[SeaBIOS] [PATCH] seabios: call pci_init_device on resume

Michael S. Tsirkin mst at redhat.com
Thu Dec 19 23:40:24 CET 2013

On Thu, Dec 19, 2013 at 11:32:03PM +0100, Laszlo Ersek wrote:
> On 12/19/13 23:16, Michael S. Tsirkin wrote:
> > I suspect we need to init more devices, but I need to look some
> > more into this. Basically whatever OS does not restore, we have to.
> I don't think that implication is necessarily true. Just because neither
> restores some device state currently doesn't imply the firmware should
> restore it. The OS is much better equipped to restore complex state;

If you look at my patch, there's nothing complex there.

> the
> firmware should only have to ensure that the OS gets a chance to run again.
> The Platform Init spec 1.2.1 says in Vol5, DXE and the S3
> Resume Boot Path,
>   The ACPI specification only requires the BIOS to restore chipset and
>   processor configuration. [...]

All of PIIX and Q35 is part if the chipset though.

> I'm not sure which part of the ACPI spec they refer to, and of course
> this statement may not be overly accurate either, but it does seem to
> limit the firmware's responsibility.
> Laszlo

Basically OSes are tested on real hardware. Whatever firmware for
real boards restores, OS-es won't restore so we have to.


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