On Wed, Nov 28, 2012 at 12:39:14PM -0500, Alan Stern wrote:
> On Sat, 17 Nov 2012, Lan Tianyu wrote:
> > --- a/drivers/usb/core/hub.c
> > +++ b/drivers/usb/core/hub.c
> > @@ -1546,6 +1546,25 @@ static int hub_configure(struct usb_hub *hub,
> > dev_err(hub->intfdev,
> > "couldn't create port%d device.\n", i + 1);
> >
> > + if (!hub_is_superspeed(hdev)) {
> > + for (i = 1; i <= hdev->maxchild; i++)
> > + if (hub->ports[i - 1]->connect_type
> > + == USB_PORT_CONNECT_TYPE_HARD_WIRED)
> > + hub->descriptor->u.hs.DeviceRemovable[i/8]
> > + |= 1 << (i%8);
> > + } else {
> > + u16 port_removable =
> > + le16_to_cpu(hub->descriptor->u.ss.DeviceRemovable);
> > +
> > + for (i = 1; i <= hdev->maxchild; i++)
> > + if (hub->ports[i - 1]->connect_type
> > + == USB_PORT_CONNECT_TYPE_HARD_WIRED)
> > + port_removable |= 1 << i;
> > +
> > + hub->descriptor->u.ss.DeviceRemovable =
> > + cpu_to_le16(port_removable);
> > + }
> > +
>
> You've got all this code here, and you added copies of the same thing
> to ehci-hcd and xhci-hcd. That's wasteful, and it also ignores the
> other HCDs.
>
> Instead, how about sticking the new code into a separate function:
>
> void hub_adjust_DeviceRemovable(struct usb_device *hdev,
> struct usb_hub_descriptor *desc);
>
> Call this new function here and at the appropriate place in
> hcd.c:rh_call_control(). Then no modifications would be needed in
> ehci-hcd or xhci-hcd.
So you would basically let EHCI and xHCI set the DeviceRemovable bits in
their hub descriptors and then have the USB core overwrite them? If a
userspace program like lsusb asks for the hub descriptors, would they
see the updated version, or the original version?
The shared code to overwrite the bits should probably print a warning if
the host and ACPI bits differ.
Sarah Sharp
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