This is a note to let you know that I've just added the patch titled
USB: fix bug of device descriptor got from superspeed device
to the 3.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
usb-fix-bug-of-device-descriptor-got-from-superspeed-device.patch
and it can be found in the queue-3.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From d8aec3dbdfd02627e198e7956ab4aaeba2a349fa Mon Sep 17 00:00:00 2001
From: Elric Fu <[email protected]>
Date: Mon, 26 Mar 2012 21:16:02 +0800
Subject: USB: fix bug of device descriptor got from superspeed device
From: Elric Fu <[email protected]>
commit d8aec3dbdfd02627e198e7956ab4aaeba2a349fa upstream.
When the Seagate Goflex USB3.0 device is attached to VIA xHCI
host, sometimes the device will downgrade 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.
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.
This patch should be backported to kernels as old as 3.2, or ones that
contain the commit 75d7cf72ab9fa01dc70877aa5c68e8ef477229dc "usbcore:
refine warm reset logic".
Signed-off-by: Elric Fu <[email protected]>
Acked-by: Andiry Xu <[email protected]>
Acked-by: Sergei Shtylyov <[email protected]>
Signed-off-by: Sarah Sharp <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/usb/core/hub.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -3072,6 +3072,22 @@ hub_port_init (struct usb_hub *hub, stru
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) &&
+ (le16_to_cpu(udev->descriptor.bcdUSB) < 0x0300)) {
+ dev_err(&udev->dev, "got 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;
Patches currently in stable-queue which might be from [email protected] are
queue-3.2/usb-fix-bug-of-device-descriptor-got-from-superspeed-device.patch
queue-3.2/xhci-don-t-write-zeroed-pointers-to-xhc-registers.patch
queue-3.2/xhci-add-xhci_reset_on_resume-quirk-for-via-xhci-host.patch
queue-3.2/xhci-restore-event-ring-dequeue-pointer-on-resume.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
