commit 456244aeec upstream.
Issue description:
When an OTG port has been switched to device role and then switch back
to host role again, the USB 3.0 Host (XHCI) will not be able to detect
"plug in event of a connected USB 2.0/1.0 ((Highspeed and Fullspeed)
devices until system reboot.
Root cause and Solution:
There is a condition checking flag "ssusb->otg_switch.is_u3_drd" in
toggle_opstate(). At the end of role switch procedure, toggle_opstate()
will be called to set DC_SESSION and SOFT_CONN bit. If "is_u3_drd" was
set and switched the role to USB host 3.0, bit DC_SESSION and SOFT_CONN
will be skipped hence caused the port cannot detect connected USB 2.0
(Highspeed and Fullspeed) devices. Simply remove the condition check to
solve this issue.
Fixes: d0ed062a8b ("usb: mtu3: dual-role mode support")
Cc: stable@vger.kernel.org
Tested-by: Fabien Parent <fparent@baylibre.com>
Reviewed-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Macpaul Lin <macpaul.lin@mediatek.com>
Signed-off-by: Tainping Fang <tianping.fang@mediatek.com>
Link: https://lore.kernel.org/r/20220419081245.21015-1-macpaul.lin@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
0da0ac8941