On 04/11/2018 12:14 AM, Jia-Ju Bai wrote: > > > On 2018/4/11 13:30, Phil Reid wrote: >> On 11/04/2018 09:51, Jia-Ju Bai wrote: >>> b53_switch_reset_gpio() is never called in atomic context. >>> >>> The call chain ending up at b53_switch_reset_gpio() is: >>> [1] b53_switch_reset_gpio() <- b53_switch_reset() <- >>> b53_reset_switch() <- b53_setup() >>> >>> b53_switch_reset_gpio() is set as ".setup" in struct dsa_switch_ops. >>> This function is not called in atomic context. >>> >>> Despite never getting called from atomic context, >>> b53_switch_reset_gpio() >>> calls mdelay() to busily wait. >>> This is not necessary and can be replaced with msleep() to >>> avoid busy waiting. >>> >>> This is found by a static analysis tool named DCNS written by myself. >>> And I also manually check it. >>> >>> Signed-off-by: Jia-Ju Bai <baijiaju1...@gmail.com> >>> --- >>> drivers/net/dsa/b53/b53_common.c | 4 ++-- >>> 1 file changed, 2 insertions(+), 2 deletions(-) >>> >>> diff --git a/drivers/net/dsa/b53/b53_common.c >>> b/drivers/net/dsa/b53/b53_common.c >>> index 274f367..e070ff6 100644 >>> --- a/drivers/net/dsa/b53/b53_common.c >>> +++ b/drivers/net/dsa/b53/b53_common.c >>> @@ -597,10 +597,10 @@ static void b53_switch_reset_gpio(struct >>> b53_device *dev) >>> /* Reset sequence: RESET low(50ms)->high(20ms) >>> */ >>> gpio_set_value(gpio, 0); >>> - mdelay(50); >>> + msleep(50); >>> gpio_set_value(gpio, 1); >>> - mdelay(20); >>> + msleep(20); >>> dev->current_page = 0xff; >>> } >>> >> Would that also imply gpio_set_value could be gpio_set_value_cansleep? >> > > Yes, I think gpio_set_value_cansleep() is okay here? > Do I need to send a V2 patch to replace gpio_set_value()?
Yes, I would lump these two changes in the same patch since this is effectively about solving sleeping vs. non sleeping operations. Thanks! -- Florian
