From 456244aeecd54249096362a173dfe06b82a5cafa Mon Sep 17 00:00:00 2001
From: Macpaul Lin <macpaul.lin@mediatek.com>
Date: Tue, 19 Apr 2022 16:12:45 +0800
Subject: [PATCH] usb: mtu3: fix USB 3.0 dual-role-switch from device to host
Git-commit: 456244aeecd54249096362a173dfe06b82a5cafa
References: git-fixes
Patch-mainline: v5.18-rc5

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@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>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/usb/mtu3/mtu3_dr.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/mtu3/mtu3_dr.c b/drivers/usb/mtu3/mtu3_dr.c
index a6b04831b20b..9b8aded3d95e 100644
--- a/drivers/usb/mtu3/mtu3_dr.c
+++ b/drivers/usb/mtu3/mtu3_dr.c
@@ -21,10 +21,8 @@ static inline struct ssusb_mtk *otg_sx_to_ssusb(struct otg_switch_mtk *otg_sx)
 
 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 */
-- 
2.35.3