Re: [PATCH net] igc: Disable PCIe L1.2 substate on I225-LMvP and I226-LMvP devices

[sashiko-bot@kernel.org]

> Commit 0325143b59c6 ("igc: disable L1.2 PCI-E link substate to avoid
> performance issue") disabled the L1.2 substate on I226 controllers due
> to hardware exit latency limitations. However, IGC_DEV_ID_I226_LMVP
> (0x5503) was omitted from igc_is_device_id_i226(), and IGC_DEV_ID_I225_LMVP
> (0x5502) exhibits the same L1.2 exit latency constraints.
> 
> On systems where I225-LMvP is connected behind Thunderbolt/USB4 bridges
> (such as the HP Thunderbolt Dock G4), negotiating L1.2 triggers severe
> BadDLLP packet framing errors, link timeouts, and system hangs during
> shutdown. An earlier attempt ("igc: Mask replay rollover/timeout errors
> in I225_LMVP") proposed masking AER reporting. However, as Bjorn
> Helgaas noted in review of that patch, simply masking errors is
> undesirable and fixing the root cause is preferable; disabling L1.2
> prevents the link from entering the unstable substate entirely.
> 
> Include IGC_DEV_ID_I226_LMVP in igc_is_device_id_i226() and disable the
> L1.2 substate for I225-LMvP across probe, resume, and error recovery to
> ensure link stability without masking AER errors.
> 
> Fixes: 0325143b59c6 ("igc: disable L1.2 PCI-E link substate to avoid performance issue")
> Link: https://lore.kernel.org/lkml/eb5a9805-3e53-ec22-696e-21c6b8cf0bfc@molgen.mpg.de/T/
> Signed-off-by: Daniel Viaño <danividanivi@gmail.com>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20260925112850.189302-1-danividanivi@gmail.com?part=1