| Message ID | 20240416193319.778192-12-sakari.ailus@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Generic line based metadata support, internal pads | expand |
Hi Sakari, Thank you for the patch. On Tue, Apr 16, 2024 at 10:32:44PM +0300, Sakari Ailus wrote: > Document S_ROUTING behaviour for different devices. > > Generally in devices that produce streams the streams are static and some > can be enabled and disabled, whereas in devices that just transport them > or write them to memory, more configurability is allowed. Document this. > > Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> > Reviewed-by: Julien Massot <julien.massot@collabora.com> > --- > .../userspace-api/media/v4l/dev-subdev.rst | 24 +++++++++++++++++++ > 1 file changed, 24 insertions(+) > > diff --git a/Documentation/userspace-api/media/v4l/dev-subdev.rst b/Documentation/userspace-api/media/v4l/dev-subdev.rst > index d30dcb9e2537..de8dfd4f11a5 100644 > --- a/Documentation/userspace-api/media/v4l/dev-subdev.rst > +++ b/Documentation/userspace-api/media/v4l/dev-subdev.rst > @@ -593,6 +593,30 @@ Any configurations of a stream within a pad, such as format or selections, > are independent of similar configurations on other streams. This is > subject to change in the future. > > +Device types and routing setup > +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > + > +Different kinds of sub-devices have differing behaviour for route activation, > +depending on the hardware. In all cases, however, only routes that have the > +``V4L2_SUBDEV_STREAM_FL_ACTIVE`` flag set are active. > + > +Devices generating the streams may allow enabling and disabling some of the > +routes or the configuration is fixed. If the routes can be disabled, not "... some of the routes, or have a fixed routing configuration." > +declaring the routes (or declaring them without > +``VIDIOC_SUBDEV_STREAM_FL_ACTIVE`` flag set) in ``VIDIOC_SUBDEV_S_ROUTING`` will > +disable the routes while the sub-device driver retains the streams and their > +format and selection configuration. I still find the "retains their format and selection configuration" quite unclear :-S > The ``VIDIOC_SUBDEV_S_ROUTING`` will still s/will still/ioctl will still/ > +return such routes back to the user in the routes array, with the > +``V4L2_SUBDEV_STREAM_FL_ACTIVE`` flag unset. > + > +Devices transporting the streams almost always have more configurability with > +respect to routing. Typically any route between the sub-device's sink and source > +pads is possible, and multiple routes (usually up to certain limited number) may > +be active simultaneously. For such devices, no routes are created by the driver > +and user-created routes are fully replaced when ``VIDIOC_SUBDEV_S_ROUTING`` is > +called on the sub-device. Such newly created routes have the device's default > +configuration for format and selection rectangles. > + > Configuring streams > ^^^^^^^^^^^^^^^^^^^ >
Hi Laurent, On Fri, Apr 19, 2024 at 08:17:20PM +0300, Laurent Pinchart wrote: > Hi Sakari, > > Thank you for the patch. > > On Tue, Apr 16, 2024 at 10:32:44PM +0300, Sakari Ailus wrote: > > Document S_ROUTING behaviour for different devices. > > > > Generally in devices that produce streams the streams are static and some > > can be enabled and disabled, whereas in devices that just transport them > > or write them to memory, more configurability is allowed. Document this. > > > > Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> > > Reviewed-by: Julien Massot <julien.massot@collabora.com> > > --- > > .../userspace-api/media/v4l/dev-subdev.rst | 24 +++++++++++++++++++ > > 1 file changed, 24 insertions(+) > > > > diff --git a/Documentation/userspace-api/media/v4l/dev-subdev.rst b/Documentation/userspace-api/media/v4l/dev-subdev.rst > > index d30dcb9e2537..de8dfd4f11a5 100644 > > --- a/Documentation/userspace-api/media/v4l/dev-subdev.rst > > +++ b/Documentation/userspace-api/media/v4l/dev-subdev.rst > > @@ -593,6 +593,30 @@ Any configurations of a stream within a pad, such as format or selections, > > are independent of