* [PATCH v2 1/5] media/v4l2-ctrls: volatiles should not generate CH_VALUE
@ 2015-03-20 13:30 Ricardo Ribalda Delgado
2015-03-20 13:30 ` [PATCH v2 4/5] media/v4l2-ctrls: Always execute EXECUTE_ON_WRITE ctrls Ricardo Ribalda Delgado
2015-04-21 17:44 ` [PATCH v2 1/5] media/v4l2-ctrls: volatiles should not generate CH_VALUE Laurent Pinchart
0 siblings, 2 replies; 4+ messages in thread
From: Ricardo Ribalda Delgado @ 2015-03-20 13:30 UTC (permalink / raw)
To: Ricardo Ribalda Delgado, Hans Verkuil, Mauro Carvalho Chehab,
Arun Kumar K, Sylwester Nawrocki, Antti Palosaari, linux-media,
linux-kernel, Laurent Pinchart, Sakari Ailus
Volatile controls should not generate CH_VALUE events.
Set has_changed to false to prevent this happening.
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
---
v2: By Sakari Ailus <sakari.ailus@linux.intel.com>
Fix CodeStyle (sorry :S)
drivers/media/v4l2-core/v4l2-ctrls.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index 45c5b47..2ebc33e 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -1609,6 +1609,15 @@ static int cluster_changed(struct v4l2_ctrl *master)
if (ctrl == NULL)
continue;
+ /*
+ * Set has_changed to false to avoid generating
+ * the event V4L2_EVENT_CTRL_CH_VALUE
+ */
+ if (ctrl->flags & V4L2_CTRL_FLAG_VOLATILE) {
+ ctrl->has_changed = false;
+ continue;
+ }
+
for (idx = 0; !ctrl_changed && idx < ctrl->elems; idx++)
ctrl_changed = !ctrl->type_ops->equal(ctrl, idx,
ctrl->p_cur, ctrl->p_new);
--
2.1.4
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH v2 4/5] media/v4l2-ctrls: Always execute EXECUTE_ON_WRITE ctrls
2015-03-20 13:30 [PATCH v2 1/5] media/v4l2-ctrls: volatiles should not generate CH_VALUE Ricardo Ribalda Delgado
@ 2015-03-20 13:30 ` Ricardo Ribalda Delgado
2015-04-21 17:44 ` [PATCH v2 1/5] media/v4l2-ctrls: volatiles should not generate CH_VALUE Laurent Pinchart
1 sibling, 0 replies; 4+ messages in thread
From: Ricardo Ribalda Delgado @ 2015-03-20 13:30 UTC (permalink / raw)
To: Ricardo Ribalda Delgado, Hans Verkuil, Mauro Carvalho Chehab,
Arun Kumar K, Sylwester Nawrocki, Antti Palosaari, linux-media,
linux-kernel, Laurent Pinchart, Sakari Ailus
Any control with V4L2_CTRL_FLAG_EXECUTE_ON_WRITE set should return
changed == true in cluster_changed.
This forces the value to be passed to the driver even if it has not
changed.
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
---
v2: By Sakari Ailus <sakari.ailus@linux.intel.com>
Fix CodeStyle (sorry :S)
drivers/media/v4l2-core/v4l2-ctrls.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index bacaed6..04d7407 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -1611,6 +1611,10 @@ static int cluster_changed(struct v4l2_ctrl *master)
if (ctrl == NULL)
continue;
+
+ if (ctrl->flags & V4L2_CTRL_FLAG_EXECUTE_ON_WRITE)
+ changed = true;
+
/*
* Set has_changed to false to avoid generating
* the event V4L2_EVENT_CTRL_CH_VALUE
--
2.1.4
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v2 1/5] media/v4l2-ctrls: volatiles should not generate CH_VALUE
2015-03-20 13:30 [PATCH v2 1/5] media/v4l2-ctrls: volatiles should not generate CH_VALUE Ricardo Ribalda Delgado
2015-03-20 13:30 ` [PATCH v2 4/5] media/v4l2-ctrls: Always execute EXECUTE_ON_WRITE ctrls Ricardo Ribalda Delgado
@ 2015-04-21 17:44 ` Laurent Pinchart
2015-04-21 21:32 ` Ricardo Ribalda Delgado
1 sibling, 1 reply; 4+ messages in thread
From: Laurent Pinchart @ 2015-04-21 17:44 UTC (permalink / raw)
To: Ricardo Ribalda Delgado
Cc: Hans Verkuil, Mauro Carvalho Chehab, Arun Kumar K,
Sylwester Nawrocki, Antti Palosaari, linux-media, linux-kernel,
Sakari Ailus
Hi Ricardo,
Thank you for the patch, and sorry for the late review (so late that the patch
has already been merged).
