Re: [REGRESSION] NFC broken on Thinkpad T14 Gen since 9c328f5

On Sat, Feb 07, 2026 at 01:25:29AM +0100, Lukas K. wrote:

On 06.02.26 17:24, Thorsten Leemhuis wrote:

quoted

On 2/6/26 16:15, Lukas K. wrote:

quoted

from 6.17.2 to 6.17.3, the integrated NFC reader (driver: nxp-nci_i2c)
in the Thinkpad T14 Gen 4 (AMD) stopped detecting tags. This can be
tested by running

sudo nfctool -1 -p -d nfc0

Looking at the commits between 6.17.2 and 6.17.3, 9c328f5 (net: nfc:
nci: Add parameter validation for packet data) was the only one related
to NFC.

To see if that commit indeed was the culprit, I reverted it on 6.18.7
and nfctool is detecting tags again.

Since the offending commit merely adds some bounds checks, the root
cause may very well be in another driver in the NFC stack.

Thx for the report. Seems Michael (now CCed) also ran into problems and
tried to fix them, but looks like that effort stalled; but might be good
to know if this fixes your problem, too:

https://lore.kernel.org/all/20260112124819.171028-1-michael.thalmeier@hale.at/ (local)

Hi Thorsten,

thanks for the pointer. Tried the patch you linked to and it works for me.

Don't know how to reply to the linked mail as I'm new to LKML, but one thing
caught my eye:

If you look at the page you will see:

Message-ID: [ref]

You can take the message ID and give it to b4:

$ b4 mbox 20260112124819.171028-1-michael.thalmeier@hale.at
Looking up https://lore.kernel.org/r/20260112124819.171028-1-michael.thalmeier%40hale.at
Grabbing thread from lore.kernel.org/all
2 messages in the thread
Saved ./20260112124819.171028-1-michael.thalmeier@hale.at.mbx

You can then open
20260112124819.171028-1-michael.thalmeier@hale.at.mbx in a mail client
as a mailbox and hit group reply to one of the messages.

    Andrew