This is a note to let you know that I've just added the patch titled

USB: quirks: ignore remote wake-up on Fibocom L850-GL LTE modem

to my usb git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git in the usb-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From 0bd860493f81eb2a46173f6f5e44cc38331c8dbd Mon Sep 17 00:00:00 2001

From: Vincent Palatin vpalatin@chromium.org Date: Fri, 19 Mar 2021 13:48:02 +0100 Subject: USB: quirks: ignore remote wake-up on Fibocom L850-GL LTE modem

This LTE modem (M.2 card) has a bug in its power management: there is some kind of race condition for U3 wake-up between the host and the device. The modem firmware sometimes crashes/locks when both events happen at the same time and the modem fully drops off the USB bus (and sometimes re-enumerates, sometimes just gets stuck until the next reboot).

Tested with the modem wired to the XHCI controller on an AMD 3015Ce platform. Without the patch, the modem dropped of the USB bus 5 times in 3 days. With the quirk, it stayed connected for a week while the 'runtime_suspended_time' counter incremented as excepted.

Signed-off-by: Vincent Palatin vpalatin@chromium.org Link: https://lore.kernel.org/r/20210319124802.2315195-1-vpalatin@chromium.org Cc: stable stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/core/quirks.c | 4 ++++ 1 file changed, 4 insertions(+)

diff --git a/drivers/usb/core/quirks.c b/drivers/usb/core/quirks.c index 6ade3daf7858..76ac5d6555ae 100644 --- a/drivers/usb/core/quirks.c +++ b/drivers/usb/core/quirks.c @@ -498,6 +498,10 @@ static const struct usb_device_id usb_quirk_list[] = { /* DJI CineSSD */ { USB_DEVICE(0x2ca3, 0x0031), .driver_info = USB_QUIRK_NO_LPM },

+ /* Fibocom L850-GL LTE Modem */ + { USB_DEVICE(0x2cb7, 0x0007), .driver_info = + USB_QUIRK_IGNORE_REMOTE_WAKEUP }, + /* INTEL VALUE SSD */ { USB_DEVICE(0x8086, 0xf1a5), .driver_info = USB_QUIRK_RESET_RESUME },