On Tue, Mar 24, 2020 at 07:26:35AM +0100, Greg Kroah-Hartman wrote: > On Mon, Mar 23, 2020 at 09:55:43PM +0200, Andy Shevchenko wrote: > > The ACPI companion of the device has to be set for USB interfaces > > in order to read and attach the properties described in the ACPI table. > > Use ACPI_COMPANION_SET macro to set this. > > > > Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> > > --- > > drivers/usb/core/message.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c > > index 5adf489428aa..d5f834f16993 100644 > > --- a/drivers/usb/core/message.c > > +++ b/drivers/usb/core/message.c > > @@ -5,6 +5,7 @@ > > * Released under the GPLv2 only. > > */ > > > > +#include <linux/acpi.h> > > #include <linux/pci.h> /* for scatterlist macros */ > > #include <linux/usb.h> > > #include <linux/module.h> > > @@ -1941,6 +1942,7 @@ int usb_set_configuration(struct usb_device *dev, int configuration) > > intf->dev.of_node = usb_of_get_interface_node(dev, > > configuration, ifnum); > > } > > + ACPI_COMPANION_SET(&intf->dev, ACPI_COMPANION(&dev->dev)); > > intf->dev.driver = NULL; > > intf->dev.bus = &usb_bus_type; > > intf->dev.type = &usb_if_device_type; > > And what does this "fix"? It links the firmware node of physical USB device to USB interface. Otherwise it will be no firmware nodes under a corresponding folder. It mimics what is done for OF in couple of lines above. > Is this a new feature, what isn't working today without this change? Yes, it is a new feature. I can't tell it fixes anything, because no complains so far. I doubt it previously works. > And if it is a fix, should it be backported to older kernels, how far? No, no need for that. Usually I put Fixes tag when I would like change to be considered for backporting. I'll probably update the commit message to clarify all this. Would it be enough? -- With Best Regards, Andy Shevchenko
