[136/205] USB: Fix USB3.0 Port Speed Downgrade after port reset
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From: Greg KH on 30 Jul 2010 14:20 2.6.34-stable review patch. If anyone has any objections, please let us know. ------------------ From: Sarah Sharp <sarah.a.sharp(a)linux.intel.com> commit 809cd1cb80d7dffe75dc94bc94ef2aab3dadc86a upstream. Without this fix, a USB 3.0 port is downgraded to full speed after a port reset of a configured device. The USB 3.0 terminations will be disabled permanently, and USB 3.0 devices will always enumerate as full speed devices, until the host controller is unplugged (if it is an ExpressCard) or the computer is rebooted. Fajun Chen traced this traced the speed downgrade issue to the port reset and the interpretation of port status in USB hub driver code. The hub code was not testing for the port being a SuperSpeed port, and it fell through to the else case of Full Speed. The following patch adds SuperSpeed mapping from the port status, and fixes the speed downgrade issue. Reported-by: Fajun Chen <fajun.chen(a)seagate.com> Signed-off-by: Sarah Sharp <sarah.a.sharp(a)linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)suse.de> --- drivers/usb/core/hub.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -1971,6 +1971,8 @@ static int hub_port_wait_reset(struct us (portstatus & USB_PORT_STAT_ENABLE)) { if (hub_is_wusb(hub)) udev->speed = USB_SPEED_WIRELESS; + else if (portstatus & (1 << USB_PORT_FEAT_SUPERSPEED)) + udev->speed = USB_SPEED_SUPER; else if (portstatus & USB_PORT_STAT_HIGH_SPEED) udev->speed = USB_SPEED_HIGH; else if (portstatus & USB_PORT_STAT_LOW_SPEED) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |