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| Started by | Pavel Machek <pavel@ucw.cz> |
|---|---|
| First post | 2017-02-14 14:50 +0100 |
| Last post | 2017-02-14 23:30 +0100 |
| Articles | 5 — 3 participants |
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[RFC 07/13] v4l2: device_register_subdev_nodes: allow calling multiple times Pavel Machek <pavel@ucw.cz> - 2017-02-14 14:50 +0100
Re: [RFC 07/13] v4l2: device_register_subdev_nodes: allow calling multiple times Sakari Ailus <sakari.ailus@iki.fi> - 2017-02-14 23:10 +0100
Re: [RFC 07/13] v4l2: device_register_subdev_nodes: allow calling multiple times Laurent Pinchart <laurent.pinchart@ideasonboard.com> - 2017-02-14 23:10 +0100
Re: [RFC 07/13] v4l2: device_register_subdev_nodes: allow calling multiple times Sakari Ailus <sakari.ailus@iki.fi> - 2017-02-14 23:20 +0100
Re: [RFC 07/13] v4l2: device_register_subdev_nodes: allow calling multiple times Pavel Machek <pavel@ucw.cz> - 2017-02-14 23:30 +0100
| From | Pavel Machek <pavel@ucw.cz> |
|---|---|
| Date | 2017-02-14 14:50 +0100 |
| Subject | [RFC 07/13] v4l2: device_register_subdev_nodes: allow calling multiple times |
| Message-ID | <taLEu-2wc-21@gated-at.bofh.it> |
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From: Sebastian Reichel <sre@kernel.org>
Without this, exposure / gain controls do not work in the camera application.
Signed-off-by: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
Signed-off-by: Pavel Machek <pavel@ucw.cz>
---
drivers/media/v4l2-core/v4l2-device.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/media/v4l2-core/v4l2-device.c b/drivers/media/v4l2-core/v4l2-device.c
index f364cc1..b3afbe8 100644
--- a/drivers/media/v4l2-core/v4l2-device.c
+++ b/drivers/media/v4l2-core/v4l2-device.c
@@ -235,6 +235,9 @@ int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev)
if (!(sd->flags & V4L2_SUBDEV_FL_HAS_DEVNODE))
continue;
+ if(sd->devnode)
+ continue;
+
vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
if (!vdev) {
err = -ENOMEM;
--
2.1.4
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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| From | Sakari Ailus <sakari.ailus@iki.fi> |
|---|---|
| Date | 2017-02-14 23:10 +0100 |
| Message-ID | <taTsl-7x0-13@gated-at.bofh.it> |
| In reply to | #1580545 |
Hi Pavel and Sebastian,
On Tue, Feb 14, 2017 at 02:40:00PM +0100, Pavel Machek wrote:
> From: Sebastian Reichel <sre@kernel.org>
>
> Without this, exposure / gain controls do not work in the camera application.
:-)
>
> Signed-off-by: Sebastian Reichel <sre@kernel.org>
> Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
> Signed-off-by: Pavel Machek <pavel@ucw.cz>
> ---
> drivers/media/v4l2-core/v4l2-device.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/media/v4l2-core/v4l2-device.c b/drivers/media/v4l2-core/v4l2-device.c
> index f364cc1..b3afbe8 100644
> --- a/drivers/media/v4l2-core/v4l2-device.c
> +++ b/drivers/media/v4l2-core/v4l2-device.c
> @@ -235,6 +235,9 @@ int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev)
> if (!(sd->flags & V4L2_SUBDEV_FL_HAS_DEVNODE))
> continue;
>
> + if(sd->devnode)
> + continue;
This has been recognised as a problem but you're the first to submit a patch
I believe. Please add an appropriate description. :-)
s/if\(/if (/
I think this one should go in before the rest.
> +
> vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
> if (!vdev) {
> err = -ENOMEM;
--
Kind regards,
Sakari Ailus
e-mail: sakari.ailus@iki.fi XMPP: sailus@retiisi.org.uk
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| From | Laurent Pinchart <laurent.pinchart@ideasonboard.com> |
|---|---|
| Date | 2017-02-14 23:10 +0100 |
| Subject | Re: [RFC 07/13] v4l2: device_register_subdev_nodes: allow calling multiple times |
| Message-ID | <taTsm-7x0-37@gated-at.bofh.it> |
| In reply to | #1580900 |
Hi Sakari,
On Wednesday 15 Feb 2017 00:02:57 Sakari Ailus wrote:
> On Tue, Feb 14, 2017 at 02:40:00PM +0100, Pavel Machek wrote:
> > From: Sebastian Reichel <sre@kernel.org>
> >
> > Without this, exposure / gain controls do not work in the camera
> > application.:
> :-)
> :
> > Signed-off-by: Sebastian Reichel <sre@kernel.org>
> > Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
> > Signed-off-by: Pavel Machek <pavel@ucw.cz>
> > ---
> >
> > drivers/media/v4l2-core/v4l2-device.c | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/media/v4l2-core/v4l2-device.c
> > b/drivers/media/v4l2-core/v4l2-device.c index f364cc1..b3afbe8 100644
> > --- a/drivers/media/v4l2-core/v4l2-device.c
> > +++ b/drivers/media/v4l2-core/v4l2-device.c
> > @@ -235,6 +235,9 @@ int v4l2_device_register_subdev_nodes(struct
> > v4l2_device *v4l2_dev)
> > if (!(sd->flags & V4L2_SUBDEV_FL_HAS_DEVNODE))
> > continue;
> >
> > + if(sd->devnode)
> > + continue;
>
> This has been recognised as a problem but you're the first to submit a patch
> I believe. Please add an appropriate description. :-)
>
> s/if\(/if (/
>
> I think this one should go in before the rest.
