tree de495a5bbd9f0399f3673ee9b00d69543a72630c
parent c7713e736526d8c9f6f87716fb90562a8ffaff2c
author Elric Fu <elricfu1@gmail.com> 1332767762 +0800
committer Sarah Sharp <sarah.a.sharp@linux.intel.com> 1334158138 -0700

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 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 <elricfu1@gmail.com>
Acked-by: Andiry Xu <Andiry.Xu@amd.com>
Acked-by: Sergei Shtylyov <sshtylyov@mvista.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org