[linux-dvb] My Twinhan DVB-T CI won't tune

Jukka Tastula jukka.tastula at kotinet.com
Mon Jun 20 03:38:18 CEST 2005

On Monday 20 June 2005 03:14, Manu Abraham wrote:
> Tell me, how often do you see the "bailout from previous error"
> message.. ? Does this hinder the speed of your zap/scan ?

Every ten minutes or something, not very often but it happens.
I didn't test scanning at all, I just used vdr with the channels.conf I 
already had and the messages show up while watching something. I have no 
idea of course what vdr is doing in the background. 

I set the cards up so that vdr always uses the same card for the same 
frequency so there's no need to tune every time I change from a frequency 
to another.

> How often does this messages appear for you ? During a scan or a szap ..
> ? I presume it is during a scan only..

Just running tzap and keeping it going will trigger the message. The rate 
seems somewhat random, sometimes there are 20 in a minute and sometimes 
none. Not too many all together though. 

> To cross-verify it, i had a posted a set of patches a while earlier
> today .. The last patch logically reduces the chance for that error.
> Can you try that out too.. ? But you would require the entire set of

With these patches I now have another new message. Tzapping to a channel 
gives me a lock nicely and as fast as ever but the numbers seem a bit off 

status 1f | signal 5400 | snr 5f00 | ber bfb05c80 | unc b7e8a28a | 

also while this is running dmesg is _filled_ (as in 200 messages in a 
minute) with 

dst_get_signal: Getting Signal strength and other parameters !!!!!!!!

Same happens if I use the femon plugin in vdr.

With these patches I don't seem to be able to get the other messages 
anymore unless I run dvbscan. And yes you are right, there are more of the 
error messages when dvbscan attempts an invalid frequency.

> Now is it specific to your card, you are seeing this error too often, or
> everyone is seeing this too often.. The reason why i ask is, on all my 4
> variants, it happens in the case when trying to tune to a non-existant
> frequency/polarity..
> Is it the same case with you ?

With the vanilla cvs the messages just keep coming, it doesn't seem to 
matter what I tune to or with.

> Would it be better if i just ignore these errors ? And make it dependant
> upon the debug module parameter ?

So far I haven't noticed any ill effects from whatever is causing the 
messages to appear but I really haven't tested it very much; spent the 
whole day reinstalling the system after a broken memory module trashed the 
root fs.

> One question that i forgot to ask you is which card do you have ? I mean 
> model number and device_id ..

I have no idea what the model number is. The package says chaintech 
dtt-1000 but beyond that I really have no clue at all. 

Linux video capture interface: v1.00
bttv: driver version 0.9.15 loaded
bttv: using 8 buffers with 2080k (520 pages) each for capture
bttv: Bt8xx card found (0).
ACPI: PCI Interrupt 0000:00:08.0[A] -> GSI 16 (level, low) -> IRQ 16
bttv0: Bt878 (rev 17) at 0000:00:08.0, irq: 16, latency: 32, mmio: 
bttv0: detected: ChainTech digitop DST-1000 DVB-S [card=113], PCI subsystem 
ID is 270f:fc00
bttv0: using: Twinhan DST + clones [card=113,autodetected]
bttv0: using tuner=4
bttv0: add subdevice "dvb0"
bt878: Bt878 AUDIO function found (0).
ACPI: PCI Interrupt 0000:00:08.1[A] -> GSI 16 (level, low) -> IRQ 16
bt878(0): Bt878 (rev 17) at 00:08.1, irq: 16, latency: 32, memory: 
DVB: registering new adapter (bttv0).
dst_get_device_id: Recognise [DTTDIG]
DST type : terrestrial
DST type flags : 0x10 firmware version = 2
DVB: registering frontend 0 (DST DVB-T)...

It just likes to say it's DVB-S but it's really a DVB-T card. 

0000:00:08.0 0400: 109e:036e (rev 11)
        Subsystem: 270f:fc00
        Flags: bus master, medium devsel, latency 32, IRQ 16
        Memory at e8111000 (32-bit, prefetchable) [size=4K]
        Capabilities: [44] Vital Product Data
        Capabilities: [4c] Power Management version 2

0000:00:08.1 0480: 109e:0878 (rev 11)
        Subsystem: 270f:fc00
        Flags: bus master, medium devsel, latency 32, IRQ 16
        Memory at e8114000 (32-bit, prefetchable) [size=4K]
        Capabilities: [44] Vital Product Data
        Capabilities: [4c] Power Management version 2

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