diff options
| author | Jani Nikula <jani.nikula@intel.com> | 2012-09-03 13:25:12 (GMT) |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2012-09-03 18:42:10 (GMT) |
| commit | 28dcc2d60cb570d9f549c329b2f51400553412a1 (patch) | |
| tree | ec327dfe215656bd0aa84afe64967248a85ecd8c /drivers/gpu | |
| parent | fcbc50da7753b210b4442ca9abc4efbd4e481f6e (diff) | |
| download | linux-28dcc2d60cb570d9f549c329b2f51400553412a1.tar.xz | |
drm/i915: do not expose a dysfunctional backlight interface to userspace
Previously intel_panel_setup_backlight() would create a sysfs backlight
interface with max brightness of 1 if it was unable to figure out the max
backlight brightness. This rendered the backlight interface useless.
Do not create a dysfunctional backlight interface to begin with.
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Tested-by: David Woodhouse <David.Woodhouse@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_panel.c | 31 |
1 files changed, 22 insertions, 9 deletions
diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c index 3df4f5f..e019b23 100644 --- a/drivers/gpu/drm/i915/intel_panel.c +++ b/drivers/gpu/drm/i915/intel_panel.c @@ -162,19 +162,12 @@ static u32 i915_read_blc_pwm_ctl(struct drm_i915_private *dev_priv) return val; } -u32 intel_panel_get_max_backlight(struct drm_device *dev) +static u32 _intel_panel_get_max_backlight(struct drm_device *dev) { struct drm_i915_private *dev_priv = dev->dev_private; u32 max; max = i915_read_blc_pwm_ctl(dev_priv); - if (max == 0) { - /* XXX add code here to query mode clock or hardware clock - * and program max PWM appropriately. - */ - pr_warn_once("fixme: max PWM is zero\n"); - return 1; - } if (HAS_PCH_SPLIT(dev)) { max >>= 16; @@ -188,6 +181,22 @@ u32 intel_panel_get_max_backlight(struct drm_device *dev) max *= 0xff; } + return max; +} + +u32 intel_panel_get_max_backlight(struct drm_device *dev) +{ + u32 max; + + max = _intel_panel_get_max_backlight(dev); + if (max == 0) { + /* XXX add code here to query mode clock or hardware clock + * and program max PWM appropriately. + */ + pr_warn_once("fixme: max PWM is zero\n"); + return 1; + } + DRM_DEBUG_DRIVER("max backlight PWM = %d\n", max); return max; } @@ -424,7 +433,11 @@ int intel_panel_setup_backlight(struct drm_device *dev) memset(&props, 0, sizeof(props)); props.type = BACKLIGHT_RAW; - props.max_brightness = intel_panel_get_max_backlight(dev); + props.max_brightness = _intel_panel_get_max_backlight(dev); + if (props.max_brightness == 0) { + DRM_ERROR("Failed to get maximum backlight value\n"); + return -ENODEV; + } dev_priv->backlight = backlight_device_register("intel_backlight", &connector->kdev, dev, |