Re: Problems tuning 704J dual DVB-T tuner

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Hello Austin

It is not very recent driver, instead one of the oldest I have written. I rewrote af9013 demod maybe 2 years back in order to minimize I/O.

Have you disabled EIT scanning?

AF9015 dual device, especially the one with mxl5005s like that, is quite easy to get in state it loses ability to gain lock. Just start making repeatedly tuning attempts using both tuners and it will stop gaining lock after a while. MythTV does it all the time when there is EIT scanning activated.

The root of cause is likely AF9015 firmware. There is still few things which could be done to improve situation:
1) Serialize all the I/O traffic as much as possible
2) Optimize mxl5005s to generate less traffic. Current mxl5005s Linux driver writes all registers one by one for each tuning. I don't remember counts anymore, but it makes af9013 I/O optimization I did quite useless... Look the Windows sniffs, it is only about 10% of I/0 3) Add some logic to AF9015 I2C adapter to block excessive I/O from "bad behaving" app. Lets say measure I2C I/O during one minute and if it exceeds some threshold start returning error code to app. 4) Hack & fix the firmware. That is surely the best alternative, but it is also the most hardest as disassembling and understanding firmware is not very easy task.

X) I am not going to fix any of those. Just use only first tuner.

regards
Antti



On 07/10/2013 12:23 AM, Austin Spreadbury wrote:
Dear List,

I wonder if anyone can help me.

I have a problem with the AzureWave 704J dual tuner that has developed
recently.  I am using it with Mythbuntu 12.04.1 LTS, at the latest
patch level, but it is persistently failing to record.  It can be made
to work for a single recording, or maybe two, by running the DVB scan
tool on both
adapters corresponding to the tuner - the first scan on adapter 0
fails, subsequent ones on 0 and 1 succeed.

"uname -a" on my system produces this:  Linux mythmk2 3.2.0-43-generic
#68-Ubuntu SMP Wed May 15 03:33:33 UTC 2013 x86_64 x86_64 x86_64
GNU/Linux

It's not mythtv that has the problem - zap fails too, the first time,
but subsequently succeeds.  The attached files show debug logs from
the af9015 driver
- 1.txt is a failed zap to a channel on adapter 0
- 2.txt is a successful zap on adapter 1
- 3.txt is a successful zap on adapter 0.
They were done in that order.

Any ideas?

Thanks,
Austin.



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