[stable request] mt7921e: backport two mt76 fixes to 6.12.y

[stable request] mt7921e: backport two mt76 fixes to 6.12.y

[Ajrat Makhmutov]

Hi,

Please consider backporting the following two upstream commits to the
6.12.y stable tree. Both are in Linus' tree and both cherry-pick cleanly
onto 6.12.y:

  2425dc7beaadc ("wifi: mt76: mt7921: avoid undesired changes of the preset regulatory domain")
  5ed54896b6bd4 ("wifi: mt76: mt7921: fix a potential scan no APs")

Together they fix a hard-to-reproduce MT7921e (MT7921 PCIe) lockup we have
been tracking on ALT Linux: after a disconnect (signal loss / AP deauth) or
repeated reconnects the chip ends up in a wrong firmware state and stops
scanning/associating to any network, recoverable only by a chip reset or a
module reload. The symptom is reproducible on 6.12.y and gone on 7.1. We
could not bisect the symptom to a single upstream commit, but these two are
the relevant fixes on the mt7921e path:

  - 5ed54896b6bd4 aborts the granted ROC channel before station removal, so
    the firmware is not left in a wrong state that makes subsequent scans
    return no APs.

  - 2425dc7beaadc stops a connected AP's country IE from re-triggering
    regulatory/CLC reprogramming once the user has already set a regdomain,
    which we observed leaving the firmware power/regulatory tables in a bad
    state.

Neither commit carries a Cc: stable tag, which is why they were not picked
up automatically.

Both have been tested on real MT7921e hardware (Acer Aspire 5 A517-52,
ASUS VivoBook S14, Lenovo IdeaPad Slim 5 14AHP9) running the 6.12 kernel.

BugLink: https://bugzilla.altlinux.org/54853

Thanks,
Ajrat Makhmutov

Re: [stable request] mt7921e: backport two mt76 fixes to 6.12.y

[Sasha Levin]

On Tue, Jun 10, 2026 at 11:09:43AM +0300, Ajrat Makhmutov wrote:
> Please backport to 6.12.y:
>   2425dc7beaad wifi: mt76: mt7921: avoid undesired changes of the preset regulatory domain
>   5ed54896b6bd wifi: mt76: mt7921: fix a potential scan no APs

I'm going to hold off on this one. The second commit, 5ed54896b6bd,
introduces a reachable dev->mutex self-deadlock on STA-remove-while-ROC;
the follow-up that cures it (d5059e52) isn't in any stable tree and was
never marked for stable (it's only in linux-next so far).

So taking these two alone would queue a deadlock. If d5059e52 lands
upstream (or you can confirm it's headed to stable), please resend the
request as all three together and I'll take them for 6.12.y.

--
Thanks,
Sasha

Re: [stable request] mt7921e: backport two mt76 fixes to 6.12.y

[Ajrat Makhmutov]

Hi Sasha,

> I'm going to hold off on this one. The second commit, 5ed54896b6bd,
> introduces a reachable dev->mutex self-deadlock on STA-remove-while-ROC;
> the follow-up that cures it (d5059e52) isn't in any stable tree and was
> never marked for stable (it's only in linux-next so far).

Thanks, and good catch.
I'll resend the request for all three together as soon as it lands in 
Linus' tree.

Note for whenever it does: when applied to 6.12.y, d5059e52 needs one 
trivial
change - keep del_timer_sync() instead of timer_delete_sync(), as the timer
API rename is not present in 6.12.y.

Thanks,
Ajrat

Re: [stable request] mt7921e: backport two mt76 fixes to 6.12.y

[Ajrat Makhmutov]

Hi Sasha,

> So taking these two alone would queue a deadlock. If d5059e52 lands
> upstream (or you can confirm it's headed to stable), please resend the
> request as all three together and I'll take them for 6.12.y.

d5059e52 is in mainline - it's already in v7.1-rc6, not just linux-next -
so here is the full set; please apply all three to 6.12.y together:

     2425dc7beaadc ("wifi: mt76: mt7921: avoid undesired changes of the 
preset regulatory domain")
     5ed54896b6bd4 ("wifi: mt76: mt7921: fix a potential scan no APs")
     d5059e52fd8bc ("wifi: mt76: mt7921: fix potential deadlock in 
mt7921_roc_abort_sync")

One note for the 6.12.y backport of d5059e52: keep del_timer_sync() instead
of timer_delete_sync() - the timer API rename is not present in 6.12.y. The
other two cherry-pick cleanly.

Tested together on real MT7921e hardware (Acer Aspire 5 A517-52, ASUS
VivoBook S14, Lenovo IdeaPad Slim 5 14AHP9) on 6.12.

Thanks,
Ajrat

Re: [stable request] mt7921e: backport two mt76 fixes to 6.12.y

[Sasha Levin]

> Please backport the following mt76/mt7921 fixes to 6.12.y:
>   - avoid undesired changes of the preset regulatory domain
>   - fix a potential scan no APs
>   - fix potential deadlock in mt7921_roc_abort_sync

All three are now queued for 6.12, thanks. The roc_abort_sync fix was
adapted to keep del_timer_sync(), since the timer rename is absent in
6.12.

--
Thanks,
Sasha