Re: [PATCH] PCI: export pci_restore_msi_state()

[linas@austin.ibm.com (Linas Vepstas)]

On Thu, Nov 08, 2007 at 07:21:01PM -0600, Wen Xiong wrote:
> Hi Linas,
> 
> I saw you have submitted several patches to support pci-express network 
> adapters EEH. But looks only this patch fixed something in linux kernel 
> code.

And its an old patch, submitted long ago ... I've resubmitted, because
it seems that its the best/most correct thing to do.

> Do you mean I can test EEH callback functions in device driver after I 
> apply  this patch in the kernel?

Yes, please.  Note, however, I was never able to make the pci-e 
version of the e1000 work. It comes up, generates interrupts, and
registeres are readable and writeable. But it behvaes as if the PHY 
is turned off -- no network traffic goes thorugh. (I tried turning
PHY on explicitly; that didn't help). So there is still something 
wrong somewhere, probably in the e1000 deice driver. I'm guessing
the pci-e to pci-x bridge chip on that card is not quite resetting
the card completely.

> Do you do "pci_save_msi_state" somewhere in the kernel? Or you suggest to 
> do "pci_save_msi_state" and "pci_restore_msi_state" in each device driver?

There is no "save state", the msi state can't be saved. The MSI regs
are write-only, and they are controlled by firmware. The restore_state
function is the only one you need.

--linas