[Intel-gfx] [PATCH] CHROMIUM: drm/i915: Initialize the backlight when reported max is 0

[james.ausmus at intel.com]

From: Stéphane Marchesin <marcheu at chromium.org>

The i915 driver stopped doing this in 3.8. Chrome OS machines rely
on this initialization since they don't have a VBIOS.

BUG=chromium:242552
TEST=by hand on a stumpy which doesn't run the vbios: the backlight is non-zero

Change-Id: Ia76238a1e93e89a4f1434e88edb431225062f0e1
Reviewed-on: https://gerrit.chromium.org/gerrit/56134
Tested-by: Stéphane Marchesin <marcheu at chromium.org>
Reviewed-by: Sonny Rao <sonnyrao at chromium.org>
Commit-Queue: Stéphane Marchesin <marcheu at chromium.org>
---
 drivers/gpu/drm/i915/intel_panel.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c
index abc7064..a3d87a9 100644
--- a/drivers/gpu/drm/i915/intel_panel.c
+++ b/drivers/gpu/drm/i915/intel_panel.c
@@ -508,11 +508,7 @@ int intel_panel_setup_backlight(struct drm_connector *connector)
 
 	memset(&props, 0, sizeof(props));
 	props.type = BACKLIGHT_RAW;
-	props.max_brightness = _intel_panel_get_max_backlight(dev);
-	if (props.max_brightness == 0) {
-		DRM_DEBUG_DRIVER("Failed to get maximum backlight value\n");
-		return -ENODEV;
-	}
+	props.max_brightness = intel_panel_get_max_backlight(dev);
 	dev_priv->backlight =
 		backlight_device_register("intel_backlight",
 					  &connector->kdev, dev,
-- 
1.8.3.2