Re: [RFCv1 API PATCH 4/4] tuner-core: map audmode to STEREO for radio devices.
On Wed September 26 2012 04:29:33 Mauro Carvalho Chehab wrote:
Em Tue, 25 Sep 2012 15:45:00 +0200
Hans Verkuil hansv...@cisco.com escreveu:
On Tue 25 September 2012 15:33:40 Mauro Carvalho Chehab wrote:
Em Fri, 14 Sep 2012 13:15:36 +0200
Hans Verkuil hans.verk...@cisco.com escreveu:
Fixes a v4l2-compliance error: setting audmode to a value other than
mono
or stereo for a radio device should map to MODE_STEREO.
Signed-off-by: Hans Verkuil hans.verk...@cisco.com
---
drivers/media/v4l2-core/tuner-core.c |5 -
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/media/v4l2-core/tuner-core.c
b/drivers/media/v4l2-core/tuner-core.c
index b5a819a..ea71371 100644
--- a/drivers/media/v4l2-core/tuner-core.c
+++ b/drivers/media/v4l2-core/tuner-core.c
@@ -1235,8 +1235,11 @@ static int tuner_s_tuner(struct v4l2_subdev *sd,
struct v4l2_tuner *vt)
if (set_mode(t, vt-type))
return 0;
- if (t-mode == V4L2_TUNER_RADIO)
+ if (t-mode == V4L2_TUNER_RADIO) {
t-audmode = vt-audmode;
+ if (t-audmode V4L2_TUNER_MODE_STEREO)
+ t-audmode = V4L2_TUNER_MODE_STEREO;
NACK. It is not a core's task to fix driver's bugs. It would be ok to
have here a
WARN_ON(), but, if a driver is reporting a wrong radio audmode, the fix
should be
there at the drivers, and not here at the core.
tuner-core *is* the driver.
Not really... it is a driver's glue between the real I2C driver and the bridge
driver.
A bridge driver just passes v4l2_tuner on to the
subdev driver(s), and it is the subdev driver such as tuner-core that needs
to
process the audmode as specified by the user. Which in this case means
mapping
audmodes that are invalid when in radio mode to something that is valid as
per
the spec.
Well, when the user is requesting an invalid mode, it should just return
-EINVAL.
It makes sense to add a check there at tuner-core to reject audmode if
userspace
is requesting, for example, a second language[1].
My interpretation of the spec is that it will map invalid audmodes to valid
audmodes.
From the VIDIOC_S_TUNER documentation:
The selected audio mode, see Table A.89, “Tuner Audio Modes” for valid values.
The
audio mode does not affect audio subprogram detection, and like a control it
does not
automatically change unless the requested mode is invalid or unsupported. See
Table
A.90, “Tuner Audio Matrix” for possible results when the selected and received
audio
programs do not match.
So my interpretation is that if an audmode is provided that is not valid for the
given device, then the device maps it to something valid rather than returning
an
error. The error code list only states that -EINVAL is returned if the index
field
is out-of-bounds, not for invalid audmodes.
I think this makes sense as well, otherwise apps would have to laboriously check
which audmodes are supported before they can call S_TUNER. It's much easier to
just give the 'best' audmode and let the driver downgrade if it isn't supported.
This is what happens today anyway, so we can't change that behavior. But the one
thing that should work is that the actual audmode is returned when calling
G_TUNER,
which is why the current tuner-core fails with v4l2-compliance.
[1] Yet, I think that digital audio standards allow more than one audio
channels.
So, this may require to be pushed down into the drivers in some future.
What is invalid actually depends on the device. For example, AM ISA drivers
don't support stereo. Ok, all tuners supported by tuner-core are FM. Even so,
some of them may not support stereo[2].
[2] afaikt, some designs with tuner xc2028 don't support stereo. The driver
currently
doesn't handle such border cases, but the point is that such checks should
happen
at driver's level.
99% of all those tuner drivers do support stereo, so let's do this simple check
in tuner-core so we don't have to fix all of them. The spec is also clear that
radio devices only support mono or stereo audmodes. Those tuner drivers that
only support mono can easily enforce that explicitly. Or they could, if
tuner-core
would copy back the audmode value after calling analog_ops-set_params().
Just as we do basic checks in v4l2-ioctl.c, so we can do basic checks in
tuner-core
as well.
Regards,
Hans
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Re: [RFCv1 API PATCH 4/4] tuner-core: map audmode to STEREO for radio devices.
