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authorCorentin Chary <corentin.chary@gmail.com>2012-06-13 09:32:01 +0200
committerMatthew Garrett <mjg@redhat.com>2012-07-28 00:11:48 -0400
commitf838eb5bd257e8a666aa8c451058fa198df7e299 (patch)
tree4a0ce12abef63c20367256b24f1bdf183f284238 /drivers/acpi
parent1eb3fe1d3b6b9bf6045eb12f0c3ac12569169870 (diff)
downloadlinux-linaro-stable-f838eb5bd257e8a666aa8c451058fa198df7e299.tar.gz
acpi: add a way to promote/demote vendor backlight drivers
Instead of adding a big blacklist in video_detect.c to set ACPI_VIDEO_BACKLIGHT_DMI_VENDOR correctly, let external modules promote or demote themselves when they know the generic video module won't work. Currently drivers where using acpi_video_unregister() directly but: - That didn't respect any acpi_backlight=[video|vendor] parameter provided by the user. - Any later call to acpi_video_register() would still re-load the generic video module (and some gpu drivers are doing that). This patch fix those two issues. Signed-off-by: Corentin Chary <corentin.chary@gmail.com> Signed-off-by: Matthew Garrett <mjg@redhat.com>
Diffstat (limited to 'drivers/acpi')
-rw-r--r--drivers/acpi/video_detect.c31
1 files changed, 29 insertions, 2 deletions
diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c
index 45d8097ef4cf..942fa2a998f7 100644
--- a/drivers/acpi/video_detect.c
+++ b/drivers/acpi/video_detect.c
@@ -182,8 +182,7 @@ long acpi_video_get_capabilities(acpi_handle graphics_handle)
}
EXPORT_SYMBOL(acpi_video_get_capabilities);
-/* Returns true if video.ko can do backlight switching */
-int acpi_video_backlight_support(void)
+static void acpi_video_caps_check(void)
{
/*
* We must check whether the ACPI graphics device is physically plugged
@@ -191,6 +190,34 @@ int acpi_video_backlight_support(void)
*/
if (!acpi_video_caps_checked)
acpi_video_get_capabilities(NULL);
+}
+
+/* Promote the vendor interface instead of the generic video module.
+ * This function allow DMI blacklists to be implemented by externals
+ * platform drivers instead of putting a big blacklist in video_detect.c
+ * After calling this function you will probably want to call
+ * acpi_video_unregister() to make sure the video module is not loaded
+ */
+void acpi_video_dmi_promote_vendor(void)
+{
+ acpi_video_caps_check();
+ acpi_video_support |= ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
+}
+EXPORT_SYMBOL(acpi_video_dmi_promote_vendor);
+
+/* To be called when a driver who previously promoted the vendor
+ * interface */
+void acpi_video_dmi_demote_vendor(void)
+{
+ acpi_video_caps_check();
+ acpi_video_support &= ~ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
+}
+EXPORT_SYMBOL(acpi_video_dmi_demote_vendor);
+
+/* Returns true if video.ko can do backlight switching */
+int acpi_video_backlight_support(void)
+{
+ acpi_video_caps_check();
/* First check for boot param -> highest prio */
if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR)