On 17/09/2024 17:57, Laurent Pinchart wrote:
On Tue, Sep 17, 2024 at 05:16:25PM +0300, Tomi Valkeinen wrote:
On 17/09/2024 16:00, Laurent Pinchart wrote:
On Tue, Sep 17, 2024 at 03:43:45PM +0300, Sakari Ailus wrote:
Document the expected {enable,disable}_streams callback behaviour for
drivers that are stream-unaware i.e. don't specify the
V4L2_SUBDEV_CAP_STREAMS sub-device capability flat. In this specific case,
the mask argument can be ignored.
Wouldn't it be better to use BIT(0) in that case to simplifiy
interoperability with stream-aware devices ?
The caller has to set BIT(0), but I think here the documentation is
about the callee.
If the driver is not stream aware and implements the callbacks, it will
get BIT(0) as the mask parameter (do we enforce this?), but as there's
nothing it can do with the parameter it "does not need to be concerned
with the mask argument".
Right. I had misunderstood the patch.
Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
---
include/media/v4l2-subdev.h | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
index 3cc6b4a5935f..67a6e6ec58b8 100644
--- a/include/media/v4l2-subdev.h
+++ b/include/media/v4l2-subdev.h
@@ -834,11 +834,19 @@ struct v4l2_subdev_state {
* v4l2_subdev_init_finalize() at initialization time). Do not call
* directly, use v4l2_subdev_enable_streams() instead.
*
+ * Drivers that support only a single stream without setting the
+ * V4L2_SUBDEV_CAP_STREAMS sub-device capatility flag do not need to
s/capatility/capability/
Same below.
+ * be concerned with the mask argument.
How about "can ignore the mask argument" instead ? I interpreted as "not
need to be concerned with" from the point of view of the caller.
Or maybe, to be transparent, "can ignore the mask argument as it is
always 1".
Tomi
