From f7302e98f8e2dc8b6574a4f225e674b5bd55bf31 Mon Sep 17 00:00:00 2001
From: Sankeerth Billakanti <quic_sbillaka@quicinc.com>
Date: Mon, 25 Apr 2022 17:14:32 +0530
Subject: drm/msm/dp: Support the eDP modes given by panel
Git-commit: 3bc965f15e96b51c7e683eaf72e93a2dc6dac471
Patch-mainline: v5.19-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

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>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Patchwork: https://patchwork.freedesktop.org/patch/483313/
Link: https://lore.kernel.org/r/1650887072-16652-5-git-send-email-quic_sbillaka@quicinc.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 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 16b93151b3b3..f633306f27a0 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -980,6 +980,14 @@ 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 (mode->clock > DP_MAX_PIXEL_CLK_KHZ)
 		return MODE_BAD;
 
-- 
2.38.1