dell-laptop: Only install the i8042 filter when rfkill is active

Installing the i8042 filter is not useful on machines where rfkill is not
whitelisted, so move the filter installation into dell_setup_rfkill,
after the whitelist check.

This avoids doing a needless and potentially troublesome rfkill query
(dell_send_request(buf, 17, 11)) when the wireless Fn key gets pressed on
non whitelisted laptops.

This patch was written as a result of:
https://bugzilla.redhat.com/show_bug.cgi?id=1045807
It is not yet clear if this is related, but it is a good idea to not register
the i8042 filter in general.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>

1 files changed, 32 insertions, 31 deletions

diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c
index d2ceb761a7a2..fed4111ac31a 100644
--- a/drivers/platform/x86/dell-laptop.c
+++ b/drivers/platform/x86/dell-laptop.c
@@ -559,6 +559,29 @@ static void dell_update_rfkill(struct work_struct *ignored)
 }
 static DECLARE_DELAYED_WORK(dell_rfkill_work, dell_update_rfkill);
 
+static bool dell_laptop_i8042_filter(unsigned char data, unsigned char str,
+                              struct serio *port)
+{
+        static bool extended;
+
+        if (str & 0x20)
+                return false;
+
+        if (unlikely(data == 0xe0)) {
+                extended = true;
+                return false;
+        } else if (unlikely(extended)) {
+                switch (data) {
+                case 0x8:
+                        schedule_delayed_work(&dell_rfkill_work,
+                                              round_jiffies_relative(HZ / 4));
+                        break;
+                }
+                extended = false;
+        }
+
+        return false;
+}
 
 static int __init dell_setup_rfkill(void)
 {
@@ -636,7 +659,16 @@ static int __init dell_setup_rfkill(void)
                         goto err_wwan;
         }
 
+        ret = i8042_install_filter(dell_laptop_i8042_filter);
+        if (ret) {
+                pr_warn("Unable to install key filter\n");
+                goto err_filter;
+        }
+
         return 0;
+err_filter:
+        if (wwan_rfkill)
+                rfkill_unregister(wwan_rfkill);
 err_wwan:
         rfkill_destroy(wwan_rfkill);
         if (bluetooth_rfkill)
@@ -758,30 +790,6 @@ static void touchpad_led_exit(void)
         led_classdev_unregister(&touchpad_led);
 }
 
-static bool dell_laptop_i8042_filter(unsigned char data, unsigned char str,
-                              struct serio *port)
-{
-        static bool extended;
-
-        if (str & 0x20)
-                return false;
-
-        if (unlikely(data == 0xe0)) {
-                extended = true;
-                return false;
-        } else if (unlikely(extended)) {
-                switch (data) {
-                case 0x8:
-                        schedule_delayed_work(&dell_rfkill_work,
-                                              round_jiffies_relative(HZ / 4));
-                        break;
-                }
-                extended = false;
-        }
-
-        return false;
-}
-
 static int __init dell_init(void)
 {
         int max_intensity = 0;
@@ -831,12 +839,6 @@ static int __init dell_init(void)
                 goto fail_rfkill;
         }
 
-        ret = i8042_install_filter(dell_laptop_i8042_filter);
-        if (ret) {
-                pr_warn("Unable to install key filter\n");
-                goto fail_filter;
-        }
-
         if (quirks && quirks->touchpad_led)
                 touchpad_led_init(&platform_device->dev);
 
@@ -888,7 +890,6 @@ static int __init dell_init(void)
 fail_backlight:
         i8042_remove_filter(dell_laptop_i8042_filter);
         cancel_delayed_work_sync(&dell_rfkill_work);
-fail_filter:
         dell_cleanup_rfkill();
 fail_rfkill:
         free_page((unsigned long)bufferpage);