.c
>> b/drivers/bcma/driver_chipcommon_pmu.c
>> index f1eb4d3..478948c 100644
>> --- a/drivers/bcma/driver_chipcommon_pmu.c
>> +++ b/drivers/bcma/driver_chipcommon_pmu.c
>> @@ -203,7 +203,7 @@ static void bcma_pmu_resources_init(struct
>> bcma_drv_cc *cc)
>> * Add some delay; allow resources to come up and settle.
>> * Delay is required for SoC (early init).
>> */
>> - mdelay(2);
>> + usleep_range(1500, 2000);
>
> I have no idea how critical this delay might be, but it would be safer
> to never make the sleep be shorter than the original delay. Using
> (2000, 2500) would be a better choice of arguments for usleep_range().

Okay, I have used usleep_range(2000, 2500) and sent patch v2.


Thanks,
Jia-Ju Bai

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