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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Hsin-Yi Wang <hsinyi@chromium.org>,
        Xin Ji <xji@analogixsemi.com>,
        Robert Foss <robert.foss@linaro.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.18 0420/1095] drm/bridge: anx7625: Fix NULL pointer crash when using edp-panel
Date:   Mon, 15 Aug 2022 19:56:59 +0200
Message-Id: <20220815180447.079124897@linuxfoundation.org>
In-Reply-To: <20220815180429.240518113@linuxfoundation.org>
References: <20220815180429.240518113@linuxfoundation.org>
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From: Hsin-Yi Wang <hsinyi@chromium.org>

[ Upstream commit dfb02eb6bdf84697dbadd69a7df12db612ce4ed0 ]

Move devm_of_dp_aux_populate_ep_devices() after pm runtime and i2c setup
to avoid NULL pointer crash.

edp-panel probe (generic_edp_panel_probe) calls pm_runtime_get_sync() to
read EDID. At this time, bridge should have pm runtime enabled and i2c
clients ready.

Fixes: adca62ec370c ("drm/bridge: anx7625: Support reading edid through aux channel")
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Reviewed-by: Xin Ji <xji@analogixsemi.com>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220706125254.2474095-4-hsinyi@chromium.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/bridge/analogix/anx7625.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
index 060849f8ad8b..c527a3a02eac 100644
--- a/drivers/gpu/drm/bridge/analogix/anx7625.c
+++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
@@ -2651,14 +2651,6 @@ static int anx7625_i2c_probe(struct i2c_client *client,
 	platform->aux.dev = dev;
 	platform->aux.transfer = anx7625_aux_transfer;
 	drm_dp_aux_init(&platform->aux);
-	devm_of_dp_aux_populate_ep_devices(&platform->aux);
-
-	ret = anx7625_parse_dt(dev, pdata);
-	if (ret) {
-		if (ret != -EPROBE_DEFER)
-			DRM_DEV_ERROR(dev, "fail to parse DT : %d\n", ret);
-		goto free_wq;
-	}
 
 	if (anx7625_register_i2c_dummy_clients(platform, client) != 0) {
 		ret = -ENOMEM;
@@ -2674,6 +2666,15 @@ static int anx7625_i2c_probe(struct i2c_client *client,
 	if (ret)
 		goto free_wq;
 
+	devm_of_dp_aux_populate_ep_devices(&platform->aux);
+
+	ret = anx7625_parse_dt(dev, pdata);
+	if (ret) {
+		if (ret != -EPROBE_DEFER)
+			DRM_DEV_ERROR(dev, "fail to parse DT : %d\n", ret);
+		goto free_wq;
+	}
+
 	if (!platform->pdata.low_power_mode) {
 		anx7625_disable_pd_protocol(platform);
 		pm_runtime_get_sync(dev);
-- 
2.35.1