Re: [PATCH] net: dsa: b53: Replace mdelay with msleep in b53_switch_reset_gpio

[Jia-Ju Bai]

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 <baijiaju1990@xxxxxxxxx>
> > ---
> >   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()?


Best wishes,
Jia-Ju Bai