Re: [PATCH] bcma: Replace mdelay with usleep_range in bcma_pmu_resources_init

[Jia-Ju Bai]

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@xxxxxxxxx>
> > ---
> >   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