| Message ID | 20180730134838.9124-1-baijiaju1990@gmail.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
| Series | power: reset: piix4-poweroff: Replace mdelay() with msleep() and usleep_range() in piix4_poweroff() | expand |
Hi, On Mon, Jul 30, 2018 at 09:48:38PM +0800, Jia-Ju Bai wrote: > piix4_poweroff() is never called in atomic context. > It calls mdelay() to busily wait, which is not necessary. > mdelay() can be replaced with msleep() and usleep_range(). > > This is found by a static analysis tool named DCNS written by myself. > > Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> > --- This is a shutdown driver, so busy waiting is ok. -- Sebastian > drivers/power/reset/piix4-poweroff.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/power/reset/piix4-poweroff.c b/drivers/power/reset/piix4-poweroff.c > index 20ce3ff5e039..5d4c72992d2c 100644 > --- a/drivers/power/reset/piix4-poweroff.c > +++ b/drivers/power/reset/piix4-poweroff.c > @@ -47,7 +47,7 @@ static void piix4_poweroff(void) > io_offset + PIIX4_FUNC3IO_PMCNTRL); > > /* If the special cycle occurs too soon this doesn't work... */ > - mdelay(10); > + usleep_range(10000, 11000); > > /* > * The PIIX4 will enter the suspend state only after seeing a special > @@ -59,7 +59,7 @@ static void piix4_poweroff(void) > PIIX4_SUSPEND_MAGIC); > > /* Give the system some time to power down, then error */ > - mdelay(1000); > + msleep(1000); > pr_emerg("Unable to poweroff system\n"); > } > > -- > 2.17.0 >
diff --git a/drivers/power/reset/piix4-poweroff.c b/drivers/power/reset/piix4-poweroff.c index 20ce3ff5e039..5d4c72992d2c 100644 --- a/drivers/power/reset/piix4-poweroff.c +++ b/drivers/power/reset/piix4-poweroff.c @@ -47,7 +47,7 @@ static void piix4_poweroff(void) io_offset + PIIX4_FUNC3IO_PMCNTRL); /* If the special cycle occurs too soon this doesn't work... */ - mdelay(10); + usleep_range(10000, 11000); /* * The PIIX4 will enter the suspend state only after seeing a special @@ -59,7 +59,7 @@ static void piix4_poweroff(void) PIIX4_SUSPEND_MAGIC); /* Give the system some time to power down, then error */ - mdelay(1000); + msleep(1000); pr_emerg("Unable to poweroff system\n"); }
piix4_poweroff() is never called in atomic context. It calls mdelay() to busily wait, which is not necessary. mdelay() can be replaced with msleep() and usleep_range(). This is found by a static analysis tool named DCNS written by myself. Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> --- drivers/power/reset/piix4-poweroff.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)