[linux-dvb] dvr device reading hangs

Krzysztof Matula km at km.apnet.pl
Thu Feb 17 22:38:46 CET 2005

nuclearcat wrote:
>>>SkyStar2, kernel: 2.6.10-1.760_FC3
>>>I'm waiting for the dvr fd with select, and then if FD_ISSET I issue a
>>>read() call to it. Usually it works perfectly well, but sometimes, 
>>>especially when other thread is performing multiple repeated tunings on
>>>the forntend the read() blocks infinitely until the process is killed...
>>Open with O_NONBLOCK.

Will it help? I assume the read() will not block, but will it actually 
receive any data?

>>It has been reported a few times that the skystar2 driver has a bug where
>>it stops outputting data. I assume a race in irq/dma handling, but
>>didn't have the time to investigate (I also don't have hardware).
>>You could do 'cat /proc/interrupts' to see if there are still irqs
>>when your read() hangs.

The counter stops.
The frontend reports a locked state however.

Any suggestions how to investigate it further?

> I had similar thing, and investigate, thats STV0299B version (revision
> 2.6) stopping if signal is weak, and there uncorrected/corrected
> errors. Which revision of SS2 is used?

Revision 2.6 C:

drivers/media/dvb/b2c2/skystar2.c: FlexCopIIB(rev.195) chip found
drivers/media/dvb/b2c2/skystar2.c: the chip has 38 hardware filters
DVB: registering new adapter (SkyStar2).
DVB: registering frontend 0 (ST STV0299 DVB-S)...


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