Comment 0 for bug 1996198

[Impact]
Need this patch in so a BIOS upgrade won't cause issues on HP laptops.

 platform/x86: hp_wmi: Fix rfkill causing soft blocked wifi

After upgrading BIOS to U82 01.02.01 Rev.A, the console is flooded
strange char "^@" which printed out every second and makes login
nearly impossible. Also the below messages were shown both in console
and journal/dmesg every second:

usb 1-3: Device not responding to setup address.
usb 1-3: device not accepting address 4, error -71
usb 1-3: device descriptor read/all, error -71
usb usb1-port3: unable to enumerate USB device

Wifi is soft blocked by checking rfkill. When unblocked manually,
after few seconds it would be soft blocked again. So I was suspecting
something triggered rfkill to soft block wifi. At the end it was
fixed by removing hp_wmi module.

The root cause is the way hp-wmi driver handles command 1B on
post-2009 BIOS. In pre-2009 BIOS, command 1Bh return 0x4 to indicate
that BIOS no longer controls the power for the wireless devices.

Signed-off-by: Jorge Lopez <email address hidden>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216468
Reviewed-by: Mario Limonciello <email address hidden>
Link: https://<email address hidden>
Cc: <email address hidden>
Reviewed-by: Hans de Goede <email address hidden>
Signed-off-by: Hans de Goede <email address hidden>

[Test case]

test on a HP laptop with the new BIOS

[Where problems could occur]

from the commit:
  * In pre-2009 BIOS, command 1Bh return 0x4 to indicate that
  * BIOS no longer controls the power for the wireless
  * devices. All features supported by this command will no
  * longer be supported.

anyone running a laptop with obsolete pre-2009 BIOS probably won't notice the missing feature at this point.