similar configurations on other streams. This is > > subject to change in the future. > > > > +Device types and routing setup > > +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > + > > +Different kinds of sub-devices have differing behaviour for route activation, > > +depending on the hardware. In all cases, however, only routes that have the > > +``V4L2_SUBDEV_STREAM_FL_ACTIVE`` flag set are active. > > + > > +Devices generating the streams may allow enabling and disabling some of the > > +routes or the configuration is fixed. If the routes can be disabled, not > > "... some of the routes, or have a fixed routing configuration." Seems fine. > > > +declaring the routes (or declaring them without > > +``VIDIOC_SUBDEV_STREAM_FL_ACTIVE`` flag set) in ``VIDIOC_SUBDEV_S_ROUTING`` will > > +disable the routes while the sub-device driver retains the streams and their > > +format and selection configuration. > > I still find the "retains their format and selection configuration" > quite unclear :-S Alternatively we could say that the routes are simply not active, without referring to explicitly to formats and selections. I.e.: If the routes can be disabled, not declaring the routes (or declaring them without ``VIDIOC_SUBDEV_STREAM_FL_ACTIVE`` flag set) in ``VIDIOC_SUBDEV_S_ROUTING`` will disable the routes. > > > The ``VIDIOC_SUBDEV_S_ROUTING`` will still > > s/will still/ioctl will still/ Both seem to exist, more common is without "ioctl": $ git grep '[`<]VIDIOC_SUBDEV' -- Documentation/userspace-api/media/|wc -l 84 $ git grep -i "VIDIOC_SUBDEV.*ioctl" -- Documentation/userspace-api/media/|wc -l 34 > > > +return such routes back to the user in the routes array, with the > > +``V4L2_SUBDEV_STREAM_FL_ACTIVE`` flag unset. > > + > > +Devices transporting the streams almost always have more configurability with > > +respect to routing. Typically any route between the sub-device's sink and source > > +pads is possible, and multiple routes (usually up to certain limited number) may > > +be active simultaneously. For such devices, no routes are created by the driver > > +and user-created routes are fully replaced when ``VIDIOC_SUBDEV_S_ROUTING`` is > > +called on the sub-device. Such newly created routes have the device's default > > +configuration for format and selection rectangles. > > + > > Configuring streams > > ^^^^^^^^^^^^^^^^^^^ > > >
Hi Sakari, On Tue, Apr 23, 2024 at 10:08:05AM +0000, Sakari Ailus wrote: > On Fri, Apr 19, 2024 at 08:17:20PM +0300, Laurent Pinchart wrote: > > On Tue, Apr 16, 2024 at 10:32:44PM +0300, Sakari Ailus wrote: > > > Document S_ROUTING behaviour for different devices. > > > > > > Generally in devices that produce streams the streams are static and some > > > can be enabled and disabled, whereas in devices that just transport them > > > or write them to memory, more configurability is allowed. Document this. > > > > > > Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> > > > Reviewed-by: Julien Massot <julien.massot@collabora.com> > > > --- > > > .../userspace-api/media/v4l/dev-subdev.rst | 24 +++++++++++++++++++ > > > 1 file changed, 24 insertions(+) > > > > > > diff --git a/Documentation/userspace-api/media/v4l/dev-subdev.rst b/Documentation/userspace-api/media/v4l/dev-subdev.rst > > > index d30dcb9e2537..de8dfd4f11a5 100644 > > > --- a/Documentation/userspace-api/media/v4l/dev-subdev.rst > > > +++ b/Documentation/userspace-api/media/v4l/dev-subdev.rst > > > @@ -593,6 +593,30 @@ Any configurations of a stream within a pad, such as format or selections, > > > are independent of similar configurations on other streams. This is > > > subject to change in the future. > > > > > > +Device types and routing setup > > > +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > > + > > > +Different kinds of sub-devices have differing behaviour for route activation, > > > +depending on the hardware. In all cases, however, only routes that have the > > > +``V4L2_SUBDEV_STREAM_FL_ACTIVE`` flag set are active. > > > + > > > +Devices generating the streams may allow enabling and disabling