On Mon, Dec 11, 2017 at 02:37:22PM +0530, Arvind Yadav wrote:
> Hi Dan,
>
>
> On Monday 11 December 2017 02:10 PM, Dan Carpenter wrote:
> > On Sun, Dec 10, 2017 at 08:10:26AM +0530, arvindY wrote:
> > >
> > > On Sunday 10 December 2017 07:22 AM, Dan Carpenter wrote:
> > > > On Sat, Dec 09, 2017 at 06:27:32PM +0100, Alexandre Belloni wrote:
> > > > > > > diff --git a/sound/soc/nuc900/nuc900-ac97.c b/sound/soc/nuc900/nuc900-ac97.c
> > > > > > > index 5e4fbd2d3479..71fce7c85c93 100644
> > > > > > > --- a/sound/soc/nuc900/nuc900-ac97.c
> > > > > > > +++ b/sound/soc/nuc900/nuc900-ac97.c
> > > > > > > @@ -345,11 +345,10 @@ static int nuc900_ac97_drvprobe(struct platform_device *pdev)
> > > > > > > goto out;
> > > > > > > }
> > > > > > > - nuc900_audio->irq_num = platform_get_irq(pdev, 0);
> > > > > > > - if (nuc900_audio->irq_num <= 0) {
> > > > > > > - ret = nuc900_audio->irq_num < 0 ? nuc900_audio->irq_num : -EBUSY;
> > > > > > > + ret = platform_get_irq(pdev, 0);
> > > > > > > + if (ret < 0)
> > > > > The <= 0 was ok, see:
> > > > > https://lkml.org/lkml/2017/11/18/41
> > > > >
> > > > Yeah, but is it ever going to return 0? That seems like a design error
> > > > and also really crap commenting if so
> > > yes, It can return 0 on sprac platform and If you see the return of
> > > platform_get_irq() 'return r ? r->start : -ENXIO;'. It should be
> > > 'return r && r->start? r->start : -ENXIO;'. We can not add checks here,
> > > Because There's a bunch of platforms in the kernel they still use IRQ0 as
> > > valid.
> > > I have separate mails where few maintainer ask me to add check for 0 and few
> > > not.
> > > Adding check for 0 will never harm.
> > What you're saying doesn't make sense.
> I am following a below link. Where they have point out irq 0 is not valid.
> https://lwn.net/Articles/470820/
That article is interesting and explains why this stuff is so messed up,
but I think my email is correct. No one is going to tell the kernel,
"There is an IRQ resource at 0, please store it in r->start. We can't
use that IRQ, it's only there to make the kernel crash when people call
platform_get_irq()! #geniusidea."
There are other IRQ functions like irq_of_parse_and_map() which do
return zero on error but platform_get_irq() pretty clearly returns
negative error codes.
regards,
dan carpenter
--
To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
