On Fri, Sep 07, 2012 at 05:33:29PM +0800, Lan Tianyu wrote:
> On 2012/9/5 22:39, Alan Stern wrote:
> >On Wed, 5 Sep 2012, Lan Tianyu wrote:
> >
> >>This is copied from xhci_usb3_hub_descriptor().
> >>
> >>struct usb_hub_descriptor {
> >> __u8 bDescLength;
> >> __u8 bDescriptorType;
> >> __u8 bNbrPorts;
> >> __le16 wHubCharacteristics;
> >> __u8 bPwrOn2PwrGood;
> >> __u8 bHubContrCurrent;
> >>
> >> /* 2.0 and 3.0 hubs differ here */
> >> union {
> >> struct {
> >> /* add 1 bit for hub status change; round to bytes */
> >> __u8 DeviceRemovable[(USB_MAXCHILDREN + 1 + 7) / 8];
> >> __u8 PortPwrCtrlMask[(USB_MAXCHILDREN + 1 + 7) / 8];
> >> } __attribute__ ((packed)) hs;
> >>
> >> struct {
> >> __u8 bHubHdrDecLat;
> >> __u16 wHubDelay;
> >> __u16 DeviceRemovable;
> >> } __attribute__ ((packed)) ss;
> >> } u;
> >>} __attribute__ ((packed));
> >>
> >>The struct has been defined with __attribute__ ((packed)). So there is
> >>no alignment problem. Or we can
> >> hub->descriptor->u.ss.DeviceRemovable = (__force __u16)
> >> cpu_to_le16(port_removable);
> >>I think we also should define wHubDelay and DeviceRemovable as __le16
> >>for ss since they are little-endian order, right?
> >
> >Yes. Ask Sarah about changing it.
> hi Sarah:
> Do you have some comments about this?
Go ahead and change the xhci-hub.c code to remove the __force once you
change the usb_hub_descriptor's wHubDelay and DeviceRemovable fields to
__le16. They should have been marked as little endian from the
beginning.
Sarah Sharp
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