Re: [PATCH net-next] net: wwan: mhi_wwan_mbim: Silence sequence number glitch errors

[Loic Poulain]

On Wed, 12 Feb 2025 at 12:15, Stephan Gerhold
<stephan.gerhold@xxxxxxxxxx> wrote:
>
> 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@xxxxxxxxxx>

Reviewed-by: Loic Poulain <loic.poulain@xxxxxxxxxx>