net: wwan: mhi_wwan_mbim: Silence sequence number glitch errors
authorStephan Gerhold <stephan.gerhold@linaro.org>
Wed, 12 Feb 2025 11:15:35 +0000 (12:15 +0100)
committerJakub Kicinski <kuba@kernel.org>
Fri, 14 Feb 2025 21:39:55 +0000 (13:39 -0800)
commit0d1fac6d26aff5df21bb4ec980d9b7a11c410b96
tree92592a5c74b7d292e7936f3ce7a121bf5209bb6f
parent054e61bb1de4fa02d148344152007facbcb28583
net: wwan: mhi_wwan_mbim: Silence sequence number glitch errors

When using the Qualcomm X55 modem on the ThinkPad X13s, the kernel log is
constantly being filled with errors related to a "sequence number glitch",
e.g.:

[ 1903.284538] sequence number glitch prev=16 curr=0
[ 1913.812205] sequence number glitch prev=50 curr=0
[ 1923.698219] sequence number glitch prev=142 curr=0
[ 2029.248276] sequence number glitch prev=1555 curr=0
[ 2046.333059] sequence number glitch prev=70 curr=0
[ 2076.520067] sequence number glitch prev=272 curr=0
[ 2158.704202] sequence number glitch prev=2655 curr=0
[ 2218.530776] sequence number glitch prev=2349 curr=0
[ 2225.579092] sequence number glitch prev=6 curr=0

Internet connectivity is working fine, so this error seems harmless. It
looks like modem does not preserve the sequence number when entering low
power state; the amount of errors depends on how actively the modem is
being used.

A similar issue has also been seen on USB-based MBIM modems [1]. However,
in cdc_ncm.c the "sequence number glitch" message is a debug message
instead of an error. Apply the same to the mhi_wwan_mbim.c driver to
silence these errors when using the modem.

[1]: https://lists.freedesktop.org/archives/libmbim-devel/2016-November/000781.html

Signed-off-by: Stephan Gerhold <stephan.gerhold@linaro.org>
Reviewed-by: Loic Poulain <loic.poulain@linaro.org>
Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://patch.msgid.link/20250212-mhi-wwan-mbim-sequence-glitch-v1-1-503735977cbd@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
drivers/net/wwan/mhi_wwan_mbim.c