diff options
| author |   Chunfeng Yun <chunfeng.yun@mediatek.com> | 2021-08-26 16:36:37 +0800 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-08-26 13:41:52 +0200 |
| commit | d98a30ccdc839947c9233369744341d1fa54439c (patch) | |
| tree | b697f6f128ca3b9c667c70f37834713fe794f34c /drivers/usb/mtu3/mtu3_plat.c | |
| parent | usb: mtu3: return successful suspend status (diff) | |
| download | linux-rng-d98a30ccdc839947c9233369744341d1fa54439c.tar.xz linux-rng-d98a30ccdc839947c9233369744341d1fa54439c.zip | |
usb: mtu3: fix random remote wakeup
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@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>
Diffstat (limited to 'drivers/usb/mtu3/mtu3_plat.c')
| -rw-r--r-- | drivers/usb/mtu3/mtu3_plat.c | 3 |
1 files changed, 3 insertions, 0 deletions
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; |