RE: [PATCH] xhci-pci: Enable runtime PM on Alder Lake-N PCH xHCI controller

From: Kao, Ben
Date: Thu Jul 14 2022 - 05:06:52 EST


> From: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>
> Sent: Tuesday, July 12, 2022 8:45 PM
> To: Kao, Ben <ben.kao@xxxxxxxxx>
> Cc: Nyman, Mathias <mathias.nyman@xxxxxxxxx>;
> mathias.nyman@xxxxxxxxxxxxxxx; linux-usb@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH] xhci-pci: Enable runtime PM on Alder Lake-N PCH xHCI
> controller
>
> On Tue, Jul 12, 2022 at 08:24:42PM +0800, Ben Kao wrote:
> > There are two Alder Lake-N xHCI host controllers with PCI IDs 0x464e
> > and 0x54ed, now we add the quirk to default enable runtime PM for
> > 0x54ed.
> >
> > Signed-off-by: Ben Kao <ben.kao@xxxxxxxxx>
> > ---
> > drivers/usb/host/xhci-pci.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
> > index dce6c0ec8d34..44486156bd5d 100644
> > --- a/drivers/usb/host/xhci-pci.c
> > +++ b/drivers/usb/host/xhci-pci.c
> > @@ -61,6 +61,7 @@
> > #define PCI_DEVICE_ID_INTEL_ALDER_LAKE_XHCI 0x461e
> > #define PCI_DEVICE_ID_INTEL_ALDER_LAKE_N_XHCI
> 0x464e
> > #define PCI_DEVICE_ID_INTEL_ALDER_LAKE_PCH_XHCI 0x51ed
> > +#define PCI_DEVICE_ID_INTEL_ALDER_LAKE_N_PCH_XHCI 0x54ed
>
> I think we ask this every time, but why don't we enable this for all devices
> and then only disable it for the tiny number that don't need it?
Got it, I will provide another patch to enable runtime PM by default for all
Intel devices if no one has concerns.

>
> Why do you all force us to add this for every new device created?
>
> thanks,
>
> greg k-h