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authorLaurent Pinchart <laurent.pinchart@ideasonboard.com>2019-09-09 17:18:03 +0300
committerLaurent Pinchart <laurent.pinchart@ideasonboard.com>2019-09-13 20:13:26 +0300
commit04b20723d457e2e101f3c019046948bbe9c34980 (patch)
treefac1b002fa56c52d4d09f5065637cb4b71dafd48
parente832a00bab6153e4bc3044dc413cee24e5181498 (diff)
libcamera: device_enumerator_udev: Support entities sharing device nodes
Some media devices, such as V4L2 M2M devices, share the same device node for multiple entities. The udev enumerator used to support this, but commit 6e620349009d ("libcamera: device_enumerator: fix udev media graph loading dependency") broke this. To fix the problem, rework the media device to V4L2 devices matching code. A new MediaDeviceDeps internal struct stores unmet device number dependencies for a media device, and is stored in a list of pending media devices. To avoid linear lookups, the dependencies are cached in a reverse map of device number to media device dependencies. Fixes: 6e620349009d ("libcamera: device_enumerator: fix udev media graph loading dependency") Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Tested-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
-rw-r--r--src/libcamera/device_enumerator_udev.cpp100
-rw-r--r--src/libcamera/include/device_enumerator_udev.h25
2 files changed, 89 insertions, 36 deletions
diff --git a/src/libcamera/device_enumerator_udev.cpp b/src/libcamera/device_enumerator_udev.cpp
index c4077091..ddcd59ea 100644
--- a/src/libcamera/device_enumerator_udev.cpp
+++ b/src/libcamera/device_enumerator_udev.cpp
@@ -170,8 +170,8 @@ done:
int DeviceEnumeratorUdev::populateMediaDevice(const std::shared_ptr<MediaDevice> &media)
{
- unsigned int pendingNodes = 0;
- int ret;
+ std::set<dev_t> children;
+ DependencyMap deps;
/* Associate entities to device node paths. */
for (MediaEntity *entity : media->entities()) {
@@ -181,28 +181,50 @@ int DeviceEnumeratorUdev::populateMediaDevice(const std::shared_ptr<MediaDevice>
dev_t devnum = makedev(entity->deviceMajor(),
entity->deviceMinor());
- /* Take device from orphan list first, if it is in the list. */
- auto orphan = std::find(orphans_.begin(), orphans_.end(), devnum);
- if (orphan != orphans_.end()) {
- std::string deviceNode = lookupDeviceNode(devnum);
- if (deviceNode.empty())
- return -EINVAL;
-
- ret = entity->setDeviceNode(deviceNode);
- if (ret)
- return ret;
-
- orphans_.erase(orphan);
+ /*
+ * If the devnum isn't in the orphans list, add it to the unmet
+ * dependencies.
+ */
+ if (orphans_.find(devnum) == orphans_.end()) {
+ deps[devnum].push_back(entity);
continue;
}
- deps_[media].push_back(devnum);
- devnumToDevice_[devnum] = media;
- devnumToEntity_[devnum] = entity;
- pendingNodes++;
+ /*
+ * Otherwise take it from the orphans list. Don't remove the
+ * entry from the list yet as other entities in this media
+ * device may need the same device.
+ */
+ std::string deviceNode = lookupDeviceNode(devnum);
+ if (deviceNode.empty())
+ return -EINVAL;
+
+ int ret = entity->setDeviceNode(deviceNode);
+ if (ret)
+ return ret;
+
+ children.insert(devnum);
}
- return pendingNodes;
+ /* Remove all found children from the orphans list. */
+ for (auto it = orphans_.begin(), last = orphans_.end(); it != last;) {
+ if (children.find(*it) != children.end())
+ it = orphans_.erase(it);
+ else
+ ++it;
+ }
+
+ /*
+ * If the media device has unmet dependencies, add it to the pending
+ * list and update the devnum map accordingly.
+ */
+ if (!deps.empty()) {
+ pending_.emplace_back(media, deps);
+ for (const auto &dep : deps)
+ devMap_[dep.first] = &pending_.back();
+ }
+
+ return deps.size();
}
/**
@@ -247,28 +269,42 @@ std::string DeviceEnumeratorUdev::lookupDeviceNode(dev_t devnum)
*/
int DeviceEnumeratorUdev::addV4L2Device(dev_t devnum)
{
- MediaEntity *entity = devnumToEntity_[devnum];
- if (!entity) {
- orphans_.push_back(devnum);
+ /*
+ * If the devnum doesn't belong to any media device, add it to the
+ * orphans list.
+ */
+ auto it = devMap_.find(devnum);
+ if (it == devMap_.end()) {
+ orphans_.insert(devnum);
return 0;
}
+ /*
+ * Set the device node for all entities matching the devnum. Multiple
+ * entities can share the same device node, for instance for V4L2 M2M
+ * devices.
+ */
std::string deviceNode = lookupDeviceNode(devnum);
if (deviceNode.empty())
return -EINVAL;
- int ret = entity->setDeviceNode(deviceNode);
- if (ret)
- return ret;
+ MediaDeviceDeps *deps = it->second;
+ for (MediaEntity *entity : deps->deps_[devnum]) {
+ int ret = entity->setDeviceNode(deviceNode);
+ if (ret)
+ return ret;
+ }
- std::shared_ptr<MediaDevice> media = devnumToDevice_[devnum];
- deps_[media].remove(devnum);
- devnumToDevice_.erase(devnum);
- devnumToEntity_.erase(devnum);
+ /*
+ * Remove the devnum from the unmet dependencies for this media device.
+ * If no more dependency is unmet, add the media device to the
+ * enumerator.
+ */
+ deps->deps_.erase(devnum);
- if (deps_[media].empty()) {
- addDevice(media);
- deps_.erase(media);
+ if (deps->deps_.empty()) {
+ addDevice(deps->media_);
+ pending_.remove(*deps);
}
return 0;
diff --git a/src/libcamera/include/device_enumerator_udev.h b/src/libcamera/include/device_enumerator_udev.h
index fb7cac80..6d826862 100644
--- a/src/libcamera/include/device_enumerator_udev.h
+++ b/src/libcamera/include/device_enumerator_udev.h
@@ -10,6 +10,7 @@
#include <list>
#include <map>
#include <memory>
+#include <set>
#include <string>
#include <sys/types.h>
@@ -39,11 +40,27 @@ private:
struct udev_monitor *monitor_;
EventNotifier *notifier_;
- std::map<std::shared_ptr<MediaDevice>, std::list<dev_t>> deps_;
- std::map<dev_t, std::shared_ptr<MediaDevice>> devnumToDevice_;
- std::map<dev_t, MediaEntity *> devnumToEntity_;
+ using DependencyMap = std::map<dev_t, std::list<MediaEntity *>>;
- std::list<dev_t> orphans_;
+ struct MediaDeviceDeps {
+ MediaDeviceDeps(const std::shared_ptr<MediaDevice> &media,
+ const DependencyMap &deps)
+ : media_(media), deps_(deps)
+ {
+ }
+
+ bool operator==(const MediaDeviceDeps &other) const
+ {
+ return media_ == other.media_;
+ }
+
+ std::shared_ptr<MediaDevice> media_;
+ DependencyMap deps_;
+ };
+
+ std::set<dev_t> orphans_;
+ std::list<MediaDeviceDeps> pending_;
+ std::map<dev_t, MediaDeviceDeps *> devMap_;
int addUdevDevice(struct udev_device *dev);
int populateMediaDevice(const std::shared_ptr<MediaDevice> &media);