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| author | Gavin Guo <gavin.guo@canonical.com> | 2014-07-17 21:12:13 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-07-28 19:00:02 +0400 |
| commit | 42cfa82f8201f91cdb7539a6e15c6ee15eee7f73 (patch) | |
| tree | b509be2b94d3461934ed4b1d1ddf902d0936b3fc /drivers | |
| parent | d02dae430d1f41f2c1dc8592f68569f90b86f6d9 (diff) | |
| download | linux-42cfa82f8201f91cdb7539a6e15c6ee15eee7f73.tar.xz | |
usb: Check if port status is equal to RxDetect
commit bb86cf569bbd7ad4dce581a37c7fbd748057e9dc upstream.
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.guo@canonical.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/core/hub.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 46efdca96952..63c217053668 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -887,6 +887,25 @@ static int hub_usb3_port_disable(struct usb_hub *hub, int port1) if (!hub_is_superspeed(hub->hdev)) return -EINVAL; + ret = hub_port_status(hub, port1, &portstatus, &portchange); + if (ret < 0) + return ret; + + /* + * USB controller Advanced Micro Devices, Inc. [AMD] FCH USB XHCI + * Controller [1022:7814] will have spurious result making the following + * usb 3.0 device hotplugging route to the 2.0 root hub and recognized + * as high-speed device if we set the usb 3.0 port link state to + * Disabled. Since it's already in USB_SS_PORT_LS_RX_DETECT state, we + * check the state here to avoid the bug. + */ + if ((portstatus & USB_PORT_STAT_LINK_STATE) == + USB_SS_PORT_LS_RX_DETECT) { + dev_dbg(&hub->ports[port1 - 1]->dev, + "Not disabling port; link state is RxDetect\n"); + return ret; + } + ret = hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_SS_DISABLED); if (ret) return ret; |