Re: [PATCH] libertas: fix CF firmware loading for some cards

[Dan Williams <dcbw@redhat.com>]

On Fri, 2009-01-23 at 18:01 +0100, Michael Buesch wrote:
> On Friday 23 January 2009 17:55:33 Dan Williams wrote:
> > if_cs_poll_while_fw_download() returned the number of iterations
> > remaining on success, which in turn got returned as the value from
> > if_cs_prog_real() and if_cs_prog_helper().  But since if_cs_probe()
> > interprets non-zero return values from firmware load functions as an
> > error, this sometimes caused spurious firmware load failures.
> > 
> > Signed-off-by: Dan Williams <dcbw@redhat.com>
> > ---
> > 
> > diff --git a/drivers/net/wireless/libertas/if_cs.c b/drivers/net/wireless/libertas/if_cs.c
> > index 842a08d..8f8934a 100644
> > --- a/drivers/net/wireless/libertas/if_cs.c
> > +++ b/drivers/net/wireless/libertas/if_cs.c
> > @@ -151,7 +151,7 @@ static int if_cs_poll_while_fw_download(struct if_cs_card *card, uint addr, u8 r
> >  	for (i = 0; i < 100000; i++) {
> >  		u8 val = if_cs_read8(card, addr);
> >  		if (val == reg)
> > -			return i;
> > +			return 0;
> >  		udelay(5);
> >  	}
> >  	return -ETIME;
> 
> This is an incredibly expensive loop, btw. Even for init it's really painful to
> hog the CPU for more than half a second. Especially on UP.
> Any chance for msleep()?

Could be, Holger did the initial patch and I'm not sure if the udelay
was intentional.  Note that this happens at PCMCIA/CF hardware probe
time (if that has any constraints that might apply here).

dan