[linux-dvb] cx18 - dmesg errors and ir transmit

Andy Walls awalls at radix.net
Mon Jun 16 00:04:32 CEST 2008

On Sun, 2008-06-15 at 08:05 -0400, Brandon Jenkins wrote:
> I use SageTV and upon launch it initializes the adapters resulting in
> the following error messages in dmesg:
> [   36.371502] compat_ioctl32: VIDIOC_G_EXT_CTRLSioctl32(java:7613):
> Unknown cmd fd(13) cmd(c0185647){t:'V';sz:24} arg(caafeaf0) on
> /dev/video1
> [   36.373068] compat_ioctl32: VIDIOC_S_AUDIOioctl32(java:7613):
> Unknown cmd fd(13) cmd(40345622){t:'V';sz:52} arg(caaffbfc) on
> /dev/video1
> [   29.311447] compat_ioctl32: VIDIOC_G_EXT_CTRLSioctl32(java:7613):
> Unknown cmd fd(18) cmd(c0185647){t:'V';sz:24} arg(caafeaf0) on
> /dev/video0
> [   29.312857] compat_ioctl32: VIDIOC_S_AUDIOioctl32(java:7613):
> Unknown cmd fd(18) cmd(40345622){t:'V';sz:52} arg(caaffbfc) on
> /dev/video0

The general V4L2 function used by cx18:


doesn't support these ioctls.  The absence of support is larger than
just for cx18.  The following command roughly shows all the drivers that
rely on v4l_compat_ioctl32():

$ grep -Rl v4l_compat_ioctl32 linux/drivers/media/* 

If really needed, I guess one could add the ioctls one needs to the code
in compat_ioctl32.c.

> I contacted SageTV about the error and was told they don't affect
> anything, but I would like to make sure that is the case.

Only the SageTV authors are in a position to easily tell you if the
unimplemented ioctls matter or not for what SageTV is trying to do.

(Of course if they don't affect anything, why are they doing them? ;] )

> Also, I have noticed a new message in dmesg indicating that ir
> transmitters may now be accessible? Is there anything I need to do to
> make use of them?
> tveeprom 2-0050: has no radio, has IR receiver, has IR transmitter

The IR on the HVR-1600 (a Zilog Z8F0811 microcontroller) is very much
like that of the PVR-150.  From what I can tell, it even appears to be
at the same i2c address. 

This previous message also indicates the PVR-150/500 IR is very similar
to the HVR-1600:

Right now the cx18 driver has omitted some code present in ivtv related
to explicit reset of the IR microcontroller.  It shouldn't be hard to
add back that reset code,  if needed. 

I haven't had a chance to try the IR blaster out yet (it was on my todo
list before Feb 2009).  "Mark's brain dump" has a modified lirc package
for the PVR-150 IR blaster:


It's probably a good starting point.  There are likely to be differences
though, as the cx23418 has 2 I2C buses where the cx23416 only has 1 I2C

It looks like you're blazing a trail, as I can't find any documentation
on the 'net by anyone who has done this with a HVR-1600.  If lirc_i2c,
available with the normal lirc distribution for IR receive, can detect
the Z8F0811, you've probably got a good start.


> Thanks!
> Brandon

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