Re: [PATCH] pci: fix kexec with power state D3

From: Rafael J. Wysocki
Date: Sun Mar 08 2009 - 06:29:19 EST


On Sunday 08 March 2009, Ingo Molnar wrote:
>
> * Rafael J. Wysocki <rjw@xxxxxxx> wrote:
>
> > On Sunday 08 March 2009, Yinghai Lu wrote:
> > >
> > > Impact: second kernel by kexec will have some pci devices working
> > >
> > > Found one system with 82575EB, in the kernel that is kexeced, probe igb
> > > failed with -2.
> > >
> > > it looks like the same behavior happened on forcedeth.
> > > try to check system_state to make sure if put it on D3
> >
> > This is not enough, because the PM code doesn't change
> > system_state and it uses pci_set_power_state too.
> >
> > > Jesse Brandeburg said that we should do that check in core
> > > code instead of every device driver.
> >
> > Well, I'm not really sure. The drivers are where the bug is.
>
> So Yinghai has now written a driver fix and a generic code fix
> as well and both are being rejected pointing to the other side?
>
> This really sucks for users (who'd be happy with any of the
> patches) and the disagreement needs to be resolved ASAP.

I hope you read my other comment (that you deleted from the reply)?

If we're going to fix this at the core level along the Yinghai's patch lines,
we'll have to introduce a few additional values for system_state and make
suspend and hibernation code use them.

Do you think it's worth the effort, given that only a couple of drivers have
been found to be affected so far?

Rafael
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