i915: Fix opregion notifications

opregion-based platforms will send ACPI video event 0x80 for a range of
notification types for legacy compatibility. This is interpreted as a
display switch event, which may not be appropriate in the circumstances.
When we receive such an event we should make sure that the platform is
genuinely requesting a display switch before passing that event through
to userspace.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Tested-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index db39e9e..ada4b4d 100644 (file)
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -46,7 +46,6 @@
 
 #define PREFIX "ACPI: "
 
-#define ACPI_VIDEO_CLASS               "video"
 #define ACPI_VIDEO_BUS_NAME            "Video Bus"
 #define ACPI_VIDEO_DEVICE_NAME         "Video Device"
 #define ACPI_VIDEO_NOTIFY_SWITCH       0x80
@@ -1445,7 +1444,8 @@ static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
        case ACPI_VIDEO_NOTIFY_SWITCH:  /* User requested a switch,
                                         * most likely via hotkey. */
                acpi_bus_generate_proc_event(device, event, 0);
-               keycode = KEY_SWITCHVIDEOMODE;
+               if (!acpi_notifier_call_chain(device, event, 0))
+                       keycode = KEY_SWITCHVIDEOMODE;
                break;
 
        case ACPI_VIDEO_NOTIFY_PROBE:   /* User plugged in or removed a video
@@ -1475,7 +1475,8 @@ static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
                break;
        }
 
-       acpi_notifier_call_chain(device, event, 0);
+       if (event != ACPI_VIDEO_NOTIFY_SWITCH)
+               acpi_notifier_call_chain(device, event, 0);
 
        if (keycode) {
                input_report_key(input, keycode, 1);

diff --git a/drivers/gpu/drm/i915/intel_opregion.c b/drivers/gpu/drm/i915/intel_opregion.c
index d2c7104..b7c5ddb 100644 (file)
--- a/drivers/gpu/drm/i915/intel_opregion.c
+++ b/drivers/gpu/drm/i915/intel_opregion.c
@@ -297,19 +297,26 @@ static int intel_opregion_video_event(struct notifier_block *nb,
        /* The only video events relevant to opregion are 0x80. These indicate
           either a docking event, lid switch or display switch request. In
           Linux, these are handled by the dock, button and video drivers.
-          We might want to fix the video driver to be opregion-aware in
-          future, but right now we just indicate to the firmware that the
-          request has been handled */
+       */
 
        struct opregion_acpi *acpi;
+       struct acpi_bus_event *event = data;
+       int ret = NOTIFY_OK;
+
+       if (strcmp(event->device_class, ACPI_VIDEO_CLASS) != 0)
+               return NOTIFY_DONE;
 
        if (!system_opregion)
                return NOTIFY_DONE;
 
        acpi = system_opregion->acpi;
+
+       if (event->type == 0x80 && !(acpi->cevt & 0x1))
+               ret = NOTIFY_BAD;
+
        acpi->csts = 0;
 
-       return NOTIFY_OK;
+       return ret;
 }
 
 static struct notifier_block intel_opregion_notifier = {

diff --git a/include/acpi/video.h b/include/acpi/video.h
index 0e98e67..61109f2 100644 (file)
--- a/include/acpi/video.h
+++ b/include/acpi/video.h
@@ -5,6 +5,8 @@
 
 struct acpi_device;
 
+#define ACPI_VIDEO_CLASS       "video"
+
 #define ACPI_VIDEO_DISPLAY_CRT  1
 #define ACPI_VIDEO_DISPLAY_TV   2
 #define ACPI_VIDEO_DISPLAY_DVI  3