[PATCH v1] hp_wmi causing rfkill soft blocked wifi

[Jorge Lopez <jorgealtxwork@gmail.com>]

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 <jorge.lopez2@hp.com>

---
Based on the latest platform-drivers-x86.git/for-next
---
 drivers/platform/x86/hp-wmi.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/x86/hp-wmi.c b/drivers/platform/x86/hp-wmi.c
index 627a6d0eaf83..29cd4e437d97 100644
--- a/drivers/platform/x86/hp-wmi.c
+++ b/drivers/platform/x86/hp-wmi.c
@@ -1300,8 +1300,15 @@ static int __init hp_wmi_bios_setup(struct platform_device *device)
 	wwan_rfkill = NULL;
 	rfkill2_count = 0;
 
-	if (hp_wmi_rfkill_setup(device))
-		hp_wmi_rfkill2_setup(device);
+	/*
+	 * 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.
+	 */
+	if (!hp_wmi_bios_2009_later())
+		if (hp_wmi_rfkill_setup(device))
+			hp_wmi_rfkill2_setup(device);
 
 	err = hp_wmi_hwmon_init();
 
-- 
2.34.1