[PATCH 1/2] usb: mtu3: disable USB2 LPM

[Chunfeng Yun]

A SuperSpeed device shall include the USB 2.0 extension descriptor
and shall support LPM when operating in USB 2.0 HS mode(see usb3.2
spec9.6.2.1). But we always don't support it, so disable it by
default, otherwise device will enter LPM suspend mode when
connected to Win10 system.

Signed-off-by: Chunfeng Yun <chunfeng.yun at mediatek.com>
---
 drivers/usb/mtu3/mtu3_core.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/usb/mtu3/mtu3_core.c b/drivers/usb/mtu3/mtu3_core.c
index 9dd0216..50d6a40 100644
--- a/drivers/usb/mtu3/mtu3_core.c
+++ b/drivers/usb/mtu3/mtu3_core.c
@@ -604,6 +604,8 @@ static void mtu3_regs_init(struct mtu3 *mtu)
 	mtu3_clrbits(mbase, U3D_MISC_CTRL, VBUS_FRC_EN | VBUS_ON);
 	/* enable automatical HWRW from L1 */
 	mtu3_setbits(mbase, U3D_POWER_MANAGEMENT, LPM_HRWE);
+	/* always reject LPM request */
+	mtu3_setbits(mbase, U3D_POWER_MANAGEMENT, LPM_MODE(1));
 
 	/* use new QMU format when HW version >= 0x1003 */
 	if (mtu->gen2cp)
-- 
1.9.1