Some platforms, e.g. 8183/8192, use low level latch way to keep
wakeup signal, it may latch a wrong signal if debounce more time,
and enable wakeup earlier.
____________________
ip_sleep ____/ \__________
___________________
wakeup_signal ____________/ \______
_______________________________
wakeup_en _______/
^ ^
|(1) |(2)
latch wakeup_signal mistakenly at (1), should latch it at (2);
Workaround: delay about 100us to enable wakeup, meanwhile decrease
debounce time.
Fixes: b1a344589eea ("usb: mtu3: support ip-sleep wakeup for MT8183")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
---
drivers/usb/mtu3/mtu3_host.c | 2 +-
drivers/usb/mtu3/mtu3_plat.c | 3 +++
2 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/mtu3/mtu3_host.c b/drivers/usb/mtu3/mtu3_host.c
index 7d528f3c2482..f3903367a6a0 100644
--- a/drivers/usb/mtu3/mtu3_host.c
+++ b/drivers/usb/mtu3/mtu3_host.c
@@ -62,7 +62,7 @@ static void ssusb_wakeup_ip_sleep_set(struct ssusb_mtk *ssusb, bool enable)
case SSUSB_UWK_V1_1:
reg = ssusb->uwk_reg_base + PERI_WK_CTRL0;
msk = WC0_IS_EN | WC0_IS_C(0xf) | WC0_IS_P;
- val = enable ? (WC0_IS_EN | WC0_IS_C(0x8)) : 0;
+ val = enable ? (WC0_IS_EN | WC0_IS_C(0x1)) : 0;
break;
case SSUSB_UWK_V1_2:
reg = ssusb->uwk_reg_base + PERI_WK_CTRL0;
diff --git a/drivers/usb/mtu3/mtu3_plat.c b/drivers/usb/mtu3/mtu3_plat.c
index 5b3f7f73cb40..f13531022f4a 100644
--- a/drivers/usb/mtu3/mtu3_plat.c
+++ b/drivers/usb/mtu3/mtu3_plat.c
@@ -63,6 +63,9 @@ static int wait_for_ip_sleep(struct ssusb_mtk *ssusb)
if (ret) {
dev_err(ssusb->dev, "ip sleep failed!!!\n");
ret = -EBUSY;
+ } else {
+ /* workaround: avoid wrong wakeup signal latch for some soc */
+ usleep_range(100, 200);
}
return ret;
--
2.18.0
