[Intel-gfx] [PATCH v3 1/2] PCI / PM: Add needs_resume flag to avoid suspend complete optimization

[Rafael J. Wysocki]

On Friday, April 28, 2017 11:33:02 PM Rafael J. Wysocki wrote:
> On Friday, April 28, 2017 05:16:02 PM Imre Deak wrote:
> > Some drivers - like i915 - may not support the system suspend direct
> > complete optimization due to differences in their runtime and system
> > suspend sequence. Add a flag that when set resumes the device before
> > calling the driver's system suspend handlers which effectively disables
> > the optimization.
> > 
> > Needed by the next patch fixing suspend/resume on i915.
> > 
> > Suggested by Rafael.
> > 
> > Cc: Rafael J. Wysocki <rafael.j.wysocki at intel.com>
> > Cc: Bjorn Helgaas <bhelgaas at google.com>
> > Cc: linux-pci at vger.kernel.org
> > Cc: stable at vger.kernel.org
> > Signed-off-by: Imre Deak <imre.deak at intel.com>
> 
> Acked-by: Rafael J. Wysocki <rafael.j.wysocki at intel.com>
> 
> The reason why the opt-out flag was not added on day one was because we were
> not sure whether or not it would be necessary at all.
> 
> Quite evidently, it is needed.

But that said, it actually can be implemented as a flag in dev_flags too, say
PCI_DEV_FLAGS_NEEDS_RESUME, in analogy with PCI_DEV_FLAGS_NO_D3 that's
already there.

The struct size would not need to grow then which I guess would be better?

Thanks,
Rafael