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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, Brian Norris <briannorris@chromium.org>,
        Sam Ravnborg <sam@ravnborg.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.10 046/563] drm/panel: innolux-p079zca: Delete panel on attach() failure
Date:   Mon, 24 Jan 2022 19:36:51 +0100
Message-Id: <20220124184026.007769115@linuxfoundation.org>
In-Reply-To: <20220124184024.407936072@linuxfoundation.org>
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From: Brian Norris <briannorris@chromium.org>

[ Upstream commit 32a267e9c057e1636e7afdd20599aa5741a73079 ]

If we fail to attach (e.g., because 1 of 2 dual-DSI controllers aren't
ready), we leave a dangling drm_panel reference to freed memory. Clean
that up on failure.

This problem exists since the driver's introduction, but is especially
relevant after refactored for dual-DSI variants.

Fixes: 14c8f2e9f8ea ("drm/panel: add Innolux P079ZCA panel driver")
Fixes: 7ad4e4636c54 ("drm/panel: p079zca: Refactor panel driver to support multiple panels")
Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210923173336.2.I9023cf8811a3abf4964ed84eb681721d8bb489d6@changeid
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/panel/panel-innolux-p079zca.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/panel/panel-innolux-p079zca.c b/drivers/gpu/drm/panel/panel-innolux-p079zca.c
index aea3162253914..f194b62e290ca 100644
--- a/drivers/gpu/drm/panel/panel-innolux-p079zca.c
+++ b/drivers/gpu/drm/panel/panel-innolux-p079zca.c
@@ -484,6 +484,7 @@ static void innolux_panel_del(struct innolux_panel *innolux)
 static int innolux_panel_probe(struct mipi_dsi_device *dsi)
 {
 	const struct panel_desc *desc;
+	struct innolux_panel *innolux;
 	int err;
 
 	desc = of_device_get_match_data(&dsi->dev);
@@ -495,7 +496,14 @@ static int innolux_panel_probe(struct mipi_dsi_device *dsi)
 	if (err < 0)
 		return err;
 
-	return mipi_dsi_attach(dsi);
+	err = mipi_dsi_attach(dsi);
+	if (err < 0) {
+		innolux = mipi_dsi_get_drvdata(dsi);
+		innolux_panel_del(innolux);
+		return err;
+	}
+
+	return 0;
 }
 
 static int innolux_panel_remove(struct mipi_dsi_device *dsi)
-- 
2.34.1