Messages in this thread |  | | | From | Rusty Russell <> | | Subject | Re: [PULL] virtio and lguest | | Date | Fri, 13 Jan 2012 12:59:19 +1030 |
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On Thu, 12 Jan 2012 16:29:14 -0800, Linus Torvalds <torvalds@linux-foundation.org> wrote: > On Wed, Jan 11, 2012 at 9:22 PM, Rusty Russell <rusty@rustcorp.com.au> wrote: > > > > Amit Shah (12): > > virtio: pci: switch to new PM API > > Hmm. Afaik, this is broken, or at least not complete. > > Sure, it switches to the new PM API, but it still does the PCI ops itself. > > It should not need to - the PCI layer will do the power state and > standard PCI device state saving. And setting the PCI_D3hot state when > shared interrupts can still happen at suspend time is just a bad idea. > > So I think you're doing extra work and introducing bugs by doing so - > the default PCI bus operations should already do all you do, just do > it better. And then you can use the SIMPLE_DEV_PM_OPS() to build the > dev_pm_ops structure and get all the normal cases right automatically. > > I don't know if there is any particularly good example of this, but > you can see some of the network drivers for examples of this. Notice > how they don't need to worry about PCI power states etc at all, they > just need to worry about the actual chip suspend/resume (and for a > network driver, you'd do the netif_device_detach/netif_device_attach > etc)
Ok, I'll confess complete ignorance, and wait for Amit to respond. I must admit that PM for virtual devices is not a personal priority...
Thanks, Rusty. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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