kernel/drivers/media/mc/mc-entity.c, branch linux-rolling-stable

media: mc: Improve unconnected pads debugging message in link exploration

2025-08-25T13:40:44Z

When exploring links, a message is printed to indicate unconnected pads being added. The message prints the entity name only. Print the origin pad number as well to help with debugging pipeline start issues. While at it, get the entity name from origin->entity instead of local->entity. Both point to the same entity, but the former conveys the meaning better. Signed-off-by: Laurent Pinchart Acked-by: Sakari Ailus Signed-off-by: Sakari Ailus Signed-off-by: Hans Verkuil

media: mc: Fix MUST_CONNECT handling for pads with no links

2025-08-25T13:40:44Z

Commit b3decc5ce7d7 ("media: mc: Expand MUST_CONNECT flag to always require an enabled link") expanded the meaning of the MUST_CONNECT flag to require an enabled link in all cases. To do so, the link exploration code was expanded to cover unconnected pads, in order to reject those that have the MUST_CONNECT flag set. The implementation was however incorrect, ignoring unconnected pads instead of ignoring connected pads. Fix it. Reported-by: Martin Kepplinger-Novaković Closes: https://lore.kernel.org/linux-media/20250205172957.182362-1-martink@posteo.de Reported-by: Maud Spierings Closes: https://lore.kernel.org/linux-media/20250818-imx8_isi-v1-1-e9cfe994c435@gocontroll.com Fixes: b3decc5ce7d7 ("media: mc: Expand MUST_CONNECT flag to always require an enabled link") Cc: stable@vger.kernel.org # 6.1 Signed-off-by: Laurent Pinchart Tested-by: Maud Spierings Tested-by: Martin Kepplinger-Novaković Signed-off-by: Sakari Ailus Signed-off-by: Hans Verkuil

media: mc: Rename pad as origin in __media_pipeline_start()

2024-11-07T08:05:58Z

Rename the pad field in __media_pipeline_start() to both better describe what it is and avoid masking it during the loop. Signed-off-by: Sakari Ailus Reviewed-by: Laurent Pinchart Signed-off-by: Hans Verkuil

media: mc: Fix graph walk in media_pipeline_start

2024-04-10T13:15:31Z

The graph walk tries to follow all links, even if they are not between pads. This causes a crash with, e.g. a MEDIA_LNK_FL_ANCILLARY_LINK link. Fix this by allowing the walk to proceed only for MEDIA_LNK_FL_DATA_LINK links. Signed-off-by: Tomi Valkeinen Cc: stable@vger.kernel.org # for 6.1 and later Fixes: ae219872834a ("media: mc: entity: Rewrite media_pipeline_start()") Signed-off-by: Sakari Ailus Signed-off-by: Hans Verkuil

media: mc: Expand MUST_CONNECT flag to always require an enabled link

2024-02-05T13:29:34Z

The MEDIA_PAD_FL_MUST_CONNECT flag indicates that the pad requires an enabled link to stream, but only if it has any link at all. This makes little sense, as if a pad is part of a pipeline, there are very few use cases for an active link to be mandatory only if links exist at all. A review of in-tree drivers confirms they all need an enabled link for pads marked with the MEDIA_PAD_FL_MUST_CONNECT flag. Expand the scope of the flag by rejecting pads that have no links at all. This requires modifying the pipeline build code to add those pads to the pipeline. Cc: stable@vger.kernel.org # 6.1 Signed-off-by: Laurent Pinchart Acked-by: Sakari Ailus Signed-off-by: Hans Verkuil

media: mc: Rename pad variable to clarify intent

2024-02-05T13:29:34Z

The pad local variable in the media_pipeline_explore_next_link() function is used to store the pad through which the entity has been reached. Rename it to origin to reflect that and make the code easier to read. This will be even more important in subsequent commits when expanding the function with additional logic. Cc: stable@vger.kernel.org # 6.1 Signed-off-by: Laurent Pinchart Acked-by: Sakari Ailus Signed-off-by: Hans Verkuil

media: mc: Add num_links flag to media_pad

2024-02-05T13:29:34Z

Maintain a counter of the links connected to a pad in the media_pad structure. This helps checking if a pad is connected to anything, which will be used in the pipeline building code. Cc: stable@vger.kernel.org # 6.1 Signed-off-by: Laurent Pinchart Acked-by: Sakari Ailus Signed-off-by: Hans Verkuil

media: mc: Fix flags handling when creating pad links

2024-02-05T13:29:34Z

The media_create_pad_link() function doesn't correctly clear reject link type flags, nor does it set the DATA_LINK flag. It only works because the MEDIA_LNK_FL_DATA_LINK flag's value is 0. Fix it by returning an error if any link type flag is set. This doesn't introduce any regression, as nobody calls the media_create_pad_link() function with link type flags (easily checked by grepping for the flag in the source code, there are very few hits). Set the MEDIA_LNK_FL_DATA_LINK explicitly, which is a no-op that the compiler will optimize out, but is still useful to make the code more explicit and easier to understand. Cc: stable@vger.kernel.org # 6.1 Signed-off-by: Laurent Pinchart Acked-by: Sakari Ailus Signed-off-by: Hans Verkuil

media: mc: Add local pad to pipeline regardless of the link state

2024-02-05T13:29:34Z

When building pipelines by following links, the media_pipeline_explore_next_link() function only traverses enabled links. The remote pad of a disabled link is not added to the pipeline, and neither is the local pad. While the former is correct as disabled links should not be followed, not adding the local pad breaks processing of the MEDIA_PAD_FL_MUST_CONNECT flag. The MEDIA_PAD_FL_MUST_CONNECT flag is checked in the __media_pipeline_start() function that iterates over all pads after populating the pipeline. If the pad is not present, the check gets skipped, rendering it useless. Fix this by adding the local pad of all links regardless of their state, only skipping the remote pad for disabled links. Cc: stable@vger.kernel.org # 6.1 Fixes: ae219872834a ("media: mc: entity: Rewrite media_pipeline_start()") Reported-by: Frieder Schrempf Closes: https://lore.kernel.org/linux-media/7658a15a-80c5-219f-2477-2a94ba6c6ba1@kontron.de Signed-off-by: Laurent Pinchart Acked-by: Sakari Ailus Signed-off-by: Hans Verkuil

media: mc: Check pad flag validity

2023-10-07T08:55:48Z

Check the validity of pad flags on entity init. Exactly one of the flags must be set. Signed-off-by: Sakari Ailus Reviewed-by: Laurent Pinchart Signed-off-by: Hans Verkuil