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usb: mtu3: fix random remote wakeup

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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: b1a344589e ("usb: mtu3: support ip-sleep wakeup for MT8183")
Cc: stable@vger.kernel.org
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/20210826083637.33237-2-chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Chunfeng Yun 2021-08-26 16:36:37 +08:00 committed by Greg Kroah-Hartman
parent 50fdcb56c4
commit d98a30ccdc
2 changed files with 4 additions and 1 deletions
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2
drivers/usb/mtu3/mtu3_host.c
View File

@ -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;

3
drivers/usb/mtu3/mtu3_plat.c
View File

@ -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;