Em Wed, 26 Sep 2012 09:03:13 +0200
Hans Verkuil hverk...@xs4all.nl escreveu:
On Wed September 26 2012 04:29:33 Mauro Carvalho Chehab wrote:
Em Tue, 25 Sep 2012 15:45:00 +0200
Hans Verkuil hansv...@cisco.com escreveu:
On Tue 25 September 2012 15:33:40 Mauro Carvalho Chehab wrote:
Em Fri, 14 Sep 2012 13:15:36 +0200
Hans Verkuil hans.verk...@cisco.com escreveu:
Fixes a v4l2-compliance error: setting audmode to a value other than
mono
or stereo for a radio device should map to MODE_STEREO.
Signed-off-by: Hans Verkuil hans.verk...@cisco.com
---
drivers/media/v4l2-core/tuner-core.c |5 -
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/media/v4l2-core/tuner-core.c
b/drivers/media/v4l2-core/tuner-core.c
index b5a819a..ea71371 100644
--- a/drivers/media/v4l2-core/tuner-core.c
+++ b/drivers/media/v4l2-core/tuner-core.c
@@ -1235,8 +1235,11 @@ static int tuner_s_tuner(struct v4l2_subdev
*sd, struct v4l2_tuner *vt)
if (set_mode(t, vt-type))
return 0;
- if (t-mode == V4L2_TUNER_RADIO)
+ if (t-mode == V4L2_TUNER_RADIO) {
t-audmode = vt-audmode;
+ if (t-audmode V4L2_TUNER_MODE_STEREO)
+ t-audmode = V4L2_TUNER_MODE_STEREO;
NACK. It is not a core's task to fix driver's bugs. It would be ok to
have here a
WARN_ON(), but, if a driver is reporting a wrong radio audmode, the fix
should be
there at the drivers, and not here at the core.
tuner-core *is* the driver.
Not really... it is a driver's glue between the real I2C driver and the
bridge
driver.
A bridge driver just passes v4l2_tuner on to the
subdev driver(s), and it is the subdev driver such as tuner-core that
needs to
process the audmode as specified by the user. Which in this case means
mapping
audmodes that are invalid when in radio mode to something that is valid
as per
the spec.
Well, when the user is requesting an invalid mode, it should just return
-EINVAL.
It makes sense to add a check there at tuner-core to reject audmode if
userspace
is requesting, for example, a second language[1].
My interpretation of the spec is that it will map invalid audmodes to valid
audmodes.
From the VIDIOC_S_TUNER documentation:
The selected audio mode, see Table A.89, “Tuner Audio Modes” for valid
values. The
audio mode does not affect audio subprogram detection, and like a control it
does not
automatically change unless the requested mode is invalid or unsupported. See
Table
A.90, “Tuner Audio Matrix” for possible results when the selected and
received audio
programs do not match.
So my interpretation is that if an audmode is provided that is not valid for
the
given device, then the device maps it to something valid rather than
returning an
error. The error code list only states that -EINVAL is returned if the index
field
is out-of-bounds, not for invalid audmodes.
I think this makes sense as well, otherwise apps would have to laboriously
check
which audmodes are supported before they can call S_TUNER. It's much easier to
just give the 'best' audmode and let the driver downgrade if it isn't
supported.
This is what happens today anyway, so we can't change that behavior. But the
one
thing that should work is that the actual audmode is returned when calling
G_TUNER,
which is why the current tuner-core fails with v4l2-compliance.
Ok, you convinced me on that. Please be more verbose at the patch description,
describing why it is falling back to a different mode.
Also, please change that:
+ if (t-audmode V4L2_TUNER_MODE_STEREO)
+ t-audmode = V4L2_TUNER_MODE_STEREO;
to something like:
if (t-audmode != V4L2_TUNER_MODE_STEREO
t-audmode != V4L2_TUNER_MODE_MONO)
t-audmode = V4L2_TUNER_MODE_STEREO;
We use those enums/defines to not having to remember the actual numbers
associated
with them. By using operators like greater/lower than, people will actually
need to
dig into the videodev2.h, in order to know what's covered there.
Besides that, the compiler will likely optimize it to greater than anyway, as
audmode
is unsigned.
[1] Yet, I think that digital audio standards allow more than one audio
channels.
So, this may require to be pushed down into the drivers in some future.