some of the > > > +routes or the configuration is fixed. If the routes can be disabled, not > > > > "... some of the routes, or have a fixed routing configuration." > > Seems fine. > > > > +declaring the routes (or declaring them without > > > +``VIDIOC_SUBDEV_STREAM_FL_ACTIVE`` flag set) in ``VIDIOC_SUBDEV_S_ROUTING`` will > > > +disable the routes while the sub-device driver retains the streams and their > > > +format and selection configuration. > > > > I still find the "retains their format and selection configuration" > > quite unclear :-S > > Alternatively we could say that the routes are simply not active, without > referring to explicitly to formats and selections. I.e.: > > If the routes can be disabled, not declaring the routes (or declaring them > without ``VIDIOC_SUBDEV_STREAM_FL_ACTIVE`` flag set) in > ``VIDIOC_SUBDEV_S_ROUTING`` will disable the routes. I'm fine with that. > > > The ``VIDIOC_SUBDEV_S_ROUTING`` will still > > > > s/will still/ioctl will still/ > > Both seem to exist, more common is without "ioctl": > > $ git grep '[`<]VIDIOC_SUBDEV' -- Documentation/userspace-api/media/|wc -l > 84 > $ git grep -i "VIDIOC_SUBDEV.*ioctl" -- Documentation/userspace-api/media/|wc -l > 34 You'll often find "ioctl" at the beginning of the next line :-) If you would like to avoid it, you should drop "The" at the beginning of the sentence. > > > +return such routes back to the user in the routes array, with the > > > +``V4L2_SUBDEV_STREAM_FL_ACTIVE`` flag unset. > > > + > > > +Devices transporting the streams almost always have more configurability with > > > +respect to routing. Typically any route between the sub-device's sink and source > > > +pads is possible, and multiple routes (usually up to certain limited number) may > > > +be active simultaneously. For such devices, no routes are created by the driver > > > +and user-created routes are fully replaced when ``VIDIOC_SUBDEV_S_ROUTING`` is > > > +called on the sub-device. Such newly created routes have the device's default > > > +configuration for format and selection rectangles. > > > + > > > Configuring streams > > > ^^^^^^^^^^^^^^^^^^^ > > >
Hi Laurent, On Tue, Apr 23, 2024 at 03:59:44PM +0300, Laurent Pinchart wrote: > Hi Sakari, > > On Tue, Apr 23, 2024 at 10:08:05AM +0000, Sakari Ailus wrote: > > On Fri, Apr 19, 2024 at 08:17:20PM +0300, Laurent Pinchart wrote: > > > On Tue, Apr 16, 2024 at 10:32:44PM +0300, Sakari Ailus wrote: > > > > Document S_ROUTING behaviour for different devices. > > > > > > > > Generally in devices that produce streams the streams are static and some > > > > can be enabled and disabled, whereas in devices that just transport them > > > > or write them to memory, more configurability is allowed. Document this. > > > > > > > > Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> > > > > Reviewed-by: Julien Massot <julien.massot@collabora.com> > > > > --- > > > > .../userspace-api/media/v4l/dev-subdev.rst | 24 +++++++++++++++++++ > > > > 1 file changed, 24 insertions(+) > > > > > > > > diff --git a/Documentation/userspace-api/media/v4l/dev-subdev.rst b/Documentation/userspace-api/media/v4l/dev-subdev.rst > > > > index d30dcb9e2537..de8dfd4f11a5 100644 > > > > --- a/Documentation/userspace-api/media/v4l/dev-subdev.rst > > > > +++ b/Documentation/userspace-api/media/v4l/dev-subdev.rst > > > > @@ -593,6 +593,30 @@ Any configurations of a stream within a pad, such as format or selections, > > > > are independent of similar configurations on other streams. This is > > > > subject to change in the future. > > > > > > > > +Device types and routing setup > > > > +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > > > + > > > > +Different kinds of sub-devices have differing behaviour for route activation, > > > > +depending on the hardware. In all cases, however, only routes that have the > > > > +``V4L2_SUBDEV_STREAM_FL_ACTIVE`` flag set are active. > > > > + > > > > +Devices generating the streams may allow enabling and disabling some of the > > > > +routes or the configuration is fixed. If the routes can be disabled, not > > > > > > "... some of the routes, or have a fixed routing configuration." > > > > Seems fine. > > > > > > +declaring the routes (or declaring them without > > > > +``VIDIOC_SUBDEV_STREAM_FL_ACTIVE`` flag set) in ``VIDIOC_SUBDEV_S_ROUTING`` will > > > > +disable the routes while the sub-device driver retains the streams and their > > > > +format and selection configuration. > > > > > > I still find the "retains their format and selection configuration" > > > quite unclear :-S > > > > Alternatively we could say that the routes are simply not active, without > > referring to explicitly to formats and selections. I.e.: > > > > If the routes can be disabled, not declaring the routes (or declaring them > > without ``VIDIOC_SUBDEV_STREAM_FL_ACTIVE`` flag set) in > > ``VIDIOC_SUBDEV_S_ROUTING`` will disable the routes. > > I'm fine with that. > > > > > The ``VIDIOC_SUBDEV_S_ROUTING`` will still > > > > > > s/will still/ioctl will still/ > > > > Both seem to exist, more common is without "ioctl": > > > > $ git grep '[`<]VIDIOC_SUBDEV' -- Documentation/userspace-api/media/|wc -l > > 84 > > $ git grep -i "VIDIOC_SUBDEV.*ioctl" -- Documentation/userspace-api/media/|wc -l > > 34 > > You'll often find "ioctl" at the beginning of the next line :-) If you > would like to avoid it, you should drop "The" at the beginning of the > sentence. Sounds good. > > > > > +return such routes back to the user in the routes array, with the > > > > +``V4L2_SUBDEV_STREAM_FL_ACTIVE`` flag unset. > > > > + > > > > +Devices transporting the streams almost always have more configurability with > > > > +respect to routing. Typically any route between the sub-device's sink and source > > > > +pads is possible, and multiple routes (usually up to certain limited number) may > > > > +be active simultaneously. For such devices, no routes are created by the driver > > > > +and user-created routes are fully replaced when ``VIDIOC_SUBDEV_S_ROUTING`` is > > > > +called on the sub-device. Such newly created routes have the device's default > > > > +configuration for format and selection rectangles. > > > > + > > > > Configuring streams > > > > ^^^^^^^^^^^^^^^^^^^ > > > > >
diff --git a/Documentation/userspace-api/media/v4l/dev-subdev.rst b/Documentation/userspace-api/media/v4l/dev-subdev.rst index d30dcb9e2537..de8dfd4f11a5 100644 --- a/Documentation/userspace-api/media/v4l/dev-subdev.rst +++ b/Documentation/userspace-api/media/v4l/dev-subdev.rst @@ -593,6 +593,30 @@ Any configurations of a stream within a pad, such as format or selections, are independent of similar configurations on other streams. This is subject to change in the future. +Device types and routing setup +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Different kinds of sub-devices have differing behaviour for route activation, +depending on the hardware. In all cases, however, only routes that have the +``V4L2_SUBDEV_STREAM_FL_ACTIVE`` flag set are active. + +Devices generating the streams may allow enabling and disabling some of the +routes or the configuration is fixed. If the routes can be disabled, not +declaring the routes (or declaring them without +``VIDIOC_SUBDEV_STREAM_FL_ACTIVE`` flag set) in ``VIDIOC_SUBDEV_S_ROUTING`` will +disable the routes while the sub-device driver retains the streams and their +format and selection configuration. The ``VIDIOC_SUBDEV_S_ROUTING`` will still +return such routes back to the user in the routes array, with the +``V4L2_SUBDEV_STREAM_FL_ACTIVE`` flag unset. + +Devices transporting the streams almost always have more configurability with +respect to routing. Typically any route between the sub-device's sink and source +pads is possible, and multiple routes (usually up to certain limited number) may +be active simultaneously. For such devices, no routes are created by the driver +and user-created routes are fully replaced when ``VIDIOC_SUBDEV_S_ROUTING`` is +called on the sub-device. Such newly created routes have the device's default +configuration for format and selection rectangles. + Configuring streams ^^^^^^^^^^^^^^^^^^^