linux-kernel - [PATCH AUTOSEL 5.4 268/330] drm/exynos: dsi: Remove bridge node reference in error handling path in probe function

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Message-Id: <20200918020110.2063155-268-sashal@kernel.org>
Date:   Thu, 17 Sep 2020 22:00:08 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Christophe JAILLET <christophe.jaillet@...adoo.fr>,
        Inki Dae <inki.dae@...sung.com>,
        Sasha Levin <sashal@...nel.org>,
        dri-devel@...ts.freedesktop.org,
        linux-arm-kernel@...ts.infradead.org,
        linux-samsung-soc@...r.kernel.org
Subject: [PATCH AUTOSEL 5.4 268/330] drm/exynos: dsi: Remove bridge node reference in error handling path in probe function

From: Christophe JAILLET <christophe.jaillet@...adoo.fr>

[ Upstream commit 547a7348633b1f9923551f94ac3157a613d2c9f2 ]

'exynos_dsi_parse_dt()' takes a reference to 'dsi->in_bridge_node'.
This must be released in the error handling path.

In order to do that, add an error handling path and move the
'exynos_dsi_parse_dt()' call from the beginning to the end of the probe
function to ease the error handling path.
This function only sets some variables which are used only in the
'transfer' function.

The call chain is:
   .transfer
    --> exynos_dsi_host_transfer
      --> exynos_dsi_init
        --> exynos_dsi_enable_clock  (use burst_clk_rate and esc_clk_rate)
          --> exynos_dsi_set_pll     (use pll_clk_rate)

While at it, also handle cases where 'component_add()' fails.

This patch is similar to commit 70505c2ef94b ("drm/exynos: dsi: Remove bridge node reference in removal")
which fixed the issue in the remove function.

Signed-off-by: Christophe JAILLET <christophe.jaillet@...adoo.fr>
Signed-off-by: Inki Dae <inki.dae@...sung.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/gpu/drm/exynos/exynos_drm_dsi.c | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_dsi.c b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
index 8ed94c9948008..b83acd696774b 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_dsi.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
@@ -1741,10 +1741,6 @@ static int exynos_dsi_probe(struct platform_device *pdev)
 	dsi->dev = dev;
 	dsi->driver_data = of_device_get_match_data(dev);
 
-	ret = exynos_dsi_parse_dt(dsi);
-	if (ret)
-		return ret;
-
 	dsi->supplies[0].supply = "vddcore";
 	dsi->supplies[1].supply = "vddio";
 	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(dsi->supplies),
@@ -1805,11 +1801,25 @@ static int exynos_dsi_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	ret = exynos_dsi_parse_dt(dsi);
+	if (ret)
+		return ret;
+
 	platform_set_drvdata(pdev, &dsi->encoder);
 
 	pm_runtime_enable(dev);
 
-	return component_add(dev, &exynos_dsi_component_ops);
+	ret = component_add(dev, &exynos_dsi_component_ops);
+	if (ret)
+		goto err_disable_runtime;
+
+	return 0;
+
+err_disable_runtime:
+	pm_runtime_disable(dev);
+	of_node_put(dsi->in_bridge_node);
+
+	return ret;
 }
 
 static int exynos_dsi_remove(struct platform_device *pdev)
-- 
2.25.1