Re: [PATCH 0/2] i2c: i801: Detect SPD Write Disable and expose as adapter quirk

[Delaida Muminović]

Tested the series on a machine that hits this bug:

  Lenovo ThinkPad T14 Gen 6 (21QCS1NV00)
  Fedora 44, kernel 7.0.13-200.fc44.x86_64
  BIOS N4JET27W 1.17

This controller has SPD Write Disable set:

  i801_smbus 0000:00:1f.4: SPD Write Disable is set

Without the series, spd5118 binds at 15-0050 and resume fails with:

  spd5118 15-0050: Failed to write b = 0: -6
  spd5118 15-0050: PM: dpm_run_callback(): spd5118_resume [spd5118] returns -6
  spd5118 15-0050: PM: failed to resume async: error -6

I rebuilt i2c-i801 and spd5118 with this series on the above kernel. i801 now
marks the adapter with I2C_AQ_SPD_WRITE_DISABLED, and spd5118 declines to bind:

  spd5118 15-0050: SPD Write Disable is set on adapter; refusing probe

spd5118 is loaded but not bound to the SPD device, so spd5118_resume() is never
registered and the -6 failure can no longer occur. The approach works on this
hardware and is cleaner than blacklisting the module.

Tested-by: Delaida Muminovic <delaidamuminovic2@xxxxxxxxx>