[REGRESSION] iwlwifi IO_PAGE_FAULT and Master Disable Timed Out

[REGRESSION] iwlwifi IO_PAGE_FAULT and Master Disable Timed Out

[Chris Bainbridge]

Hi,

0eaa1f245ac0 ("wifi: iwlwifi: mvm: don't support the reset handshake for
old firmwares") introduced an intermittent boot regression on my laptop:

[   15.974991] iwlwifi 0000:01:00.0: AMD-Vi: Event logged [IO_PAGE_FAULT domain=0x000a address=0xbe9f5000 flags=0x0000]
[   15.976184] iwlwifi 0000:01:00.0: AMD-Vi: Event logged [IO_PAGE_FAULT domain=0x000a address=0xbe9f5400 flags=0x0000]
[   15.978501] iwlwifi 0000:01:00.0: Master Disable Timed Out, 100 usec

The commit only contains:

+       /* Those firmware versions claim to support the fw_reset_handshake
+        * but they are buggy.
+        */
+       if (IWL_UCODE_MAJOR(mvm->fw->ucode_ver) <= 77)
+               trans->conf.fw_reset_handshake = false;

The if condition is evaluating true on my laptop despite using firmware
ty-a0-gf-a0-89.ucode. So I suspect this is not the correct way to check
the firmware version?

Also comment #21 on bugzilla.kernel.org bug #220600 (which this commit
was supposed to fix) reports the same "Master Disable Timed Out" error
(although no IO_PAGE_FAULTS, probably the bad memory access is not
caught without iommu=strict).

#regzbot introduced: 0eaa1f245ac03ed0c6394159360532726f666811