What is invalid actually depends on the device. For example, AM ISA drivers
don't support stereo. Ok, all tuners supported by tuner-core are FM. Even
so,
some of them may not support stereo[2].
[2] afaikt, some designs with tuner xc2028 don't support stereo. The driver
currently
doesn't handle such border cases, but the point is that such checks should
happen
at driver's level.
99% of all those tuner
Re: [RFCv1 API PATCH 4/4] tuner-core: map audmode to STEREO for radio devices.
On Wed 26 September 2012 11:35:27 Mauro Carvalho Chehab wrote:
Em Wed, 26 Sep 2012 09:03:13 +0200
Hans Verkuil hverk...@xs4all.nl escreveu:
On Wed September 26 2012 04:29:33 Mauro Carvalho Chehab wrote:
Em Tue, 25 Sep 2012 15:45:00 +0200
Hans Verkuil hansv...@cisco.com escreveu:
On Tue 25 September 2012 15:33:40 Mauro Carvalho Chehab wrote:
Em Fri, 14 Sep 2012 13:15:36 +0200
Hans Verkuil hans.verk...@cisco.com escreveu:
Fixes a v4l2-compliance error: setting audmode to a value other
than mono
or stereo for a radio device should map to MODE_STEREO.
Signed-off-by: Hans Verkuil hans.verk...@cisco.com
---
drivers/media/v4l2-core/tuner-core.c |5 -
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/media/v4l2-core/tuner-core.c
b/drivers/media/v4l2-core/tuner-core.c
index b5a819a..ea71371 100644
--- a/drivers/media/v4l2-core/tuner-core.c
+++ b/drivers/media/v4l2-core/tuner-core.c
@@ -1235,8 +1235,11 @@ static int tuner_s_tuner(struct v4l2_subdev
*sd, struct v4l2_tuner *vt)
if (set_mode(t, vt-type))
return 0;
- if (t-mode == V4L2_TUNER_RADIO)
+ if (t-mode == V4L2_TUNER_RADIO) {
t-audmode = vt-audmode;
+ if (t-audmode V4L2_TUNER_MODE_STEREO)
+ t-audmode = V4L2_TUNER_MODE_STEREO;
NACK. It is not a core's task to fix driver's bugs. It would be ok to
have here a
WARN_ON(), but, if a driver is reporting a wrong radio audmode, the
fix should be
there at the drivers, and not here at the core.
tuner-core *is* the driver.
Not really... it is a driver's glue between the real I2C driver and the
bridge
driver.
A bridge driver just passes v4l2_tuner on to the
subdev driver(s), and it is the subdev driver such as tuner-core that
needs to
process the audmode as specified by the user. Which in this case means
mapping
audmodes that are invalid when in radio mode to something that is valid
as per
the spec.
Well, when the user is requesting an invalid mode, it should just return
-EINVAL.
It makes sense to add a check there at tuner-core to reject audmode if
userspace
is requesting, for example, a second language[1].
My interpretation of the spec is that it will map invalid audmodes to valid
audmodes.
From the VIDIOC_S_TUNER documentation:
The selected audio mode, see Table A.89, “Tuner Audio Modes” for valid
values. The
audio mode does not affect audio subprogram detection, and like a control
it does not
automatically change unless the requested mode is invalid or unsupported.
See Table
A.90, “Tuner Audio Matrix” for possible results when the selected and
received audio
programs do not match.
So my interpretation is that if an audmode is provided that is not valid
for the
given device, then the device maps it to something valid rather than
returning an
error. The error code list only states that -EINVAL is returned if the
index field
is out-of-bounds, not for invalid audmodes.
I think this makes sense as well, otherwise apps would have to laboriously
check
which audmodes are supported before they can call S_TUNER. It's much easier
to
just give the 'best' audmode and let the driver downgrade if it isn't
supported.
This is what happens today anyway, so we can't change that behavior. But
the one
thing that should work is that the actual audmode is returned when calling
G_TUNER,
which is why the current tuner-core fails with v4l2-compliance.
Ok, you convinced me on that. Please be more verbose at the patch description,
describing why it is falling back to a different mode.
Also, please change that:
+ if (t-audmode V4L2_TUNER_MODE_STEREO)
+ t-audmode = V4L2_TUNER_MODE_STEREO;
to something like:
if (t-audmode != V4L2_TUNER_MODE_STEREO
t-audmode != V4L2_TUNER_MODE_MONO)
t-audmode = V4L2_TUNER_MODE_STEREO;
We use those enums/defines to not having to remember the actual numbers
associated
with them. By using operators like greater/lower than, people will actually
need to
dig into the videodev2.h, in order to know what's covered there.
