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| author | Imre Deak <imre.deak@intel.com> | 2015-12-01 10:23:52 +0200 |
|---|---|---|
| committer | Jani Nikula <jani.nikula@intel.com> | 2015-12-02 10:10:39 +0200 |
| commit | d965e7ac7a196c27e299c598bcb678ab71132dc1 (patch) | |
| tree | f61597b1defdafd0319ece60f218ca6f44676978 /drivers/gpu/drm/i915/intel_pm.c | |
| parent | 5075222b04a28bff6bf1c66a7baced787be6b6de (diff) | |
| download | op-kernel-dev-d965e7ac7a196c27e299c598bcb678ab71132dc1.zip op-kernel-dev-d965e7ac7a196c27e299c598bcb678ab71132dc1.tar.gz | |
drm/i915/bxt: backlight clock gating workaround
Per bspec, "Backlight PWM may stop in the asserted state, causing
backlight to stay fully on. WA: Before disabling PWM, set CLKGATE_DIS_0
0x46530 bit 13 PWM1 Gating Dis (for PWM1) or bit 14 PWM2 Gating Dis (for
PWM2). The bits can remain set without harm." (There's no workaround
name for this.)
This fixes some Broxton backlight issues.
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
[Jani: cleanup & commit message]
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1448958232-26520-3-git-send-email-jani.nikula@intel.com
Diffstat (limited to 'drivers/gpu/drm/i915/intel_pm.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_pm.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index 96f45d7..612a8b4 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -66,6 +66,14 @@ static void bxt_init_clock_gating(struct drm_device *dev) */ I915_WRITE(GEN8_UCGCTL6, I915_READ(GEN8_UCGCTL6) | GEN8_HDCUNIT_CLOCK_GATE_DISABLE_HDCREQ); + + /* + * Wa: Backlight PWM may stop in the asserted state, causing backlight + * to stay fully on. + */ + if (IS_BXT_REVID(dev_priv, BXT_REVID_B0, REVID_FOREVER)) + I915_WRITE(GEN9_CLKGATE_DIS_0, I915_READ(GEN9_CLKGATE_DIS_0) | + PWM1_GATING_DIS | PWM2_GATING_DIS); } static void i915_pineview_get_mem_freq(struct drm_device *dev) |
