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USB: workaround for specified USB3 PHY disconnection det issue

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Some special SoCs (e.g. rk322xh) USB3 PHY have problem to detect
disconnection, they lose the ability to detect an absence of Rx
termination specified in USB3 spec Table 6-21, fortunately, the
USB3 PHY can detect port link state change when USB3 device is
unplugged, so we can do soft disconnect according to the PLC.

Change-Id: I2cbd62fddc8a1f9c5a264d705db43fb0cf3e035c
Signed-off-by: William Wu <wulf@rock-chips.com>
Signed-off-by: Frank Wang <frank.wang@rock-chips.com>
This commit is contained in:
William Wu
2017-09-27 10:32:21 +08:00
committed by William Wu
parent 1b69499a30
commit 0d2d5bbbfb
1 changed files with 18 additions and 1 deletions
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19
drivers/usb/core/hub.c
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@@ -5269,7 +5269,24 @@ static void port_event(struct usb_hub *hub, int port1)
} else {
usb_unlock_port(port_dev);
usb_lock_device(udev);
usb_reset_device(udev);
/**
* Some special SoCs (e.g. rk322xh) USB3 PHY lose the
* ability to detect a disconnection when USB3 device
* plug out, fortunately, it can detect port link state
* change here, so we can do soft disconnect according
* to the PLC here.
*
* And we only need to do the soft disconnect for root
* hub. In addition, we just reuse the autosuspend quirk
* but not add a new quirk for this issue. Because this
* issue always occurs with autosuspend problem.
*/
if (!hub->hdev->parent && (hdev->quirks &
USB_QUIRK_AUTO_SUSPEND))
usb_remove_device(udev);
else
usb_reset_device(udev);
usb_unlock_device(udev);
usb_lock_port(port_dev);
connect_change = 0;