Re: [PATCH 2/4] i2c-i801: Fallback to polling if request_irq() fails

[Jean Delvare <jdelvare-l3A5Bk7waGM@public.gmane.org>]

Hi Wolfram,

Thanks for the quick review, very appreciated.

On Tue, 11 Nov 2014 11:57:34 +0100, Wolfram Sang wrote:
> On Mon, Nov 10, 2014 at 10:31:04PM +0100, Jean Delvare wrote:
> > The i2c-i801 driver can work without interrupts, so there is no reason
> > to make a request_irq failure fatal. Instead we can simply fallback
> > to polling.
> > 
> > Signed-off-by: Jean Delvare <jdelvare-l3A5Bk7waGM@public.gmane.org>
> > Cc: Wolfram Sang <wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org>
> > ---
> >  drivers/i2c/busses/i2c-i801.c |    7 ++++---
> >  1 file changed, 4 insertions(+), 3 deletions(-)
> > 
> > --- linux-3.18-rc4.orig/drivers/i2c/busses/i2c-i801.c	2014-11-10 22:29:42.788955868 +0100
> > +++ linux-3.18-rc4/drivers/i2c/busses/i2c-i801.c	2014-11-10 22:29:44.416991298 +0100
> > @@ -1242,9 +1242,11 @@ static int i801_probe(struct pci_dev *de
> >  		if (err) {
> >  			dev_err(&dev->dev, "Failed to allocate irq %d: %d\n",
> >  				dev->irq, err);
> > -			goto exit_release;
> > +			priv->features &= ~FEATURE_IRQ;
> > +			dev_info(&dev->dev, "SMBus using polling\n");
> 
> Shouldn't this message also be printed for !FEATURE_IRQ? I'd think it
> should be moved to another place.

Good point, I'll rework that part of the code and resubmit.

> We can also deduce from the dev_err
> above that polling will be used, no?

Having to deduce things doesn't make my supporter's life easy. Given
the problems that have been reported by the i2c-i801 driver users
lately, I'd rather be verbose during initialization to make bug reports
easier to analyze.

> > +		} else {
> > +			dev_info(&dev->dev, "SMBus using PCI interrupt\n");
> >  		}
> > -		dev_info(&dev->dev, "SMBus using PCI Interrupt\n");
> >  	}
> >  
> >  	/* set up the sysfs linkage to our parent device */
> > @@ -1272,7 +1274,6 @@ static int i801_probe(struct pci_dev *de
> >  exit_free_irq:
> >  	if (priv->features & FEATURE_IRQ)
> >  		free_irq(dev->irq, priv);
> > -exit_release:
> >  	pci_release_region(dev, SMBBAR);
> >  exit:
> >  	kfree(priv);
> > 

-- 
Jean Delvare
SUSE L3 Support