Am Freitag, den 09.02.2018, 14:58 +0100 schrieb Ulf Hansson: > On 26 January 2018 at 09:38, Jia-Ju Bai <[email protected]> > wrote: > > After checking all possible call chains to genpd_dev_pm_detach() > > and > > genpd_dev_pm_attach() here, > > my tool finds that these functions are never called in atomic > > context, > > namely never in an interrupt handler or holding a spinlock. > > Thus mdelay can be replaced with msleep to avoid busy wait. > > > > This is found by a static analysis tool named DCNS written by > > myself. > > > > Signed-off-by: Jia-Ju Bai <[email protected]> > > --- > > drivers/base/power/domain.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/base/power/domain.c > > b/drivers/base/power/domain.c > > index 0c80bea..f84ac72 100644 > > --- a/drivers/base/power/domain.c > > +++ b/drivers/base/power/domain.c > > @@ -2144,7 +2144,7 @@ static void genpd_dev_pm_detach(struct device > > *dev, bool power_off) > > if (ret != -EAGAIN) > > break; > > > > - mdelay(i); > > + msleep(i); > > This looks like a nice improvement, however moving to msleep() makes > the call to cond_resched() below a bit superfluous. Perhaps remove > that as well.
At least for small values of i, msleep also has a high chance to overshoot the desired sleep by a lot. It would be better to convert them to usleep_range with an acceptable slack. Regards, Lucas > > cond_resched(); > > } > > > > @@ -2231,7 +2231,7 @@ int genpd_dev_pm_attach(struct device *dev) > > if (ret != -EAGAIN) > > break; > > > > - mdelay(i); > > + msleep(i); > > Ditto. > > > cond_resched(); > > } > > mutex_unlock(&gpd_list_lock); > > -- > > 1.7.9.5 > > > > Kind regards > Uffe
