This is a note to let you know that I've just added the patch titled
usb: mtu3: fix USB 3.0 dual-role-switch from device to host
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
usb-mtu3-fix-usb-3.0-dual-role-switch-from-device-to-host.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 456244aeecd54249096362a173dfe06b82a5cafa Mon Sep 17 00:00:00 2001
From: Macpaul Lin <macpaul.lin@xxxxxxxxxxxx>
Date: Tue, 19 Apr 2022 16:12:45 +0800
Subject: usb: mtu3: fix USB 3.0 dual-role-switch from device to host
From: Macpaul Lin <macpaul.lin@xxxxxxxxxxxx>
commit 456244aeecd54249096362a173dfe06b82a5cafa 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: d0ed062a8b75 ("usb: mtu3: dual-role mode support")
Cc: stable@xxxxxxxxxxxxxxx
Tested-by: Fabien Parent <fparent@xxxxxxxxxxxx>
Reviewed-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
Signed-off-by: Macpaul Lin <macpaul.lin@xxxxxxxxxxxx>
Signed-off-by: Tainping Fang <tianping.fang@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220419081245.21015-1-macpaul.lin@xxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/mtu3/mtu3_dr.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
--- a/drivers/usb/mtu3/mtu3_dr.c
+++ b/drivers/usb/mtu3/mtu3_dr.c
@@ -39,10 +39,8 @@ enum mtu3_vbus_id_state {
static void toggle_opstate(struct ssusb_mtk *ssusb)
{
- if (!ssusb->otg_switch.is_u3_drd) {
- mtu3_setbits(ssusb->mac_base, U3D_DEVICE_CONTROL, DC_SESSION);
- mtu3_setbits(ssusb->mac_base, U3D_POWER_MANAGEMENT, SOFT_CONN);
- }
+ mtu3_setbits(ssusb->mac_base, U3D_DEVICE_CONTROL, DC_SESSION);
+ mtu3_setbits(ssusb->mac_base, U3D_POWER_MANAGEMENT, SOFT_CONN);
}
/* only port0 supports dual-role mode */
Patches currently in stable-queue which might be from macpaul.lin@xxxxxxxxxxxx are
queue-4.14/usb-mtu3-fix-usb-3.0-dual-role-switch-from-device-to-host.patch