But how can this happen ? Is v4l2_device_register_subdev_nodes() called
multiple times ? Do we want to allow that ?
> > +
> > vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
> > if (!vdev) {
> > err = -ENOMEM;
--
Regards,
Laurent Pinchart
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| From | Sakari Ailus <sakari.ailus@iki.fi> |
|---|---|
| Date | 2017-02-14 23:20 +0100 |
| Message-ID | <taTC2-7Be-15@gated-at.bofh.it> |
| In reply to | #1580903 |
Hi Laurent, On Wed, Feb 15, 2017 at 12:06:17AM +0200, Laurent Pinchart wrote: > Hi Sakari, > > On Wednesday 15 Feb 2017 00:02:57 Sakari Ailus wrote: > > On Tue, Feb 14, 2017 at 02:40:00PM +0100, Pavel Machek wrote: > > > From: Sebastian Reichel <sre@kernel.org> > > > > > > Without this, exposure / gain controls do not work in the camera > > > application.: > > :-) > > : > > > Signed-off-by: Sebastian Reichel <sre@kernel.org> > > > Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com> > > > Signed-off-by: Pavel Machek <pavel@ucw.cz> > > > --- > > > > > > drivers/media/v4l2-core/v4l2-device.c | 3 +++ > > > 1 file changed, 3 insertions(+) > > > > > > diff --git a/drivers/media/v4l2-core/v4l2-device.c > > > b/drivers/media/v4l2-core/v4l2-device.c index f364cc1..b3afbe8 100644 > > > --- a/drivers/media/v4l2-core/v4l2-device.c > > > +++ b/drivers/media/v4l2-core/v4l2-device.c > > > @@ -235,6 +235,9 @@ int v4l2_device_register_subdev_nodes(struct > > > v4l2_device *v4l2_dev) > > > if (!(sd->flags & V4L2_SUBDEV_FL_HAS_DEVNODE)) > > > continue; > > > > > > + if(sd->devnode) > > > + continue; > > > > This has been recognised as a problem but you're the first to submit a patch > > I believe. Please add an appropriate description. :-) > > > > s/if\(/if (/ > > > > I think this one should go in before the rest. > > But how can this happen ? Is v4l2_device_register_subdev_nodes() called > multiple times ? Do we want to allow that ? A driver could do this even accidentally. It's much better to do the right thing than to start corrupting system memory sooner or later. In the future we'll need to be able to dynamically register device nodes after the registration of the original device nodes in a media device has completed anyway. I don't think this would be the means for that though. What happens here though is that both the video bus switch and isp notifiers completing will call the function, thus ending up trying to register many of the nodes twice. Philipp had a different approach to the problem --- postponing the complete until add the sub-devices have been bound. The patch is called "v4l2-async: allow subdevices to add further subdevices to the notifier waiting list". -- Kind regards, Sakari Ailus e-mail: sakari.ailus@iki.fi XMPP: sailus@retiisi.org.uk
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| From | Pavel Machek <pavel@ucw.cz> |
|---|---|
| Date | 2017-02-14 23:30 +0100 |
| Message-ID | <taTLI-7Fr-37@gated-at.bofh.it> |
| In reply to | #1580900 |
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On Wed 2017-02-15 00:02:57, Sakari Ailus wrote: > Hi Pavel and Sebastian, > > On Tue, Feb 14, 2017 at 02:40:00PM +0100, Pavel Machek wrote: > > From: Sebastian Reichel <sre@kernel.org> > > > > Without this, exposure / gain controls do not work in the camera application. > > :-) > > > > > Signed-off-by: Sebastian Reichel <sre@kernel.org> > > Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com> > > Signed-off-by: Pavel Machek <pavel@ucw.cz> > > --- > > drivers/media/v4l2-core/v4l2-device.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/drivers/media/v4l2-core/v4l2-device.c b/drivers/media/v4l2-core/v4l2-device.c > > index f364cc1..b3afbe8 100644 > > --- a/drivers/media/v4l2-core/v4l2-device.c > > +++ b/drivers/media/v4l2-core/v4l2-device.c > > @@ -235,6 +235,9 @@ int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev) > > if (!(sd->flags & V4L2_SUBDEV_FL_HAS_DEVNODE)) > > continue; > > > > + if(sd->devnode) > > + continue; > > This has been recognised as a problem but you're the first to submit a patch > I believe. Please add an appropriate description. :-) Ugh. Will try :-). > s/if\(/if (/ > > I think this one should go in before the rest. Easy enough, and I'll move it to the first in the series. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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