2012/3/19 Xu, Andiry <Andiry.Xu@xxxxxxx>: >> -----Original Message----- >> From: linux-usb-owner@xxxxxxxxxxxxxxx [mailto:linux-usb- >> owner@xxxxxxxxxxxxxxx] On Behalf Of Elric Fu >> Sent: Monday, March 19, 2012 2:56 PM >> To: Sarah Sharp >> Cc: Elric Fu; linux-usb@xxxxxxxxxxxxxxx >> Subject: [PATCH] USB: fix bug of device descriptor got from superspeed >> device >> >> When the Seagate Goflex USB3.0 device is attached to VIA xHCI >> host, sometimes the device will down mode to high speed. By >> the USB analyzer, I found the device finished the link training >> process and worked at superspeed mode. But the device descriptor >> got from the device shows the device works at 2.1. It is very >> strange and seems like the device controller of Seagate Goflex >> has a little confusion. >> > > What's the port link state when this occurs? Is it in U0 state? Yes, The port link state is U0. And the link training is successful. > >> The first 8 bytes of device descriptor should be: >> 12 01 00 03 00 00 00 09 >> >> But the first 8 bytes of wrong device descriptor are: >> 12 01 10 02 00 00 00 40 >> >> The wrong device descriptor caused the initialization of mass >> storage failed. After a while, the device would be recognized >> as a high speed device and works fine. >> >> This patch will warm reset the device to fix the issue after >> finding the bcdUSB field of device descriptor isn't 0x0300 >> but the speed mode of device is superspeed. >> >> Signed-off-by: Elric Fu <elricfu1@xxxxxxxxx> >> --- >> drivers/usb/core/hub.c | 16 ++++++++++++++++ >> 1 files changed, 16 insertions(+), 0 deletions(-) >> >> diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c >> index 265c2f6..5e4f3e0 100644 >> --- a/drivers/usb/core/hub.c >> +++ b/drivers/usb/core/hub.c >> @@ -3071,6 +3071,22 @@ hub_port_init (struct usb_hub *hub, struct >> usb_device *udev, int port1, >> if (retval) >> goto fail; >> >> + /* >> + * Some superspeed devices have finished the link training process >> + * and attached to a superspeed hub port, but the device descriptor >> + * got from those devices show they aren't superspeed devices. Warm >> + * reset the port attached by the devices can fix them. >> + */ >> + if ((udev->speed == USB_SPEED_SUPER) && >> + (udev->descriptor.bcdUSB != 0x0300)) { > > Perhaps using "< 0x0300" is better. > Maybe there will be 3.01, 3.10 devices in the future. You're right. I will modify it.Thanks. Best Regards, Elric > > Thanks, > Andiry > >> + dev_err(&udev->dev, "get a wrong device descriptor, " >> + "warm reset device\n"); >> + hub_port_reset(hub, port1, udev, >> + HUB_BH_RESET_TIME, true); >> + retval = -EINVAL; >> + goto fail; >> + } >> + >> if (udev->descriptor.bMaxPacketSize0 == 0xff || >> udev->speed == USB_SPEED_SUPER) >> i = 512; >> -- >> 1.7.9.1 >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-usb" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
