creating PCI-related sysfs entries

[Linas Vepstas]

On Thu, Feb 02, 2006 at 12:39:02PM -0700, Grant Grundler was heard to remark:
> 
> My guess is error handling/containment can abstract at the "bus" level
> since we can't always guarantee "one device per slot" (think
> multifunction devices).

:-) Yes, testing with multi-function cards exposed bugs, but the
code should work fine with them.  In particular, the design allows
multi-function devices to "vote" how they want to be reset, with
the dumbest voter getting thier way.

The bus disconnect is reported to all functions on all affected
cards/slots. This allows all instances of a device driver to react
appropriately.  However, for card setup/init, typically, you 
want to have only one driver instance do that. You'll notice 
in the sym53cxx2 patch I just sent, there's a 

+       if (PCI_FUNC(pdev->devfn) == 0)
+               sym_reset_scsi_bus(np, 0);

so that the other instances don't fall over each other reseting.
There's similar code in the e100 e1000 and ixgb drivers; I tested 
multi-function versions of these. (not sure about ixgb).

> Yes, I agree don't have a better idea other than what I already 
> pointed out.

Hmm. well, I may have lost the thread of what that was. 

--linas