[linux-dvb] chaintech dvb-t card

[Jukka Tastula <jukka.tastula@kotinet.com>]

Reading the archives I get the idea that at least someone in Finland has 
managed to get a chaintech digitop dtt-1000 dvb-t card working? I've been 
trying to make this thing work for weeks now and it just doesn't like me. 

It's a conexant fusion 878a based thing. Looking at the card I can also see 
a NxtWave communications Nxt 6000 chip on it, but the nxt6000 module 
doesn't seem to do anything when loaded. There's also one jumper on the 
card and I haven't a clue what it's for, doesn't seem to be documented 
anywhere. Probably not very important. I uploaded a couple of pictures of 
the card to http://www.kotinet.com/jukka.tastula/dtt/ in case anyone wants 
to have a look at this great source of frustration.

Anyway, the card shows up in lspci as a booktree corporation bt878 video 
capture (and audio). I read the tiny helps included with the kernel and 
following those instructions I load bttv, dvb-bt878 and dst. I tried 
loading the bttv module with card=0x68 but that just hangs the whole 
system so 0x71 it is then. Looking at the messages from dst module 
everything appears to be just fine, it correctly detects the card as dvb-t 
(even though bttv says "ChainTech digitop DST-1000 DVB-S", what's up with 
that?).

Tuning to a channel with tzap works perfectly, gets a lock in a second or 
two at most. I get the feeling those ber and unc values are completely 
bogus though. 

Then the real problem appears: the picture is either completely 
unrecognizable or comes up perfect for a second and then breaks up again 
completely. Sometimes it stays for a few seconds with only some small 
visible glitches, sometimes even up to a full minute but I still wouldn't 
say that minute was really watchable. It's as if the signal was drifting 
somehow in and out of phase/sync or something, like a bad vhs. This 
happens with both muxes I get here, the one broadcasted at higher 
frequency (yle) is maybe a little bit worse. Can't really tell they're 
both so bad you can't make sense of them anyway.

I tried the dst module options for dst_type_flags, setting it to 1 makes 
tuning stop working completely, 2 breaks the picture even worse and it's 
really slow to get data off the card, 3 doesn't tune again of course and 
apparently 4 isn't for dvb-t at all. I really hoped 2 would be the magic 
option to fix all my problems but unfortunately it just made everything 
worse. Setting the value to 0 didn't really seem to change anything.

The reception should be just fine, I've used a set top box and the picture 
is perfect with it. Less than one glitch/hour. 

Anyone have any clues they'd like to share? Is this card broken/unsupported 
or just require insane signal strength? What driver versions should I be 
using with this thing? I've only tried the ones with 2.6.7 so far.
Linux video capture interface: v1.00
bttv: driver version 0.9.14 loaded
bttv: using 8 buffers with 2080k (520 pages) each for capture
bttv: Bt8xx card found (0).
PCI: Found IRQ 5 for device 0000:00:09.0
PCI: Sharing IRQ 5 with 0000:00:09.1
bttv0: Bt878 (rev 17) at 0000:00:09.0, irq: 5, latency: 32, mmio: 0xe2000000
bttv0: detected: ChainTech digitop DST-1000 DVB-S [card=113], PCI subsystem ID is 270f:fc00
bttv0: using: Twinhan DST + clones [card=113,insmod option]
bttv0: using tuner=4
bttv0: add subdevice "dvb0"
bt878: AUDIO driver version 0.0.0 loaded
bt878: Bt878 AUDIO function found (0).
PCI: Found IRQ 5 for device 0000:00:09.1
PCI: Sharing IRQ 5 with 0000:00:09.0
bt878(0): Bt878 (rev 17) at 00:09.1, irq: 5, latency: 32, memory: 0xe2001000
dvb_bt8xx_init: unknown card_id found FC00270F
dvb_bt8xx_init: bttv type set to Twinhan DST
attach: checking "ISA main adapter"
attach: checking "bt878 #0 [hw]"
find by pci: checking "bt878 #0 [hw]"
attach: "bt878 #0 [hw]", to card 0
DVB: registering new adapter (DST).
DVB: register adapter0/demux0 @ minor: 4 (0x04)
DVB: register adapter0/dvr0 @ minor: 5 (0x05)
DVB: register adapter0/net0 @ minor: 7 (0x07)
dst_attach: check ci
bt878 find by dvb adap: checking "DST"
read_dst reply is 0xff
dst_wait_dst_ready: dst wait ready after 0
read_dst reply is 0x20
dst_check_ci: recognize DTTDIG
DST type : terrestial TV
DST type flags :
dst_attach: register dst dcbf3a8c bt e098d180 i2c d9a967e8
dvb_register_frontend
DVB: registering frontend 0:0 (DST TERR)...
DVB: register adapter0/frontend0 @ minor: 3 (0x03)
Subtv:482000000:INVERSION_AUTO:BANDWIDTH_8_MHZ:FEC_2_3:FEC_NONE:QAM_64:TRANSMISSION_MODE_8K:GUARD_INTERVAL_1_8:HIERARCHY_NONE:353:609:97

using '/dev/dvb/adapter0/frontend0' and '/dev/dvb/adapter0/demux0'
tuning to 482000000 Hz
status 1f | signal 3f00 | snr 5800 | ber 00000004 | unc 00000000 | FE_HAS_LOCK
status 1f | signal 3e00 | snr 4c00 | ber 00000004 | unc 00000000 | FE_HAS_LOCK
status 1f | signal 3d00 | snr 4000 | ber 00000004 | unc 00000000 | FE_HAS_LOCK
status 1f | signal 3d00 | snr 4a00 | ber 00000004 | unc 00000000 | FE_HAS_LOCK
00:09.0 Multimedia video controller: Brooktree Corporation Bt878 Video Capture (rev 11)
        Subsystem: Chaintech Computer Co. Ltd: Unknown device fc00
        Flags: bus master, medium devsel, latency 32, IRQ 5
        Memory at e2000000 (32-bit, prefetchable) [size=4K]
        Capabilities: <available only to root>

00:09.1 Multimedia controller: Brooktree Corporation Bt878 Audio Capture (rev 11)
        Subsystem: Chaintech Computer Co. Ltd: Unknown device fc00
        Flags: bus master, medium devsel, latency 32, IRQ 5
        Memory at e2001000 (32-bit, prefetchable) [size=4K]
        Capabilities: <available only to root>