Re: [GIT PATCH] More PCI patches for 2.6.13

[Linus Torvalds]

On Sat, 10 Sep 2005, Alan Stern wrote:

> On Fri, 9 Sep 2005, Linus Torvalds wrote:
> > 
> > In other words, there's nothing you can or should do about it. Testing the 
> > return value is pointless. And thus adding a "must_check" is really really 
> > wrong: it might make people do
> > 
> > 	if (pci_set_power_state(pdev, 0))
> > 		return -ENODEV
> > 
> > which is actually actively the _wrong_ thing to do, and would just cause 
> > old revisions of the chip that might not support PM capabilities to no 
> > longer work.
> 
> Funny you should say this -- exactly that problem _did_ arise.  See
> 
> http://marc.theaimsgroup.com/?l=linux-pci&m=112621842604724&w=2
> 
> pci_enable_device_bars() would an error when trying to initialize 
> devices without PM support, because it started checking the return value
> from pci_set_power_state().

Case closed. 

Bogus warnings are a _bad_ thing. They cause people to write buggy code.

That drivers/pci/pci.c code should be simplified to not look at the error
return from pci_set_power_state() at all. Special-casing EIO is just
another bug waiting to happen.

			Linus
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