In preparation to handle refcounting of the out_bridge, we need to ensure
the out_bridge pointer contains either a valid bridge pointer or NULL, not
an ERR_PTR. Otherwise calls such as drm_bridge_get/put() would try to
redeference an ERR_PTR.

As a preliminary cleanup, add a temporary local 'next_bridge' pointer and
only copy it in dsi->out_bridge when returning successfully.

Signed-off-by: Luca Ceresoli <[email protected]>
---
 drivers/gpu/drm/bridge/samsung-dsim.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c 
b/drivers/gpu/drm/bridge/samsung-dsim.c
index eabc4c32f6ab..b3003aa49dc3 100644
--- a/drivers/gpu/drm/bridge/samsung-dsim.c
+++ b/drivers/gpu/drm/bridge/samsung-dsim.c
@@ -1886,6 +1886,7 @@ static int samsung_dsim_host_attach(struct mipi_dsi_host 
*host,
 {
        struct samsung_dsim *dsi = host_to_dsi(host);
        const struct samsung_dsim_plat_data *pdata = dsi->plat_data;
+       struct drm_bridge *next_bridge;
        struct device *dev = dsi->dev;
        struct device_node *np = dev->of_node;
        struct device_node *remote;
@@ -1924,17 +1925,17 @@ static int samsung_dsim_host_attach(struct 
mipi_dsi_host *host,
 
        panel = of_drm_find_panel(remote);
        if (!IS_ERR(panel)) {
-               dsi->out_bridge = devm_drm_panel_bridge_add(dev, panel);
+               next_bridge = devm_drm_panel_bridge_add(dev, panel);
        } else {
-               dsi->out_bridge = of_drm_find_bridge(remote);
-               if (!dsi->out_bridge)
-                       dsi->out_bridge = ERR_PTR(-EINVAL);
+               next_bridge = of_drm_find_bridge(remote);
+               if (!next_bridge)
+                       next_bridge = ERR_PTR(-EINVAL);
        }
 
        of_node_put(remote);
 
-       if (IS_ERR(dsi->out_bridge)) {
-               ret = PTR_ERR(dsi->out_bridge);
+       if (IS_ERR(next_bridge)) {
+               ret = PTR_ERR(next_bridge);
                DRM_DEV_ERROR(dev, "failed to find the bridge: %d\n", ret);
                return ret;
        }
@@ -1967,6 +1968,7 @@ static int samsung_dsim_host_attach(struct mipi_dsi_host 
*host,
        dsi->lanes = device->lanes;
        dsi->format = device->format;
        dsi->mode_flags = device->mode_flags;
+       dsi->out_bridge = next_bridge;
 
        return 0;
 }

-- 
2.52.0

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