[PATCH v2] staging: comedi: resolve section mismatch in s626

Gerard Snitselaar dev at snitselaar.org
Mon Mar 19 22:46:49 UTC 2012

On Mon, Mar 19, 2012 at 09:43:25AM -0700, Gerard Snitselaar wrote:
> On Mon, Mar 19, 2012 at 09:31:03AM -0700, Greg KH wrote:
> > 
> > Ick, why is this loop even needed?  We are only here if the pci device
> > is present in the system so this shouldn't be needed at all, right?
> > 
> > Or is this a bit more complex than I am making it out to be?
> > 
> > greg k-h
> Most likely not. I will take a look at some of the other drivers in
> comedi and see how the attach code looks there. I believe the code
> section in hpdi_attach() was written by the same person. Unfortunately
> I don't have a device to actually play around and see what changes are
> doing.

I looked at this a bit more. It looks like they lose visibility to the
pci_dev structure.

   comedi_pci_auto_config()     pci_dev
      comedi_auto_config()      pci_dev->dev
         comedi_device_attach() ??
            driv->attach()      ?? <= iterate through pci devices.

Most of the examples I have looked at so far use for_each_pci_dev() to
find the device, and s626 shortcuts it a bit by directly making calls
to pci_get_subsys() with specific ids. They all verify they have the
right device by checking the bus and slot that are grabbed from the
pci_dev in comedi_pci_auto_config() and passed down.

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