dell-laptop: Do not cache hwswitch state

The hwswitch state can be changed at runtime, so make sure dell-laptop
always knows the current state. It can be modified by the userspace
utility smbios-wireless-ctl.
Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>

drivers/platform/x86/dell-laptop.c

@@ -309,8 +309,6 @@ static const struct dmi_system_id dell_quirks[] __initconst = {
 static struct calling_interface_buffer *buffer;
 static DEFINE_MUTEX(buffer_mutex);
 
-static int hwswitch_state;
-
 static void clear_buffer(void)
 {
 	memset(buffer, 0, sizeof(struct calling_interface_buffer));
@@ -553,20 +551,30 @@ static int dell_rfkill_set(void *data, bool blocked)
 	int disable = blocked ? 1 : 0;
 	unsigned long radio = (unsigned long)data;
 	int hwswitch_bit = (unsigned long)data - 1;
+	int hwswitch;
+	int status;
 	int ret;
 
 	get_buffer();
 
 	dell_send_request(buffer, 17, 11);
 	ret = buffer->output[0];
+	status = buffer->output[1];
 
 	if (ret != 0)
 		goto out;
 
+	clear_buffer();
+
+	buffer->input[0] = 0x2;
+	dell_send_request(buffer, 17, 11);
+	ret = buffer->output[0];
+	hwswitch = buffer->output[1];
+
 	/* If the hardware switch controls this radio, and the hardware
 	   switch is disabled, always disable the radio */
-	if ((hwswitch_state & BIT(hwswitch_bit)) &&
-	    !(buffer->output[1] & BIT(16)))
+	if (ret == 0 && (hwswitch & BIT(hwswitch_bit)) &&
+	    (status & BIT(0)) && !(status & BIT(16)))
 		disable = 1;
 
 	clear_buffer();
@@ -597,27 +605,43 @@ static void dell_rfkill_update_sw_state(struct rfkill *rfkill, int radio,
 }
 
 static void dell_rfkill_update_hw_state(struct rfkill *rfkill, int radio,
-					int status)
+					int status, int hwswitch)
 {
-	if (hwswitch_state & (BIT(radio - 1)))
+	if (hwswitch & (BIT(radio - 1)))
 		rfkill_set_hw_state(rfkill, !(status & BIT(16)));
 }
 
 static void dell_rfkill_query(struct rfkill *rfkill, void *data)
 {
+	int radio = ((unsigned long)data & 0xF);
+	int hwswitch;
 	int status;
 	int ret;
 
 	get_buffer();
+
 	dell_send_request(buffer, 17, 11);
 	ret = buffer->output[0];
 	status = buffer->output[1];
+
+	if (ret != 0 || !(status & BIT(0))) {
+		release_buffer();
+		return;
+	}
+
+	clear_buffer();
+
+	buffer->input[0] = 0x2;
+	dell_send_request(buffer, 17, 11);
+	ret = buffer->output[0];
+	hwswitch = buffer->output[1];
+
 	release_buffer();
 
 	if (ret != 0)
 		return;
 
-	dell_rfkill_update_hw_state(rfkill, (unsigned long)data, status);
+	dell_rfkill_update_hw_state(rfkill, radio, status, hwswitch);
 }
 
 static const struct rfkill_ops dell_rfkill_ops = {
@@ -629,13 +653,24 @@ static struct dentry *dell_laptop_dir;
 
 static int dell_debugfs_show(struct seq_file *s, void *data)
 {
+	int hwswitch_state;
+	int hwswitch_ret;
 	int status;
 	int ret;
 
 	get_buffer();
+
 	dell_send_request(buffer, 17, 11);
 	ret = buffer->output[0];
 	status = buffer->output[1];
+
+	clear_buffer();
+
+	buffer->input[0] = 0x2;
+	dell_send_request(buffer, 17, 11);
+	hwswitch_ret = buffer->output[0];
+	hwswitch_state = buffer->output[1];
+
 	release_buffer();
 
 	seq_printf(s, "return:\t%d\n", ret);
@@ -680,7 +715,8 @@ static int dell_debugfs_show(struct seq_file *s, void *data)
 	seq_printf(s, "Bit 21: WiGig is blocked:            %lu\n",
 		  (status & BIT(21)) >> 21);
 
-	seq_printf(s, "\nhwswitch_state:\t0x%X\n", hwswitch_state);
+	seq_printf(s, "\nhwswitch_return:\t%d\n", hwswitch_ret);
+	seq_printf(s, "hwswitch_state:\t0x%X\n", hwswitch_state);
 	seq_printf(s, "Bit 0 : Wifi controlled by switch:      %lu\n",
 		   hwswitch_state & BIT(0));
 	seq_printf(s, "Bit 1 : Bluetooth controlled by switch: %lu\n",
@@ -716,6 +752,7 @@ static const struct file_operations dell_debugfs_fops = {
 
 static void dell_update_rfkill(struct work_struct *ignored)
 {
+	int hwswitch = 0;
 	int status;
 	int ret;
 
@@ -728,16 +765,26 @@ static void dell_update_rfkill(struct work_struct *ignored)
 	if (ret != 0)
 		goto out;
 
+	clear_buffer();
+
+	buffer->input[0] = 0x2;
+	dell_send_request(buffer, 17, 11);
+	ret = buffer->output[0];
+
+	if (ret == 0 && (status & BIT(0)))
+		hwswitch = buffer->output[1];
+
 	if (wifi_rfkill) {
-		dell_rfkill_update_hw_state(wifi_rfkill, 1, status);
+		dell_rfkill_update_hw_state(wifi_rfkill, 1, status, hwswitch);
 		dell_rfkill_update_sw_state(wifi_rfkill, 1, status);
 	}
 	if (bluetooth_rfkill) {
-		dell_rfkill_update_hw_state(bluetooth_rfkill, 2, status);
+		dell_rfkill_update_hw_state(bluetooth_rfkill, 2, status,
+					    hwswitch);
 		dell_rfkill_update_sw_state(bluetooth_rfkill, 2, status);
 	}
 	if (wwan_rfkill) {
-		dell_rfkill_update_hw_state(wwan_rfkill, 3, status);
+		dell_rfkill_update_hw_state(wwan_rfkill, 3, status, hwswitch);
 		dell_rfkill_update_sw_state(wwan_rfkill, 3, status);
 	}
 
@@ -805,25 +852,15 @@ static int __init dell_setup_rfkill(void)
 	dell_send_request(buffer, 17, 11);
 	ret = buffer->output[0];
 	status = buffer->output[1];
-	clear_buffer();
-	buffer->input[0] = 0x2;
-	dell_send_request(buffer, 17, 11);
-	hwswitch_state = buffer->output[1];
 	release_buffer();
 
 	/* dell wireless info smbios call is not supported */
 	if (ret != 0)
 		return 0;
 
-	if (!(status & BIT(0))) {
-		if (force_rfkill) {
-			/* No hwsitch, clear all hw-controlled bits */
-			hwswitch_state &= ~7;
-		} else {
-			/* rfkill is only tested on laptops with a hwswitch */
-			return 0;
-		}
-	}
+	/* rfkill is only tested on laptops with a hwswitch */
+	if (!(status & BIT(0)) && !force_rfkill)
+		return 0;
 
 	if ((status & (1<<2|1<<8)) == (1<<2|1<<8)) {
 		wifi_rfkill = rfkill_alloc("dell-wifi", &platform_device->dev,