Skip to content
Snippets Groups Projects
user avatar
Vincent Palatin authored
[ Upstream commit f3a1a937 ]

This reverts commit 0bd86049.

While the patch was working as stated,ie preventing the L850-GL LTE modem
from crashing on some U3 wake-ups due to a race condition between the
host wake-up and the modem-side wake-up, when using the MBIM interface,
this would force disabling the USB runtime PM on the device.

The increased power consumption is significant for LTE laptops,
and given that with decently recent modem firmwares, when the modem hits
the bug, it automatically recovers (ie it drops from the bus, but
automatically re-enumerates after less than half a second, rather than being
stuck until a power cycle as it was doing with ancient firmware), for
most people, the trade-off now seems in favor of re-enabling it by
default.

For people with access to the platform code, the bug can also be worked-around
successfully by changing the USB3 LFPM polling off-time for the XHCI
controller in the BIOS code.

Signed-off-by: default avatarVincent Palatin <vpalatin@chromium.org>
Link: https://lore.kernel.org/r/20210721092516.2775971-1-vpalatin@chromium.org


Fixes: 0bd86049 ("USB: quirks: ignore remote wake-up on Fibocom L850-GL LTE modem")
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
7a78b17f
Name Last commit Last update