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Media-Pointer MP-S2 DVB-S2 tuning problem

linux-dvb Doru Marin 1 participant 2 messages Nov 27, 2009 – Apr 2, 2010 Media (V4L/DVB)

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Doru Marin

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Hello,

I tested the experimental driver for Media-Pointer MP-S2 PCIe card and I got very strange timeouts for tunning.
It takes five seconds or more to tune on a channel. By comparison with nGene driver (which tunes faster), this is terrible long time. For demodulation, it uses the same STV0900 demodulator like NetUP Dual Tuner cards.
I'm curious, on NetUP devices, the timeout is similar ?
Can be done anything to improve that ?

Best regards,

Doru Marin

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CX88 TS overflows too often

Hello,

I have a system with two Hauppauge Nova-S-Plus cards and a HVR4000Lite. Very often I'm getting errors like:

cx88[0]/2-mpeg: general errors: 0x00000100
cx88[2]/2-mpeg: general errors: 0x00000100

Digging in the code, I found that is DMA related, meaning TS overflow.

Looking further, I found that for TS handling, FIFO queue size is really small, only 4K, of available 32K.
As long as the DVB-S2 streams are running up to 80Mbps, isn't this value too small a fluent running ?
I presume that these overflows are caused by larger PCI latencies, causing delays in buffer transfers.

As long as these cards are used most of the time for TS handling, isn't there any chance to increase the TS FIFO size ?
Or optionally allocating more for this purpose ? The HVR4000Lite has no video or audio inputs, but there are allocated resources for them, wasted resources.

Regards,

Doru Marin