linux-kernel - [PATCH v4 06/13] drm/meson: fix unbind path if HDMI fails to bind

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Message-Id: <20230512-amlogic-v6-4-upstream-dsi-ccf-vim3-v4-6-2592c29ea263@linaro.org>
Date:   Fri, 12 May 2023 15:11:37 +0200
From:   Neil Armstrong <neil.armstrong@...aro.org>
To:     Jerome Brunet <jbrunet@...libre.com>,
        Michael Turquette <mturquette@...libre.com>,
        Stephen Boyd <sboyd@...nel.org>,
        Kevin Hilman <khilman@...libre.com>,
        Martin Blumenstingl <martin.blumenstingl@...glemail.com>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Conor Dooley <conor+dt@...nel.org>,
        David Airlie <airlied@...il.com>,
        Daniel Vetter <daniel@...ll.ch>,
        Philipp Zabel <p.zabel@...gutronix.de>,
        Vinod Koul <vkoul@...nel.org>,
        Kishon Vijay Abraham I <kishon@...nel.org>,
        Sam Ravnborg <sam@...nborg.org>
Cc:     Nicolas Belin <nbelin@...libre.com>,
        linux-amlogic@...ts.infradead.org, linux-clk@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        devicetree@...r.kernel.org, dri-devel@...ts.freedesktop.org,
        linux-phy@...ts.infradead.org,
        Neil Armstrong <neil.armstrong@...aro.org>
Subject: [PATCH v4 06/13] drm/meson: fix unbind path if HDMI fails to bind

If the case the HDMI controller fails to bind, we try to unbind
all components before calling drm_dev_put() which makes drm_bridge_detach()
crash because unbinding the HDMI controller frees the bridge memory.

The solution is the unbind all components at the end like in the remove
path.

Signed-off-by: Neil Armstrong <neil.armstrong@...aro.org>
---
 drivers/gpu/drm/meson/meson_drv.c | 23 ++++++++++++++---------
 1 file changed, 14 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/meson/meson_drv.c b/drivers/gpu/drm/meson/meson_drv.c
index bb72fda9106d..a30d61f1c817 100644
--- a/drivers/gpu/drm/meson/meson_drv.c
+++ b/drivers/gpu/drm/meson/meson_drv.c
@@ -316,32 +316,34 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)
 		goto exit_afbcd;
 
 	if (has_components) {
-		ret = component_bind_all(drm->dev, drm);
+		ret = component_bind_all(dev, drm);
 		if (ret) {
 			dev_err(drm->dev, "Couldn't bind all components\n");
+			/* Do not try to unbind */
+			has_components = false;
 			goto exit_afbcd;
 		}
 	}
 
 	ret = meson_encoder_hdmi_init(priv);
 	if (ret)
-		goto unbind_all;
+		goto exit_afbcd;
 
 	ret = meson_plane_create(priv);
 	if (ret)
-		goto unbind_all;
+		goto exit_afbcd;
 
 	ret = meson_overlay_create(priv);
 	if (ret)
-		goto unbind_all;
+		goto exit_afbcd;
 
 	ret = meson_crtc_create(priv);
 	if (ret)
-		goto unbind_all;
+		goto exit_afbcd;
 
 	ret = request_irq(priv->vsync_irq, meson_irq, 0, drm->driver->name, drm);
 	if (ret)
-		goto unbind_all;
+		goto exit_afbcd;
 
 	drm_mode_config_reset(drm);
 
@@ -359,15 +361,18 @@ static int meson_drv_bind_master(struct device *dev, bool has_components)
 
 uninstall_irq:
 	free_irq(priv->vsync_irq, drm);
-unbind_all:
-	if (has_components)
-		component_unbind_all(drm->dev, drm);
 exit_afbcd:
 	if (priv->afbcd.ops)
 		priv->afbcd.ops->exit(priv);
 free_drm:
 	drm_dev_put(drm);
 
+	meson_encoder_hdmi_remove(priv);
+	meson_encoder_cvbs_remove(priv);
+
+	if (has_components)
+		component_unbind_all(dev, drm);
+
 	return ret;
 }
 

-- 
2.34.1