Re: [PATCH] PCI: add quirk for 3ware 9650SE controller

[Jiri Kosina <jkosina@suse.cz>]

On Fri, 6 Sep 2013, Bjorn Helgaas wrote:

> >> >> > Commit d5dea7d95 ("PCI: msi: Disable msi interrupts when we initialize a
> >> >> > pci device") makes MSIs be forcibly disabled at boot time.
> >> >> >
> >> >> > It turns out that this breaks 3ware controller -- if MSIs are disabled
> >> >> > during PCI discovery of this controller, the device doesn't work properly
> >> >> > (it doesn't respond to any commands that are being sent to it after
> >> >> > initialization).
> 
> Is there a bug report for this issue?  

Yes, but unfortunately only in our internal bugzilla.

> It's nice to have a pointer to, e.g., a bugzilla.kernel.org bug report 
> with info such as dmesg logs, lspci output, etc., for future reference.  

It's a customer-reported issue, so I am gathering permission to make this 
information public (I don't think that'll be an issue).

I'll send up a followup afterwards.

> Maybe somebody will figure out a more generic change that could make 
> this quirk unnecessary, and details will help in figuring that out.
> 
> I assume the actual PCI discovery done in the PCI core works fine;
> it's just that the driver doesn't work if MSIs are disabled on the
> device.  If that's the case, can this be fixed by some driver change?
> Maybe the driver needs to enable MSI before it sends commands to the
> device?

I have tried it, but it still doesn't work. It seems like the device 
initialization is not finalized properly with MISs disabled; meaning the 
device is there (discovery has completed), but it "just doesn't work".

> Any description of what this failure looks like to a user?  How can a 
> user or a distro connect a symptom (driver timeout, console message, or 
> whatever) to this patch?

Will be hopefully part of the dmesg I will be providing later ... 
basically any commands sent to it time out.

Thanks,

-- 
Jiri Kosina
SUSE Labs