| Message ID | 20190715055935.21233-2-jacopo@jmondi.org |
|---|---|
| State | Superseded |
| Delegated to: | Jacopo Mondi |
| Headers | show |
| Series |
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| Related | show |
Hi Jacopo, Thank you for the patch. On Mon, Jul 15, 2019 at 07:59:33AM +0200, Jacopo Mondi wrote: > With the current IPU3 kernel driver implementation, if links are enabled on > an ImgU pipe buffers should be queued on its output devices in order not to > block the other pipe. > > Currently all links on the ImgU device are disabled at match() time, > implying that once an ImgU pipe gets linked, it should be used until the > whole pipeline handler is not re-matched and links disabled again. This is a > severe limitation for applications that wants to switch between cameras > using different pipes without going through a full library tear-down and > re-initialization. > > Move the link disabling at configure() time, so that a camera > configuration operation always unlock the usage of the assigned pipe, > regardless of the status of the one previously in use. > > Unfortunately this requires a camera start/stop sequence to always go > through a configure step, a requirement that is not enforced by the > Camera state machine. How about disabling links in both match() and stop() then ? > Signed-off-by: Jacopo Mondi <jacopo@jmondi.org> > --- > src/libcamera/pipeline/ipu3/ipu3.cpp | 55 +++++++++++++++------------- > 1 file changed, 29 insertions(+), 26 deletions(-) > > diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp > index 22987dbf1460..5204487684c2 100644 > --- a/src/libcamera/pipeline/ipu3/ipu3.cpp > +++ b/src/libcamera/pipeline/ipu3/ipu3.cpp > @@ -496,6 +496,35 @@ int PipelineHandlerIPU3::configure(Camera *camera, CameraConfiguration *c) > ImgUDevice *imgu = data->imgu_; > int ret; > > + /* > + * FIXME: enabled links in one ImgU pipe interfere with capture > + * operations on the other one. This can be easily triggered by > + * capturing from one camera and then trying to capture from the other > + * one right after, without disabling media links on the first pipe. > + * > + * The tricky part here is where to disable links on the ImgU instance > + * which is currently not in use: > + * 1) Link enable/disable cannot be done at start()/stop() time as video > + * devices needs to be linked first before format can be configured on > + * them. > + * 2) As link enable has to be done at the least in configure(), > + * before configuring formats, the only place where to disable links > + * would be 'stop()', but the Camera class state machine allows > + * start()<->stop() sequences without any configure() in between. > + * > + * As of now, disable all links in the ImgU media graph before > + * configuring the device, to allow alternate usage of two pipes. > + * > + * As a consequence, a Camera using an ImgU shall be configured before > + * any start()/stop() sequence. An application that wants to > + * pre-configure all the camera and then start/stop them alternatively > + * without going through any re-configuration (a sequence that is > + * allowed by the Camera state machine) would now fail on the IPU3. > + */ > + ret = imguMediaDev_->disableLinks(); > + if (ret) > + return ret; > + > /* > * \todo: Enable links selectively based on the requested streams. > * As of now, enable all links unconditionally. > @@ -778,32 +807,6 @@ bool PipelineHandlerIPU3::match(DeviceEnumerator *enumerator) > if (cio2MediaDev_->disableLinks()) > return false; > > - /* > - * FIXME: enabled links in one ImgU instance interfere with capture > - * operations on the other one. This can be easily triggered by > - * capturing from one camera and then trying to capture from the other > - * one right after, without disabling media links in the media graph > - * first. > - * > - * The tricky part here is where to disable links on the ImgU instance > - * which is currently not in use: > - * 1) Link enable/disable cannot be done at start/stop time as video > - * devices needs to be linked first before format can be configured on > - * them. > - * 2) As link enable has to be done at the least in configure(), > - * before configuring formats, the only place where to disable links > - * would be 'stop()', but the Camera class state machine allows > - * start()<->stop() sequences without any configure() in between. > - * > - * As of now, disable all links in the media graph at 'match()' time, > - * to allow testing different cameras in different test applications > - * runs. A test application that would use two distinct cameras without > - * going through a library teardown->match() sequence would fail > - * at the moment. > - */ > - ret = imguMediaDev_->disableLinks(); > - if (ret) > - return ret; > > ret = registerCameras(); >
