Re: CX23103 Video Grabber seems to be supported by cx231xx driver
Hi Florian,
On 07/12/2013 06:26 PM, Florian Streibelt wrote:
Hi,
the chip CX23103 that is used in various devices sold e.g. in germany works
with the cx231xx stock driver.
The author of that driver is not reachable via the email adress stated in the
source file: srinivasa.de...@conexant.com
[ host cnxtsmtp1.conexant.com [198.62.9.252]: 550 5.1.1
srinivasa.de...@conexant.com: Recipient address rejected: User unknown in
relay recipient table]
Yeah, I suspect he left Conexant. For all practical purposes that leaves me as
the maintainer for my sins.
In drivers/media/video/cx231xx/cx231xx-cards.c the struct usb_device_id
cx231xx_id_table[] needs these lines added:
{USB_DEVICE(0x1D19, 0x6109),
.driver_info = CX231XX_BOARD_PV_XCAPTURE_USB},
That looks OK.
While the change is minimal due to the fact that no real technical
documentation is available on the chip the support was guessed - but worked
for video.
The videostream can pe played using mplayer tv:///0 - proof:
http://streibelt.de/blog/2013/06/23/kernel-patch-for-cx23103-video-grabber-linux-support/
However when trying to capture audio using audacity while playing the video
stream in mplayer my system locked (no message in syslog, complete freeze).
I've no idea what is happening here. It has probably to do with the board setup,
although there isn't all that much that you can change there that relates to
audio.
Try using 'arecord' instead of audicity. The arecord tool is more low-level, so
it will be interesting to know if it behaves differently.
Besides that the only thing I can think of is just to try and add printk's to
cx231xx-audio.c and see where things go boom.
A useful trick there is to add a mdelay(5) or so after the printk to give the
system time to write to the kernel log.
Be aware that I consider this driver to be flaky, so I would not at all be
surprised if there are bugs lurking in the code.
Regards,
Hans
I posted this one month ago to this list without any reaction so I ask if
this is the correct way to get that grabber really supported.
I am willing to do any tests neccessary and try out patches.
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Re: CX23103 Video Grabber seems to be supported by cx231xx driver
On Sun, 14 Jul 2013 11:23:46 +0200
Hans Verkuil hverk...@xs4all.nl wrote:
Hi Florian,
On 07/12/2013 06:26 PM, Florian Streibelt wrote:
Hi,
the chip CX23103 that is used in various devices sold e.g. in germany works
with the cx231xx stock driver.
The author of that driver is not reachable via the email adress stated in
the source file: srinivasa.de...@conexant.com
[ host cnxtsmtp1.conexant.com [198.62.9.252]: 550 5.1.1
srinivasa.de...@conexant.com: Recipient address rejected: User unknown
in relay recipient table]
Yeah, I suspect he left Conexant. For all practical purposes that leaves me as
the maintainer for my sins.
heh - also means a patch should remove the wrong email adress/change the
maintainers in the source?
In drivers/media/video/cx231xx/cx231xx-cards.c the struct usb_device_id
cx231xx_id_table[] needs these lines added:
{USB_DEVICE(0x1D19, 0x6109),
.driver_info = CX231XX_BOARD_PV_XCAPTURE_USB},
That looks OK.
Only if the board layout is different :/
There is no information from the vendor, they don't even reply to messages via
the contact form, of course.
While the change is minimal due to the fact that no real technical
documentation is available on the chip the support was guessed - but worked
for video.
The videostream can pe played using mplayer tv:///0 - proof:
http://streibelt.de/blog/2013/06/23/kernel-patch-for-cx23103-video-grabber-linux-support/
However when trying to capture audio using audacity while playing the video
stream in mplayer my system locked (no message in syslog, complete freeze).
I've no idea what is happening here. It has probably to do with the board
setup,
although there isn't all that much that you can change there that relates to
audio.
hm. maybe disable it - currently my time budget is negative - so I cannot
really work on this.
Try using 'arecord' instead of audicity. The arecord tool is more low-level,
so
it will be interesting to know if it behaves differently.
I'll try - the problem is the complete system freeze - I'll see if I can setup
a system with serial console for the kernel log
Besides that the only thing I can think of is just to try and add printk's to
cx231xx-audio.c and see where things go boom.
yup. If I had the time.
A useful trick there is to add a mdelay(5) or so after the printk to give the
system time to write to the kernel log.
ok
Be aware that I consider this driver to be flaky, so I would not at all be
surprised if there are bugs lurking in the code.
Hum. Because of code quality or due to the missing documentation from the
vendor?
If you have any documents on the chip I would be happy.
/Florian
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Re: CX23103 Video Grabber seems to be supported by cx231xx driver
On Sun, Jul 14, 2013 at 9:23 AM, Florian Streibelt flor...@inet.tu-berlin.de wrote: Be aware that I consider this driver to be flaky, so I would not at all be surprised if there are bugs lurking in the code. Hum. Because of code quality or due to the missing documentation from the vendor? While this is all too common for vendors, it really isn't a reasonable assertion in this case. Conexant (the chip vendor) wrote the original driver, and they have been very supportive in the past. They provided documentation (under NDA) and reference designs at no cost. They've also answered questions I've had in the past regarding the chip and you'll also note that the email address of the maintainer was a Conexant engineer until he left the company. Regarding the flakiness, there indeed have been some reliability problems - some of them were in the original driver sources, a couple I introduced doing the cleanup work to get it upstream (and long ago fixed), and some were regressions introduced after the driver went upstream. It's tough maintaining a driver on an ongoing basis that supports many different cards from different vendors, in particular since individuals making changes to the driver to make it work with some new device, don't have all of the other products to test with (to ensure regressions aren't introduced). These drivers also tend to suffer from bitrot. If they aren't actively being used by many people and if there isn't a developer who actively maintains the driver, then regressions sneak in there and go unnoticed for months/years. If you have any documents on the chip I would be happy. I don't think there are any documents that aren't under NDA. That said, you don't need the register docs to debug a system hang. If you don't have the time to jam a few printk() statements into the source, then there's no point in going through the effort to get you docs. Your best bet at this point is probably to wait [indefinitely] for some developer who has a need for the device to work to stumble across the problem and debug it. You get what you pay for. Devin -- Devin J. Heitmueller - Kernel Labs http://www.kernellabs.com -- 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: CX23103 Video Grabber seems to be supported by cx231xx driver
On Sun, 14 Jul 2013 09:41:40 -0400 Devin Heitmueller dheitmuel...@kernellabs.com wrote: said, you don't need the register docs to debug a system hang. If you don't have the time to jam a few printk() statements into the source, then there's no point in going through the effort to get you docs. heh - yea. The thing is that I don't want to star yet another project which ends in frustration because I have to guess and miss documents. I'll see if I find the time to put some printk's and find a debug system with external logging - but this wil take some time (currently writing my diploma thesis)... /Florian -- 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
