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 the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: usb-quirks-ignore-remote-wake-up-on-fibocom-l850-gl-lte-modem.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 0bd860493f81eb2a46173f6f5e44cc38331c8dbd Mon Sep 17 00:00:00 2001 From: Vincent Palatin <vpalatin@xxxxxxxxxxxx> Date: Fri, 19 Mar 2021 13:48:02 +0100 Subject: USB: quirks: ignore remote wake-up on Fibocom L850-GL LTE modem From: Vincent Palatin <vpalatin@xxxxxxxxxxxx> commit 0bd860493f81eb2a46173f6f5e44cc38331c8dbd upstream. 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@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/20210319124802.2315195-1-vpalatin@xxxxxxxxxxxx Cc: stable <stable@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/core/quirks.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/usb/core/quirks.c +++ b/drivers/usb/core/quirks.c @@ -498,6 +498,10 @@ static const struct usb_device_id usb_qu /* 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 }, Patches currently in stable-queue which might be from vpalatin@xxxxxxxxxxxx are queue-4.19/usb-quirks-ignore-remote-wake-up-on-fibocom-l850-gl-lte-modem.patch