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From: Puthikorn Voravootivat <puthik@chromium.org>
To: intel-gfx@lists.freedesktop.org,
	Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Cc: Puthikorn Voravootivat <puthik@chromium.org>,
	dri-devel@lists.freedesktop.org
Subject: [PATCH v6 2/9] drm/i915: Correctly enable backlight brightness adjustment via DPCD
Date: Tue,  9 May 2017 16:40:45 -0700	[thread overview]
Message-ID: <20170509234052.189575-3-puthik@chromium.org> (raw)
In-Reply-To: <20170509234052.189575-1-puthik@chromium.org>

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>
---
 drivers/gpu/drm/i915/intel_dp_aux_backlight.c | 33 ++++++++++++++++++++++-----
 1 file 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)
-- 
2.13.0.rc2.291.g57267f2277-goog

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  parent reply	other threads:[~2017-05-09 23:41 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-05-09 23:40 [PATCH v6 0/9] Enhancement to intel_dp_aux_backlight driver Puthikorn Voravootivat
2017-05-09 23:40 ` [PATCH v6 1/9] drm/i915: Fix cap check for " Puthikorn Voravootivat
2017-05-11  0:14   ` Pandiyan, Dhinakaran
2017-05-09 23:40 ` Puthikorn Voravootivat [this message]
2017-05-09 23:40 ` [PATCH v6 3/9] drm/i915: Drop AUX backlight enable check for backlight control Puthikorn Voravootivat
2017-05-11  0:39   ` Pandiyan, Dhinakaran
2017-05-11 21:01     ` Puthikorn Voravootivat
2017-05-09 23:40 ` [PATCH v6 4/9] drm/i915: Allow choosing how to adjust brightness if both supported Puthikorn Voravootivat
2017-05-11  0:50   ` Pandiyan, Dhinakaran
2017-05-09 23:40 ` [PATCH v6 5/9] drm/i915: Set backlight mode before enable backlight Puthikorn Voravootivat
2017-05-09 23:40 ` [PATCH v6 6/9] drm/i915: Support dynamic backlight via DPCD register Puthikorn Voravootivat
2017-05-11  5:45   ` Pandiyan, Dhinakaran
2017-05-09 23:40 ` [PATCH v6 7/9] drm/i915: Restore brightness level in aux backlight driver Puthikorn Voravootivat
2017-05-09 23:40 ` [PATCH v6 8/9] drm: Add definition for eDP backlight frequency Puthikorn Voravootivat
2017-05-11  1:09   ` Pandiyan, Dhinakaran
2017-05-09 23:40 ` [PATCH v6 9/9] drm/i915: Set PWM divider to match desired frequency in vbt Puthikorn Voravootivat
2017-05-10  7:45 ` ✗ Fi.CI.BAT: failure for Enhancement to intel_dp_aux_backlight driver (rev5) Patchwork

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