On Thu, 22 Aug 2019 03:17:32 +0300 Laurent Pinchart laurent.pinchart@ideasonboard.com wrote:
Hi Boris,
Thank you for the patch.
On Thu, Aug 08, 2019 at 05:11:44PM +0200, Boris Brezillon wrote:
Will be useful for bridge drivers that want to do bus format negotiation with their neighbours.
Signed-off-by: Boris Brezillon boris.brezillon@collabora.com
drivers/gpu/drm/drm_bridge.c | 19 +++++++++++++++++++ include/drm/drm_bridge.h | 2 ++ 2 files changed, 21 insertions(+)
diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c index dcad661daa74..9efb27087e70 100644 --- a/drivers/gpu/drm/drm_bridge.c +++ b/drivers/gpu/drm/drm_bridge.c @@ -271,6 +271,25 @@ drm_bridge_chain_get_next_bridge(struct drm_bridge *bridge) } EXPORT_SYMBOL(drm_bridge_chain_get_next_bridge);
+/**
- drm_bridge_chain_get_prev_bridge() - Get the previous bridge in the chain
- @bridge: bridge object
- RETURNS:
- the previous bridge in the chain, or NULL if there's @bridge is the
- last.
Did you mean "if the @bridge is the first" ?
Yes, sorry about that, I meant "if @bridge is the first", indeed.
- */
+struct drm_bridge * +drm_bridge_chain_get_prev_bridge(struct drm_bridge *bridge) +{
- if (!bridge || !bridge->encoder ||
Do we really need to protect against !bridge and !bridge->encoder, can that happen ?
Maybe not.
Especially !bridge, are there use cases for potentially calling this function (and the other list traversal helpers in your previous patches) with a NULL bridge ?
I think this checks was done when bridge iteration was based on recursivity, which is no longer the case.
list_is_first(&bridge->encoder->bridge_chain, &bridge->chain_node))return NULL;- return list_prev_entry(bridge, chain_node);
+} +EXPORT_SYMBOL(drm_bridge_chain_get_prev_bridge);
/**
- DOC: bridge callbacks
diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h index 5d8fe3709bde..2f69adb7b0f3 100644 --- a/include/drm/drm_bridge.h +++ b/include/drm/drm_bridge.h @@ -485,6 +485,8 @@ struct drm_bridge * drm_bridge_chain_get_last_bridge(struct drm_encoder *encoder); struct drm_bridge * drm_bridge_chain_get_next_bridge(struct drm_bridge *bridge); +struct drm_bridge * +drm_bridge_chain_get_prev_bridge(struct drm_bridge *bridge); bool drm_bridge_chain_mode_fixup(struct drm_encoder *encoder, const struct drm_display_mode *mode, struct drm_display_mode *adjusted_mode);