Re: DVB nGene CI : TS Discontinuities issues

[Issa Gorissen <flop.m@usa.net>]

On 11/05/11 15:12, Issa Gorissen wrote:
> From: Ralph Metzler <rjkm@metzlerbros.de>
>> Issa Gorissen writes:
>>  > Could you please take a look at the cxd2099 issues ?
>>  > 
>>  > I have attached a version with my changes. I have tested a lot of
>>  > different settings with the help of the chip datasheet.
>>  > 
>>  > Scrambled programs are not handled correctly. I don't know if it is the
>>  > TICLK/MCLKI which is too high or something, or the sync detector ? Also,
>>  > as we have to set the TOCLK to max of 72MHz, there are way too much null
>>  > packets added. Is there a way to solve this ?
>>
>> I do not have any cxd2099 issues.
>> I have a simple test program which includes a 32bit counter as payload 
>> and can pump data through the CI with full speed and have no packet
>> loss. I only tested decoding with an ORF stream and an Alphacrypt CAM
>> but also had no problems with this.
>>
>> Please take care not to write data faster than it is read. Starting two
>> dds will not guarantee this. To be certain you could write a small
>> program which never writes more packets than input buffer size minus
>> the number of read packets (and minus the stuffing null packets on ngene).
>>
>> Before blaming packet loss on the CI data path also please make
>> certain that you have no buffer overflows in the input part of 
>> the sec device.
>> In the ngene driver you can e.g. add a printk in tsin_exchange():
>>
>> if (dvb_ringbuffer_free(&dev->tsin_rbuf) > len) {
>> ...
>> } else
>>     printk ("buffer overflow !!!!\n");
>>
>>
>> Regards,
>> Ralph
Ralph,

Done some more tests, from by test tool, I found out that I have to skip
(rather often) bytes to find the sync one when reading from sec0. I
thought I only needed to do that at the start of the stream, not in the
middle; because I always read/write 188 bytes from it.

Could you share your test code ? I'm finding it difficult to interact
with this sec0 implementation.

Thx
--
Issa