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| author | Jani Nikula <jani.nikula@intel.com> | 2015-10-28 11:57:09 (GMT) |
|---|---|---|
| committer | Jani Nikula <jani.nikula@intel.com> | 2015-10-28 17:10:37 (GMT) |
| commit | 6675bce251b6ec20ec09c07e941d9f664be4ae58 (patch) | |
| tree | 64ddaff8f400d6b88e81e943644411981401cc2f /drivers/gpu/drm/i915/intel_panel.c | |
| parent | 5a37ed0a9eda5fd77a4cc92c6e46b6f6e8db873d (diff) | |
| download | linux-6675bce251b6ec20ec09c07e941d9f664be4ae58.tar.xz | |
drm/i915: disable CPU PWM also on LPT/SPT backlight disable
Although we don't support or enable CPU PWM with LPT/SPT based systems,
it may have been enabled prior to loading the driver. Disable the CPU
PWM on LPT/SPT backlight disable to avoid warnings on LCPLL disable.
The issue has been present on BDW since BDW enabling, but was recently
introduced on HSW with
commit 437b15b8017e0d946453c10794b0c5d4591cf180
Author: Jani Nikula <jani.nikula@intel.com>
Date: Fri Sep 4 16:55:13 2015 +0300
drm/i915: use pch backlight override on hsw too
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reference: http://mid.gmane.org/87y4frhwsn.fsf@yhuang-dev.intel.com
Reported-by: kernel test robot <ying.huang@intel.com>
Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1446033429-8006-1-git-send-email-jani.nikula@intel.com
Diffstat (limited to 'drivers/gpu/drm/i915/intel_panel.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_panel.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c index b05c6d9..a24df35 100644 --- a/drivers/gpu/drm/i915/intel_panel.c +++ b/drivers/gpu/drm/i915/intel_panel.c @@ -732,6 +732,20 @@ static void lpt_disable_backlight(struct intel_connector *connector) intel_panel_actually_set_backlight(connector, 0); + /* + * Although we don't support or enable CPU PWM with LPT/SPT based + * systems, it may have been enabled prior to loading the + * driver. Disable to avoid warnings on LCPLL disable. + * + * This needs rework if we need to add support for CPU PWM on PCH split + * platforms. + */ + tmp = I915_READ(BLC_PWM_CPU_CTL2); + if (tmp & BLM_PWM_ENABLE) { + DRM_DEBUG_KMS("cpu backlight was enabled, disabling\n"); + I915_WRITE(BLC_PWM_CPU_CTL2, tmp & ~BLM_PWM_ENABLE); + } + tmp = I915_READ(BLC_PWM_PCH_CTL1); I915_WRITE(BLC_PWM_PCH_CTL1, tmp & ~BLM_PCH_PWM_ENABLE); } |