dell-laptop: Toggle the unsupported hardware killswitch

It is found on Dell Inspiron 1018 that the firmware reports that the hardware
killswitch is not supported. This makes the rfkill key not functional.

This patch forces the driver to toggle the firmware rfkill status in the case
that the hardware killswitch is indicated as unsupported by the firmware.
Signed-off-by: Keng-Yu Lin <keng-yu.lin@canonical.com>
Tested-by: Alessio Igor Bogani <abogani@texware.it>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

drivers/platform/x86/dell-laptop.c

@@ -290,9 +290,12 @@ static int dell_rfkill_set(void *data, bool blocked)
 	dell_send_request(buffer, 17, 11);
 
 	/* If the hardware switch controls this radio, and the hardware
-	   switch is disabled, don't allow changing the software state */
+	   switch is disabled, don't allow changing the software state.
+	   If the hardware switch is reported as not supported, always
+	   fire the SMI to toggle the killswitch. */
 	if ((hwswitch_state & BIT(hwswitch_bit)) &&
-	    !(buffer->output[1] & BIT(16))) {
+	    !(buffer->output[1] & BIT(16)) &&
+	    (buffer->output[1] & BIT(0))) {
 		ret = -EINVAL;
 		goto out;
 	}
@@ -398,6 +401,23 @@ static const struct file_operations dell_debugfs_fops = {
 
 static void dell_update_rfkill(struct work_struct *ignored)
 {
+	int status;
+
+	get_buffer();
+	dell_send_request(buffer, 17, 11);
+	status = buffer->output[1];
+	release_buffer();
+
+	/* if hardware rfkill is not supported, set it explicitly */
+	if (!(status & BIT(0))) {
+		if (wifi_rfkill)
+			dell_rfkill_set((void *)1, !((status & BIT(17)) >> 17));
+		if (bluetooth_rfkill)
+			dell_rfkill_set((void *)2, !((status & BIT(18)) >> 18));
+		if (wwan_rfkill)
+			dell_rfkill_set((void *)3, !((status & BIT(19)) >> 19));
+	}
+
 	if (wifi_rfkill)
 		dell_rfkill_query(wifi_rfkill, (void *)1);
 	if (bluetooth_rfkill)