Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Kuogee Hsieh <quic_khsieh@quicinc.com>
To:     <robdclark@gmail.com>, <sean@poorly.run>, <swboyd@chromium.org>,
        <vkoul@kernel.org>, <daniel@ffwll.ch>, <airlied@linux.ie>,
        <agross@kernel.org>, <dmitry.baryshkov@linaro.org>,
        <bjorn.andersson@linaro.org>
CC:     <quic_abhinavk@quicinc.com>, <aravindh@codeaurora.org>,
        <quic_khsieh@quicinc.com>, <freedreno@lists.freedesktop.org>,
        <dri-devel@lists.freedesktop.org>, <linux-arm-msm@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
Subject: [PATCH v2] drm/msm/dp: always add fail-safe mode into connector mode list
Date:   Mon, 24 Jan 2022 15:17:54 -0800
Message-ID: <1643066274-25814-1-git-send-email-quic_khsieh@quicinc.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

Some of DP link compliant test expects to return fail-safe mode
if prefer detailed timing mode can not be supported by mainlink's
lane and rate after link training. Therefore add fail-safe mode
into connector mode list as backup mode. This patch fixes test
case 4.2.2.1.

Changes in v2:
-- add Fixes text string

Fixes: 4b85d405cfe9 ( "drm/msm/dp: reduce link rate if failed at link training 1")
Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
---
 drivers/gpu/drm/msm/dp/dp_panel.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/msm/dp/dp_panel.c b/drivers/gpu/drm/msm/dp/dp_panel.c
index 71db10c..f141872 100644
--- a/drivers/gpu/drm/msm/dp/dp_panel.c
+++ b/drivers/gpu/drm/msm/dp/dp_panel.c
@@ -212,6 +212,11 @@ int dp_panel_read_sink_caps(struct dp_panel *dp_panel,
 		if (drm_add_modes_noedid(connector, 640, 480))
 			drm_set_preferred_mode(connector, 640, 480);
 		mutex_unlock(&connector->dev->mode_config.mutex);
+	} else {
+		/* always add fail-safe mode as backup mode */
+		mutex_lock(&connector->dev->mode_config.mutex);
+		drm_add_modes_noedid(connector, 640, 480);
+		mutex_unlock(&connector->dev->mode_config.mutex);
 	}
 
 	if (panel->aux_cfg_update_done) {
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project