diff options
| author | Puthikorn Voravootivat <puthik@chromium.org> | 2017-05-11 16:02:18 -0700 |
|---|---|---|
| committer | Jani Nikula <jani.nikula@intel.com> | 2017-05-12 15:47:09 +0300 |
| commit | 73ab484c90f5a696a6552c82f5d64b13303c0813 (patch) | |
| tree | 9db2eda615cdb35a629a163dbcad3fa7ddbedcee /drivers/gpu/drm/i915/intel_dp_aux_backlight.c | |
| parent | a644ca9bcdac3b9e9f0fd2726c9198e85cecfbee (diff) | |
drm/i915: Correctly enable backlight brightness adjustment via DPCD
intel_dp_aux_enable_backlight() assumed that the register
BACKLIGHT_BRIGHTNESS_CONTROL_MODE can only has value 01
(DP_EDP_BACKLIGHT_CONTROL_MODE_PRESET) when initialize.
This patch fixed that by handling all cases of that register.
Signed-off-by: Puthikorn Voravootivat <puthik@chromium.org>
Reviewed-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170511230225.142870-3-puthik@chromium.org
Diffstat (limited to 'drivers/gpu/drm/i915/intel_dp_aux_backlight.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_dp_aux_backlight.c | 33 |
1 files changed, 27 insertions, 6 deletions
diff --git a/drivers/gpu/drm/i915/intel_dp_aux_backlight.c b/drivers/gpu/drm/i915/intel_dp_aux_backlight.c index 341bf2cb0c25..870c03fc0f3a 100644 --- a/drivers/gpu/drm/i915/intel_dp_aux_backlight.c +++ b/drivers/gpu/drm/i915/intel_dp_aux_backlight.c @@ -97,15 +97,36 @@ static void intel_dp_aux_enable_backlight(struct intel_connector *connector) { struct intel_dp *intel_dp = enc_to_intel_dp(&connector->encoder->base); uint8_t dpcd_buf = 0; + uint8_t edp_backlight_mode = 0; set_aux_backlight_enable(intel_dp, true); - if ((drm_dp_dpcd_readb(&intel_dp->aux, - DP_EDP_BACKLIGHT_MODE_SET_REGISTER, &dpcd_buf) == 1) && - ((dpcd_buf & DP_EDP_BACKLIGHT_CONTROL_MODE_MASK) == - DP_EDP_BACKLIGHT_CONTROL_MODE_PRESET)) - drm_dp_dpcd_writeb(&intel_dp->aux, DP_EDP_BACKLIGHT_MODE_SET_REGISTER, - (dpcd_buf | DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD)); + if (drm_dp_dpcd_readb(&intel_dp->aux, + DP_EDP_BACKLIGHT_MODE_SET_REGISTER, &dpcd_buf) != 1) { + DRM_DEBUG_KMS("Failed to read DPCD register 0x%x\n", + DP_EDP_BACKLIGHT_MODE_SET_REGISTER); + return; + } + + edp_backlight_mode = dpcd_buf & DP_EDP_BACKLIGHT_CONTROL_MODE_MASK; + + switch (edp_backlight_mode) { + case DP_EDP_BACKLIGHT_CONTROL_MODE_PWM: + case DP_EDP_BACKLIGHT_CONTROL_MODE_PRESET: + case DP_EDP_BACKLIGHT_CONTROL_MODE_PRODUCT: + dpcd_buf &= ~DP_EDP_BACKLIGHT_CONTROL_MODE_MASK; + dpcd_buf |= DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD; + if (drm_dp_dpcd_writeb(&intel_dp->aux, + DP_EDP_BACKLIGHT_MODE_SET_REGISTER, dpcd_buf) < 0) { + DRM_DEBUG_KMS("Failed to write aux backlight mode\n"); + } + break; + + /* Do nothing when it is already DPCD mode */ + case DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD: + default: + break; + } } static void intel_dp_aux_disable_backlight(struct intel_connector *connector) |