Hi Laurent, On Mon, Jul 15, 2019 at 09:41:35AM +0300, Laurent Pinchart wrote: > Hi Jacopo, > > Thank you for the patch. > > On Mon, Jul 15, 2019 at 07:59:33AM +0200, Jacopo Mondi wrote: > > With the current IPU3 kernel driver implementation, if links are enabled on > > an ImgU pipe buffers should be queued on its output devices in order not to > > block the other pipe. > > > > Currently all links on the ImgU device are disabled at match() time, > > implying that once an ImgU pipe gets linked, it should be used until the > > whole pipeline handler is not re-matched and links disabled again. This is a > > severe limitation for applications that wants to switch between cameras > > using different pipes without going through a full library tear-down and > > re-initialization. > > > > Move the link disabling at configure() time, so that a camera > > configuration operation always unlock the usage of the assigned pipe, > > regardless of the status of the one previously in use. > > > > Unfortunately this requires a camera start/stop sequence to always go > > through a configure step, a requirement that is not enforced by the > > Camera state machine. > > How about disabling links in both match() and stop() then ? Fine with match() as starting with a clean media device is desirable (I'll move the comment here anyway). If we move this at stop() time though, a start->stop->start sequence would always fail, so I would avoid that. Thanks j > > > Signed-off-by: Jacopo Mondi <jacopo@jmondi.org> > > --- > > src/libcamera/pipeline/ipu3/ipu3.cpp | 55 +++++++++++++++------------- > > 1 file changed, 29 insertions(+), 26 deletions(-) > > > > diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp > > index 22987dbf1460..5204487684c2 100644 > > --- a/src/libcamera/pipeline/ipu3/ipu3.cpp > > +++ b/src/libcamera/pipeline/ipu3/ipu3.cpp > > @@ -496,6 +496,35 @@ int PipelineHandlerIPU3::configure(Camera *camera, CameraConfiguration *c) > > ImgUDevice *imgu = data->imgu_; > > int ret; > > > > + /* > > + * FIXME: enabled links in one ImgU pipe interfere with capture > > + * operations on the other one. This can be easily triggered by > > + * capturing from one camera and then trying to capture from the other > > + * one right after, without disabling media links on the first pipe. > > + * > > + * The tricky part here is where to disable links on the ImgU instance > > + * which is currently not in use: > > + * 1) Link enable/disable cannot be done at start()/stop() time as video > > + * devices needs to be linked first before format can be configured on > > + * them. > > + * 2) As link enable has to be done at the least in configure(), > > + * before configuring formats, the only place where to disable links > > + * would be 'stop()', but the Camera class state machine allows > > + * start()<->stop() sequences without any configure() in between. > > + * > > + * As of now, disable all links in the ImgU media graph before > > + * configuring the device, to allow alternate usage of two pipes. > > + * > > + * As a consequence, a Camera using an ImgU shall be configured before > > + * any start()/stop() sequence. An application that wants to > > + * pre-configure all the camera and then start/stop them alternatively > > + * without going through any re-configuration (a sequence that is > > + * allowed by the Camera state machine) would now fail on the IPU3. > > + */ > > + ret = imguMediaDev_->disableLinks(); > > + if (ret) > > + return ret; > > + > > /* > > * \todo: Enable links selectively based on the requested streams. > > * As of now, enable all links unconditionally. > > @@ -778,32 +807,6 @@ bool PipelineHandlerIPU3::match(DeviceEnumerator *enumerator) > > if (cio2MediaDev_->disableLinks()) > > return false; > > > > - /* > > - * FIXME: enabled links in one ImgU instance interfere with capture > > - * operations on the other one. This can be easily triggered by > > - * capturing from one camera and then trying to capture from the other > > - * one right after, without disabling media links in the media graph > > - * first. > > - * > > - * The tricky part here is where to disable links on the ImgU instance > > - * which is currently not in use: > > - * 1) Link enable/disable cannot be done at start/stop time as video > > - * devices needs to be linked first before format can be configured on > > - * them. > > - * 2) As link enable has to be done at the least in configure(), > > - * before configuring formats, the only place where to disable links > > - * would be 'stop()', but the Camera class state machine allows > > - * start()<->stop() sequences without any configure() in between. > > - * > > - * As of now, disable all links in the media graph at 'match()' time, > > - * to allow testing different cameras in different test applications > > - * runs. A test application that would use two distinct cameras without > > - * going through a library teardown->match() sequence would fail > > - * at the moment. > > - */ > > - ret = imguMediaDev_->disableLinks(); > > - if (ret) > > - return ret; > > > > ret = registerCameras(); > > > > -- > Regards, > > Laurent Pinchart
diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp index 22987dbf1460..5204487684c2 100644 --- a/src/libcamera/pipeline/ipu3/ipu3.cpp +++ b/src/libcamera/pipeline/ipu3/ipu3.cpp @@ -496,6 +496,35 @@ int PipelineHandlerIPU3::configure(Camera *camera, CameraConfiguration *c) ImgUDevice *imgu = data->imgu_; int ret; + /* + * FIXME: enabled links in one ImgU pipe interfere with capture + * operations on the other one. This can be easily triggered by + * capturing from one camera and then trying to capture from the other + * one right after, without disabling media links on the first pipe. + * + * The tricky part here is where to disable links on the ImgU instance + * which is currently not in use: + * 1) Link enable/disable cannot be done at start()/stop() time as video + * devices needs to be linked first before format can be configured on + * them. + * 2) As link enable has to be done at the least in configure(), + * before configuring formats, the only place where to disable links + * would be 'stop()', but the Camera class state machine allows + * start()<->stop() sequences without any configure() in between. + * + * As of now, disable all links in the ImgU media graph before + * configuring the device, to allow alternate usage of two pipes. + * + * As a consequence, a Camera using an ImgU shall be configured before + * any start()/stop() sequence. An application that wants to + * pre-configure all the camera and then start/stop them alternatively + * without going through any re-configuration (a sequence that is + * allowed by the Camera state machine) would now fail on the IPU3. + */ + ret = imguMediaDev_->disableLinks(); + if (ret) + return ret; + /* * \todo: Enable links selectively based on the requested streams. * As of now, enable all links unconditionally. @@ -778,32 +807,6 @@ bool PipelineHandlerIPU3::match(DeviceEnumerator *enumerator) if (cio2MediaDev_->disableLinks()) return false; - /* - * FIXME: enabled links in one ImgU instance interfere with capture - * operations on the other one. This can be easily triggered by - * capturing from one camera and then trying to capture from the other - * one right after, without disabling media links in the media graph - * first. - * - * The tricky part here is where to disable links on the ImgU instance - * which is currently not in use: - * 1) Link enable/disable cannot be done at start/stop time as video - * devices needs to be linked first before format can be configured on - * them. - * 2) As link enable has to be done at the least in configure(), - * before configuring formats, the only place where to disable links - * would be 'stop()', but the Camera class state machine allows - * start()<->stop() sequences without any configure() in between. - * - * As of now, disable all links in the media graph at 'match()' time, - * to allow testing different cameras in different test applications - * runs. A test application that would use two distinct cameras without - * going through a library teardown->match() sequence would fail - * at the moment. - */ - ret = imguMediaDev_->disableLinks(); - if (ret) - return ret; ret = registerCameras();
With the current IPU3 kernel driver implementation, if links are enabled on an ImgU pipe buffers should be queued on its output devices in order not to block the other pipe. Currently all links on the ImgU device are disabled at match() time, implying that once an ImgU pipe gets linked, it should be used until the whole pipeline handler is not re-matched and links disabled again. This is a severe limitation for applications that wants to switch between cameras using different pipes without going through a full library tear-down and re-initialization. Move the link disabling at configure() time, so that a camera configuration operation always unlock the usage of the assigned pipe, regardless of the status of the one previously in use. Unfortunately this requires a camera start/stop sequence to always go through a configure step, a requirement that is not enforced by the Camera state machine. Signed-off-by: Jacopo Mondi <jacopo@jmondi.org> --- src/libcamera/pipeline/ipu3/ipu3.cpp | 55 +++++++++++++++------------- 1 file changed, 29 insertions(+), 26 deletions(-)