Besides that, the compiler will likely optimize it to greater than anyway, as
audmode
is unsigned.
[1] Yet, I think that digital audio standards allow more than one audio
channels.
So, this may require to be pushed down into the drivers in some future.
What is invalid actually depends on the device. For example, AM ISA
drivers
don't support stereo. Ok, all tuners supported by tuner-core are FM. Even
so,
some of them may not support stereo[2].
[2] afaikt, some designs with tuner xc2028 don't
Re: [RFCv1 API PATCH 4/4] tuner-core: map audmode to STEREO for radio devices.
Em Fri, 14 Sep 2012 13:15:36 +0200
Hans Verkuil hans.verk...@cisco.com escreveu:
Fixes a v4l2-compliance error: setting audmode to a value other than mono
or stereo for a radio device should map to MODE_STEREO.
Signed-off-by: Hans Verkuil hans.verk...@cisco.com
---
drivers/media/v4l2-core/tuner-core.c |5 -
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/media/v4l2-core/tuner-core.c
b/drivers/media/v4l2-core/tuner-core.c
index b5a819a..ea71371 100644
--- a/drivers/media/v4l2-core/tuner-core.c
+++ b/drivers/media/v4l2-core/tuner-core.c
@@ -1235,8 +1235,11 @@ static int tuner_s_tuner(struct v4l2_subdev *sd,
struct v4l2_tuner *vt)
if (set_mode(t, vt-type))
return 0;
- if (t-mode == V4L2_TUNER_RADIO)
+ if (t-mode == V4L2_TUNER_RADIO) {
t-audmode = vt-audmode;
+ if (t-audmode V4L2_TUNER_MODE_STEREO)
+ t-audmode = V4L2_TUNER_MODE_STEREO;
NACK. It is not a core's task to fix driver's bugs. It would be ok to have here
a
WARN_ON(), but, if a driver is reporting a wrong radio audmode, the fix should
be
there at the drivers, and not here at the core.
+ }
set_freq(t, 0);
return 0;
--
Regards,
Mauro
--
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the body of a message to majord...@vger.kernel.org
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Re: [RFCv1 API PATCH 4/4] tuner-core: map audmode to STEREO for radio devices.
On Tue 25 September 2012 15:33:40 Mauro Carvalho Chehab wrote:
Em Fri, 14 Sep 2012 13:15:36 +0200
Hans Verkuil hans.verk...@cisco.com escreveu:
Fixes a v4l2-compliance error: setting audmode to a value other than mono
or stereo for a radio device should map to MODE_STEREO.
Signed-off-by: Hans Verkuil hans.verk...@cisco.com
---
drivers/media/v4l2-core/tuner-core.c |5 -
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/media/v4l2-core/tuner-core.c
b/drivers/media/v4l2-core/tuner-core.c
index b5a819a..ea71371 100644
--- a/drivers/media/v4l2-core/tuner-core.c
+++ b/drivers/media/v4l2-core/tuner-core.c
@@ -1235,8 +1235,11 @@ static int tuner_s_tuner(struct v4l2_subdev *sd,
struct v4l2_tuner *vt)
if (set_mode(t, vt-type))
return 0;
- if (t-mode == V4L2_TUNER_RADIO)
+ if (t-mode == V4L2_TUNER_RADIO) {
t-audmode = vt-audmode;
+ if (t-audmode V4L2_TUNER_MODE_STEREO)
+ t-audmode = V4L2_TUNER_MODE_STEREO;
NACK. It is not a core's task to fix driver's bugs. It would be ok to have
here a
WARN_ON(), but, if a driver is reporting a wrong radio audmode, the fix
should be
there at the drivers, and not here at the core.
tuner-core *is* the driver. A bridge driver just passes v4l2_tuner on to the
subdev driver(s), and it is the subdev driver such as tuner-core that needs to
process the audmode as specified by the user. Which in this case means mapping
audmodes that are invalid when in radio mode to something that is valid as per
the spec.
So this is a real tuner-core bug, not a bridge driver bug since they don't
generally touch the audmode field, they just pass it along. And the vt-audmode
value comes straight from userspace, not from the bridge driver.
