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From:   Sankeerth Billakanti <quic_sbillaka@quicinc.com>
To:     <dri-devel@lists.freedesktop.org>, <linux-arm-msm@vger.kernel.org>,
        <freedreno@lists.freedesktop.org>, <linux-kernel@vger.kernel.org>,
        <devicetree@vger.kernel.org>
CC:     Sankeerth Billakanti <quic_sbillaka@quicinc.com>,
        <robdclark@gmail.com>, <seanpaul@chromium.org>,
        <swboyd@chromium.org>, <quic_kalyant@quicinc.com>,
        <quic_abhinavk@quicinc.com>, <dianders@chromium.org>,
        <quic_khsieh@quicinc.com>, <bjorn.andersson@linaro.org>,
        <sean@poorly.run>, <airlied@linux.ie>, <daniel@ffwll.ch>,
        <dmitry.baryshkov@linaro.org>, <quic_vproddut@quicinc.com>,
        <quic_aravindh@quicinc.com>, <steev@kali.org>
Subject: [PATCH v8 4/4] drm/msm/dp: Support the eDP modes given by panel
Date:   Thu, 21 Apr 2022 20:06:51 +0530
Message-ID: <1650551811-24319-5-git-send-email-quic_sbillaka@quicinc.com>
In-Reply-To: <1650551811-24319-1-git-send-email-quic_sbillaka@quicinc.com>
References: <1650551811-24319-1-git-send-email-quic_sbillaka@quicinc.com>
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The eDP controller does not have a reliable way keep panel
powered on to read the sink capabilities. So, the controller
driver cannot validate if a mode can be supported by the
source. We will rely on the panel driver to populate only
the supported modes for now.

Signed-off-by: Sankeerth Billakanti <quic_sbillaka@quicinc.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
---
Changes in v8:
  - add the drm/msm/dp tag in the commit title

 drivers/gpu/drm/msm/dp/dp_display.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index 86948d6..7d71bdc 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -998,6 +998,14 @@ enum drm_mode_status dp_bridge_mode_valid(struct drm_bridge *bridge,
 		return -EINVAL;
 	}
 
+	/*
+	 * The eDP controller currently does not have a reliable way of
+	 * enabling panel power to read sink capabilities. So, we rely
+	 * on the panel driver to populate only supported modes for now.
+	 */
+	if (dp->is_edp)
+		return MODE_OK;
+
 	if ((dp->max_pclk_khz <= 0) ||
 			(dp->max_pclk_khz > DP_MAX_PIXEL_CLK_KHZ) ||
 			(mode->clock > dp->max_pclk_khz))
-- 
2.7.4