[PATCH v2 2/2] [usb] add support for ACPI identification to xhci-platform

Greg KH
2014-11-05T22:05:03Z

On Wed, Nov 05, 2014 at 09:41:23PM +0100, Arnd Bergmann wrote:
> On Wednesday 05 November 2014 11:55:07 Greg KH wrote:
> > On Wed, Nov 05, 2014 at 01:44:43PM -0600, Mark Langsdorf wrote:
> > > On 11/05/2014 01:11 PM, Greg KH wrote:
> > > >On Wed, Nov 05, 2014 at 07:59:32AM -0600, Mark Langsdorf wrote:
> > > >>>> static struct platform_driver usb_xhci_driver = {
> > > >>>> .probe = xhci_plat_probe,
> > > >>>> .remove = xhci_plat_remove,
> > > >>>>@@ -294,6 +304,7 @@ static struct platform_driver usb_xhci_driver = {
> > > >>>> .name = "xhci-hcd",
> > > >>>> .pm = DEV_PM_OPS,
> > > >>>> .of_match_table = of_match_ptr(usb_xhci_of_match),
> > > >>>>+ .acpi_match_table = ACPI_PTR(usb_xhci_acpi_match),
> > > >>>
> > > >>>Shouldn't the reworked driver core code handle this differently with the
> > > >>>ability to handle either OF or ACPI in the same driver?
> > > >>
> > > >>I'm not sure I understand the question. With these changes, the driver
> > > >>handles both ACPI and DTB/OF. It's the same style of code as used
> > > >>in drivers/ata/plat-xgene.c, which also handles both ACPI and DTB/OF.
> > > >>Why do you think this code isn't correct?
> > > >
> > > >There is a new framework in the kernel that keeps a driver from having
> > > >to query both of and acpi to get the needed resources, it just does one
> > > >query and depending on the platform, everything "just works". Shouldn't
> > > >that be used here as well?
> > >
> > > Would you send me a pointer to a driver that's using this new
> > > framework? I can't find any references to it and all the other
> > > drivers that support ACPI and OF are doing it the way I'm doing
> > > it.
> >
> > See the email on lkml:
> > Subject: [PATCH v6 00/12] Add ACPI _DSD and unified device properties support
> >
> > for the latest patch series.
> >
>
> The _DSD approach is for devices that do not follow the ACPI specification
> but do have a DT binding. Those will work without the .acpi_match_table
> entry when the firmware uses the compatible value in the new properties.
>
> In this case, the device does have an official ACPI ID "PNP0D10", so we should
> use that for compatibility with other operating systems and with BIOS
> versions that provide the standard IDs.

Ah, ok, nevermind then, sorry for the noise, I wasn't aware of this.

greg k-h