drm/i915: Toshiba CB35 has a controllable backlight

commit d4967d8c6d4f52623f2be8eaff0b445dc5863c92 upstream.

The Toshiba CB35 Chromebook (with Celeron 2955U CPU) has a controllable
backlight although its VBT reports otherwise. Apply quirk to ignore the
backlight presence check during backlight setup.

Patch tested by author on Toshiba CB35.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=79813
Signed-off-by: Scot Doyle <lkml14@scotdoyle.com>
CC: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
[danvet: Add cc: stable because the regressing commit is in 3.15.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 3c58d0972e9d26507604fb6b038844bf9f3499bd..b91dfbe9fe8ed6865dd5ec35ce869f385ca17fc5 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -11248,6 +11248,9 @@ static struct intel_quirk intel_quirks[] = {
 
        /* Acer C720 and C720P Chromebooks (Celeron 2955U) have backlights */
        { 0x0a06, 0x1025, 0x0a11, quirk_backlight_present },
+
+       /* Toshiba CB35 Chromebook (Celeron 2955U) */
+       { 0x0a06, 0x1179, 0x0a88, quirk_backlight_present },
 };
 
 static void intel_init_quirks(struct drm_device *dev)