Hi!
I'm sorry, I'm not savvy enough to know what to do with this (I know
basics on how to code and compile, but I'm no dev). Could someone
guide me through it?
I gather this patch needs to be applied to some kernel module code
which needs to be compiled and reloaded into my current kernel,
right?
Sorry to let you down...
Cheers,
Pierre.
Le mardi 11 octobre 2016, 11:18:28 NZDT Alan Stern a écrit :
> On Sat, 8 Oct 2016, Lukas Wunner wrote:
> > The PCI core already calls pm_runtime_get_sync() before invoking
the
> > ->probe hook of a driver (see local_pci_probe()). Drivers need
to
> > explicitly release a runtime ref to allow their device to
suspend.
> >
> > For xhci-pci, this seems to happen in usb_hcd_pci_probe():
> > if (pci_dev_run_wake(dev))
> >
> > pm_runtime_put_noidle(&dev->dev);
> >
> > So you could either modify the if-condition if you want to
change the
> > behaviour for XHCI devices only, or if you want to change it in
general,
> >
> > add something like this to pci_dev_run_wake():
> > /* PME capable in principle, but not from the intended sleep
state */
> > if (dev->pme_support && !pci_pme_capable(dev,
pci_target_state(dev)))
> >
> > return false;
> >
> > I've briefly looked over the callers of pci_dev_run_wake() and
the above
> > seems safe but you should double-check them.
>
> That seems like a good suggestion. The patch is below; Pierre,
can you
> test it? This should remove the need to set the USB autosuspend
module
> parameter to -1.
>
> Alan Stern
>
>
>
> Index: usb-4.x/drivers/pci/pci.c
>
===================================================================
> --- usb-4.x.orig/drivers/pci/pci.c
> +++ usb-4.x/drivers/pci/pci.c
> @@ -2064,6 +2064,10 @@ bool pci_dev_run_wake(struct pci_dev *de
> if (!dev->pme_support)
> return false;
>
> + /* PME-capable in principle, but not from the intended sleep
state */
> + if (!pci_pme_capable(dev, pci_target_state(dev)))
> + return false;
> +
> while (bus->parent) {
> struct pci_dev *bridge = bus->self;
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