On Friday 20 March 2015 14:30:46 Ricardo Ribalda Delgado wrote:
> Volatile controls should not generate CH_VALUE events.
What's the rationale for that ? I would actually expect the value change
events to be more useful for volatile controls than non-volatile controls.
Volatile controls can have their value changed by the hardware without
software intervention, and it makes sense to me to report that to userspace.
> Set has_changed to false to prevent this happening.
>
> Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
> ---
> v2: By Sakari Ailus <sakari.ailus@linux.intel.com>
>
> Fix CodeStyle (sorry :S)
> drivers/media/v4l2-core/v4l2-ctrls.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c
> b/drivers/media/v4l2-core/v4l2-ctrls.c index 45c5b47..2ebc33e 100644
> --- a/drivers/media/v4l2-core/v4l2-ctrls.c
> +++ b/drivers/media/v4l2-core/v4l2-ctrls.c
> @@ -1609,6 +1609,15 @@ static int cluster_changed(struct v4l2_ctrl *master)
>
> if (ctrl == NULL)
> continue;
> + /*
> + * Set has_changed to false to avoid generating
> + * the event V4L2_EVENT_CTRL_CH_VALUE
> + */
> + if (ctrl->flags & V4L2_CTRL_FLAG_VOLATILE) {
> + ctrl->has_changed = false;
> + continue;
> + }
> +
> for (idx = 0; !ctrl_changed && idx < ctrl->elems; idx++)
> ctrl_changed = !ctrl->type_ops->equal(ctrl, idx,
> ctrl->p_cur, ctrl->p_new);
--
Regards,
Laurent Pinchart
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2 1/5] media/v4l2-ctrls: volatiles should not generate CH_VALUE
2015-04-21 17:44 ` [PATCH v2 1/5] media/v4l2-ctrls: volatiles should not generate CH_VALUE Laurent Pinchart
@ 2015-04-21 21:32 ` Ricardo Ribalda Delgado
0 siblings, 0 replies; 4+ messages in thread
From: Ricardo Ribalda Delgado @ 2015-04-21 21:32 UTC (permalink / raw)
To: Laurent Pinchart
Cc: Hans Verkuil, Mauro Carvalho Chehab, Arun Kumar K,
Sylwester Nawrocki, Antti Palosaari, linux-media, LKML,
Sakari Ailus
Hello Laurent
On Tue, Apr 21, 2015 at 7:44 PM, Laurent Pinchart
<laurent.pinchart@ideasonboard.com> wrote:
> Hi Ricardo,
>
> Thank you for the patch, and sorry for the late review (so late that the patch
> has already been merged).
No worries.
>
> On Friday 20 March 2015 14:30:46 Ricardo Ribalda Delgado wrote:
>> Volatile controls should not generate CH_VALUE events.
>
> What's the rationale for that ? I would actually expect the value change
> events to be more useful for volatile controls than non-volatile controls.
> Volatile controls can have their value changed by the hardware without
> software intervention, and it makes sense to me to report that to userspace.
Imagine a temperature register on the sensor. It is changing
constantly, resolution 10 milidegrees:
Do you want to get an event for every change? Who will poll the
temperature? The driver? The hardware will irq the driver....?
So I guess the less wrong solution is not throwing the ch_value event.
This is just my two cents, probably Hans has a much better global view :)
Regards.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2015-04-21 21:32 UTC | newest]
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2015-03-20 13:30 ` [PATCH v2 4/5] media/v4l2-ctrls: Always execute EXECUTE_ON_WRITE ctrls Ricardo Ribalda Delgado
2015-04-21 17:44 ` [PATCH v2 1/5] media/v4l2-ctrls: volatiles should not generate CH_VALUE Laurent Pinchart
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