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| author | Luca Ceresoli <luca.ceresoli@bootlin.com> | 2026-05-11 19:40:15 +0300 |
|---|---|---|
| committer | Luca Ceresoli <luca.ceresoli@bootlin.com> | 2026-05-19 11:57:26 +0300 |
| commit | 0d5da248ea2d7802a5055ab6762340ac870bd0ee (patch) | |
| tree | 0e25a5d2f782d74a16c20ed9ffd1db5572e114f1 | |
| parent | 62f1a79e1b004b250e68e10c32a29fd954fc9725 (diff) | |
| download | linux-0d5da248ea2d7802a5055ab6762340ac870bd0ee.tar.xz | |
drm: of: forbid bridge-only calls to drm_of_find_panel_or_bridge()
Up to now drm_of_find_panel_or_bridge() can be called with a bridge pointer
only, a panel pointer only, or both a bridge and a panel pointers. The
logic to handle all the three cases is somewhat complex to read however.
Now all bridge-only callers have been converted to
of_drm_get_bridge_by_endpoint(), which is simpler and handles bridge
refcounting. So forbid new bridge-only users by mandating a non-NULL panel
pointer in the docs and in the sanity checks along with a warning.
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Link: https://patch.msgid.link/20260511-drm-bridge-alloc-getput-panel_or_bridge-v6-11-f61c9e498b3f@bootlin.com
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
| -rw-r--r-- | drivers/gpu/drm/drm_of.c | 26 |
1 files changed, 12 insertions, 14 deletions
diff --git a/drivers/gpu/drm/drm_of.c b/drivers/gpu/drm/drm_of.c index ef6b09316963..d03ada82eac9 100644 --- a/drivers/gpu/drm/drm_of.c +++ b/drivers/gpu/drm/drm_of.c @@ -225,15 +225,15 @@ EXPORT_SYMBOL_GPL(drm_of_encoder_active_endpoint); * @np: device tree node containing encoder output ports * @port: port in the device tree node * @endpoint: endpoint in the device tree node - * @panel: pointer to hold returned drm_panel + * @panel: pointer to hold returned drm_panel, must not be NULL * @bridge: pointer to hold returned drm_bridge * * Given a DT node's port and endpoint number, find the connected node and - * return either the associated struct drm_panel or drm_bridge device. Either - * @panel or @bridge must not be NULL. + * return either the associated struct drm_panel or drm_bridge device. * * This function is deprecated and should not be used in new drivers. Use - * devm_drm_of_get_bridge() instead. + * of_drm_get_bridge_by_endpoint() instead when not looking for a panel, or + * devm_drm_of_get_bridge() otherwise. * * Returns zero if successful, or one of the standard error codes if it fails. */ @@ -245,10 +245,10 @@ int drm_of_find_panel_or_bridge(const struct device_node *np, int ret = -EPROBE_DEFER; struct device_node *remote; - if (!panel && !bridge) + if (WARN_ON(!panel)) return -EINVAL; - if (panel) - *panel = NULL; + + *panel = NULL; /* * of_graph_get_remote_node() produces a noisy error message if port @@ -263,13 +263,11 @@ int drm_of_find_panel_or_bridge(const struct device_node *np, if (!remote) return -ENODEV; - if (panel) { - *panel = of_drm_find_panel(remote); - if (!IS_ERR(*panel)) - ret = 0; - else - *panel = NULL; - } + *panel = of_drm_find_panel(remote); + if (!IS_ERR(*panel)) + ret = 0; + else + *panel = NULL; if (bridge) { if (ret) { |