Re: [xHCI bug report]: some USB3.0 devices will be re-enumerated immediately after we safely remove it(but not plug out the cable)

[Lu, Baolu]

Hi,

Have you tried the latest kernel?
Can below commit change anything?

commit bb86cf569bbd7ad4dce581a37c7fbd748057e9dc
Author: Gavin Guo <gavin....@canonical.com>
Date:   Fri Jul 18 01:12:13 2014 +0800

    usb: Check if port status is equal to RxDetect
    
    When using USB 3.0 pen drive with the [AMD] FCH USB XHCI Controller
    [1022:7814], the second hotplugging will experience the USB 3.0 pen
    drive is recognized as high-speed device. After bisecting the kernel,
    I found the commit number 41e7e056cdc662f704fa9262e5c6e213b4ab45dd
    (USB: Allow USB 3.0 ports to be disabled.) causes the bug. After doing
    some experiments, the bug can be fixed by avoiding executing the function
    hub_usb3_port_disable(). Because the port status with [AMD] FCH USB
    XHCI Controlleris [1022:7814] is already in RxDetect
    (I tried printing out the port status before setting to Disabled state),
    it's reasonable to check the port status before really executing
    hub_usb3_port_disable().
    
    Fixes: 41e7e056cdc6 (USB: Allow USB 3.0 ports to be disabled.)
    Signed-off-by: Gavin Guo <gavin....@canonical.com>
    Acked-by: Alan Stern <st...@rowland.harvard.edu>
    Cc: <sta...@vger.kernel.org>
    Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

Thanks,
-baolu


On 2014年11月24日 16:22, cobec...@via-alliance.com wrote:
Hi All,

On Intel Z77(Fresco xHCI host controller integrated) platform and VIA
VT3456 platform, indeed with almost all the vendor's xHCI host
controller, some USB3.0 storage devices, such as WD/HGST TURBO mobile
MX3, will be re-enumerated immediately after we safely remove it in
Ubuntu distributors and but don't plug out the cable. For safely
removing, the sys file "remove" will be write and the
usb_remove_device() routine will be called.
In this case, xHCI driver places the port into disable state firstly and
then set it to RxDetect state. After these settings with the issued
devices, the link state will be U0, rather than Rxdetect/Polling, and
then the device will be re-enumerated.

Thanks a lot

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