Regards,
Hans
--
To unsubscribe from this list: send the line unsubscribe linux-media in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [RFCv1 API PATCH 4/4] tuner-core: map audmode to STEREO for radio devices.
Em Tue, 25 Sep 2012 15:45:00 +0200
Hans Verkuil hansv...@cisco.com escreveu:
On Tue 25 September 2012 15:33:40 Mauro Carvalho Chehab wrote:
Em Fri, 14 Sep 2012 13:15:36 +0200
Hans Verkuil hans.verk...@cisco.com escreveu:
Fixes a v4l2-compliance error: setting audmode to a value other than mono
or stereo for a radio device should map to MODE_STEREO.
Signed-off-by: Hans Verkuil hans.verk...@cisco.com
---
drivers/media/v4l2-core/tuner-core.c |5 -
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/media/v4l2-core/tuner-core.c
b/drivers/media/v4l2-core/tuner-core.c
index b5a819a..ea71371 100644
--- a/drivers/media/v4l2-core/tuner-core.c
+++ b/drivers/media/v4l2-core/tuner-core.c
@@ -1235,8 +1235,11 @@ static int tuner_s_tuner(struct v4l2_subdev *sd,
struct v4l2_tuner *vt)
if (set_mode(t, vt-type))
return 0;
- if (t-mode == V4L2_TUNER_RADIO)
+ if (t-mode == V4L2_TUNER_RADIO) {
t-audmode = vt-audmode;
+ if (t-audmode V4L2_TUNER_MODE_STEREO)
+ t-audmode = V4L2_TUNER_MODE_STEREO;
NACK. It is not a core's task to fix driver's bugs. It would be ok to have
here a
WARN_ON(), but, if a driver is reporting a wrong radio audmode, the fix
should be
there at the drivers, and not here at the core.
tuner-core *is* the driver.
Not really... it is a driver's glue between the real I2C driver and the bridge
driver.
A bridge driver just passes v4l2_tuner on to the
subdev driver(s), and it is the subdev driver such as tuner-core that needs to
process the audmode as specified by the user. Which in this case means mapping
audmodes that are invalid when in radio mode to something that is valid as per
the spec.
Well, when the user is requesting an invalid mode, it should just return
-EINVAL.
It makes sense to add a check there at tuner-core to reject audmode if userspace
is requesting, for example, a second language[1].
[1] Yet, I think that digital audio standards allow more than one audio
channels.
So, this may require to be pushed down into the drivers in some future.
What is invalid actually depends on the device. For example, AM ISA drivers
don't support stereo. Ok, all tuners supported by tuner-core are FM. Even so,
some of them may not support stereo[2].
[2] afaikt, some designs with tuner xc2028 don't support stereo. The driver
currently
doesn't handle such border cases, but the point is that such checks should
happen
at driver's level.
So this is a real tuner-core bug, not a bridge driver bug since they don't
generally touch the audmode field, they just pass it along. And the
vt-audmode
value comes straight from userspace, not from the bridge driver.
Well, tuner-core is just an unified way to talk to the real tuner device.
The is elsewhere (tuner-simple, tea5***, ...).
IMHO, the better is to put such fix at the real device, instead of hacking the
code with something that doesn't really belong there.
Regards,
Mauro
--
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[RFCv1 API PATCH 4/4] tuner-core: map audmode to STEREO for radio devices.
Fixes a v4l2-compliance error: setting audmode to a value other than mono
or stereo for a radio device should map to MODE_STEREO.
Signed-off-by: Hans Verkuil hans.verk...@cisco.com
---
drivers/media/v4l2-core/tuner-core.c |5 -
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/media/v4l2-core/tuner-core.c
b/drivers/media/v4l2-core/tuner-core.c
index b5a819a..ea71371 100644
--- a/drivers/media/v4l2-core/tuner-core.c
+++ b/drivers/media/v4l2-core/tuner-core.c
@@ -1235,8 +1235,11 @@ static int tuner_s_tuner(struct v4l2_subdev *sd, struct
v4l2_tuner *vt)
if (set_mode(t, vt-type))
return 0;
- if (t-mode == V4L2_TUNER_RADIO)
+ if (t-mode == V4L2_TUNER_RADIO) {
t-audmode = vt-audmode;
+ if (t-audmode V4L2_TUNER_MODE_STEREO)
+ t-audmode = V4L2_TUNER_MODE_STEREO;
+ }
set_freq(t, 0);
return 0;
--
1.7.10.4
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