sony-laptop: check for rfkill hard block at load time

"I recently (on a flight) I found out that when I boot with the hard-switch
activated, so turning off all wireless activity on my laptop, the state
is not correctly announced in /dev/rfkill (reading it with rfkill command,
or my own gnome applet)...

After turning off and on again the hard-switch the events were right."

We can fix this by querying the firmware at load time and calling
rfkill_set_hw_state().

Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Tested-by: Norbert Preining <preining@logic.at>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Mattia Dongili <malattia@linux.it>
CC: stable@kernel.org
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/platform/x86/sony-laptop.c

@@ -1078,6 +1078,8 @@ static int sony_nc_setup_rfkill(struct acpi_device *device,
 	struct rfkill *rfk;
 	enum rfkill_type type;
 	const char *name;
+	int result;
+	bool hwblock;
 
 	switch (nc_type) {
 	case SONY_WIFI:
@@ -1105,6 +1107,10 @@ static int sony_nc_setup_rfkill(struct acpi_device *device,
 	if (!rfk)
 		return -ENOMEM;
 
+	sony_call_snc_handle(0x124, 0x200, &result);
+	hwblock = !(result & 0x1);
+	rfkill_set_hw_state(rfk, hwblock);
+
 	err = rfkill_register(rfk);
 	if (err) {
 		rfkill_destroy(rfk);