Re: [PATCH v2] b43: Replace mdelay with usleep_range in b43_radio_2057_init_post

[Jia-Ju Bai]

On 2018/1/9 16:35, Greg KH wrote:
> On Tue, Jan 09, 2018 at 09:40:06AM +0800, Jia-Ju Bai wrote:
> > b43_radio_2057_init_post is not called in an interrupt handler
> > nor holding a spinlock.
> > The function mdelay in it can be replaced with usleep_range,
> > to reduce busy wait.
> >
> > Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>
> > ---
> > v2:
> > * Replace mdelay with usleep_range, instead of msleep in v1.
> >    Thank Larry for good advice.
> > ---
> >   drivers/net/wireless/broadcom/b43/phy_n.c |    2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/net/wireless/broadcom/b43/phy_n.c b/drivers/net/wireless/broadcom/b43/phy_n.c
> > index a5557d7..f2a2f41 100644
> > --- a/drivers/net/wireless/broadcom/b43/phy_n.c
> > +++ b/drivers/net/wireless/broadcom/b43/phy_n.c
> > @@ -1031,7 +1031,7 @@ static void b43_radio_2057_init_post(struct b43_wldev *dev)
> >   
> >   	b43_radio_set(dev, R2057_RFPLL_MISC_CAL_RESETN, 0x78);
> >   	b43_radio_set(dev, R2057_XTAL_CONFIG2, 0x80);
> > -	mdelay(2);
> > +	usleep_range(2000, 3000);
> Where did 3000 come from?  Are you sure about that?

I am not very sure, and I use it according to Larry's message:

> I had negative comments on one of those due to the possibility of
> msleep(2) extending as long as 20 msec. Until the author, or someone
> else, can test that this is OK, then the mdelay(2) can only be
> replaced with usleep_range(2000, 3000).

Thanks,
Jia-Ju Bai