[libcamera-devel] [PATCH v3] libcamera: media_device: Fallback to legacy ioctls on older kernels
Laurent Pinchart
laurent.pinchart at ideasonboard.com
Sat Jan 26 00:09:42 CET 2019
Prior to kernel v4.19, the MEDIA_IOC_G_TOPOLOGY ioctl didn't expose
entity flags. Fallback to calling MEDIA_IOC_ENUM_ENTITIES for each
entity to retrieve the flags in that case.
Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
---
Changes since v1:
- Move MEDIA_V2_ENTITY_HAS_FLAGS() test to populateEntities()
- Rename fixupEntity() to fixupEntityFlag()
---
src/libcamera/include/media_device.h | 3 ++
src/libcamera/media_device.cpp | 41 ++++++++++++++++++++++++++--
2 files changed, 41 insertions(+), 3 deletions(-)
diff --git a/src/libcamera/include/media_device.h b/src/libcamera/include/media_device.h
index 27a2b46a4392..9f038093b2b2 100644
--- a/src/libcamera/include/media_device.h
+++ b/src/libcamera/include/media_device.h
@@ -56,6 +56,8 @@ private:
std::string driver_;
std::string deviceNode_;
std::string model_;
+ unsigned int version_;
+
int fd_;
bool valid_;
bool acquired_;
@@ -72,6 +74,7 @@ private:
bool populateEntities(const struct media_v2_topology &topology);
bool populatePads(const struct media_v2_topology &topology);
bool populateLinks(const struct media_v2_topology &topology);
+ void fixupEntityFlags(struct media_v2_entity *entity);
friend int MediaLink::setEnabled(bool enable);
int setupLink(const MediaLink *link, unsigned int flags);
diff --git a/src/libcamera/media_device.cpp b/src/libcamera/media_device.cpp
index be81bd8c4c23..a4995b996601 100644
--- a/src/libcamera/media_device.cpp
+++ b/src/libcamera/media_device.cpp
@@ -167,6 +167,7 @@ int MediaDevice::open()
driver_ = info.driver;
model_ = info.model;
+ version_ = info.media_version;
return 0;
}
@@ -553,20 +554,29 @@ bool MediaDevice::populateEntities(const struct media_v2_topology &topology)
(topology.ptr_entities);
for (unsigned int i = 0; i < topology.num_entities; ++i) {
+ struct media_v2_entity *ent = &mediaEntities[i];
+
+ /*
+ * The media_v2_entity structure was missing the flag field before
+ * v4.19.
+ */
+ if (!MEDIA_V2_ENTITY_HAS_FLAGS(version_))
+ fixupEntityFlags(ent);
+
/*
* Find the interface linked to this entity to get the device
* node major and minor numbers.
*/
struct media_v2_interface *iface =
- findInterface(topology, mediaEntities[i].id);
+ findInterface(topology, ent->id);
MediaEntity *entity;
if (iface)
- entity = new MediaEntity(this, &mediaEntities[i],
+ entity = new MediaEntity(this, ent,
iface->devnode.major,
iface->devnode.minor);
else
- entity = new MediaEntity(this, &mediaEntities[i]);
+ entity = new MediaEntity(this, ent);
if (!addObject(entity)) {
delete entity;
@@ -657,6 +667,31 @@ bool MediaDevice::populateLinks(const struct media_v2_topology &topology)
return true;
}
+/**
+ * \brief Fixup entity flags using legacy API
+ * \param[in] entity The entity
+ *
+ * This function is used as a fallback to query entity flags using the legacy
+ * MEDIA_IOC_ENUM_ENTITIES ioctl when running on a kernel version that doesn't
+ * provide them through the MEDIA_IOC_G_TOPOLOGY ioctl.
+ */
+void MediaDevice::fixupEntityFlags(struct media_v2_entity *entity)
+{
+ struct media_entity_desc desc = {};
+ desc.id = entity->id;
+
+ int ret = ioctl(fd_, MEDIA_IOC_ENUM_ENTITIES, &desc);
+ if (ret < 0) {
+ ret = -errno;
+ LOG(MediaDevice, Debug)
+ << "Failed to retrieve information for entity "
+ << entity->id << ": " << strerror(-ret);
+ return;
+ }
+
+ entity->flags = desc.flags;
+}
+
/**
* \brief Apply \a flags to a link between two pads
* \param link The link to apply flags to
--
Regards,
Laurent Pinchart
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