[linux-dvb] Re: Mantis VP-1027/VP-1033/VP-1034/VP-2033/VP-3033

Pauli Borodulin Pauli at Borodulin.fi
Tue Oct 10 23:16:12 CEST 2006

Pauli Borodulin wrote:
> [...]
> The problem is: In the beginning the driver is able to communicate with
> cu1216 using I2C. For example, the driver is able to check that the
> demodulator is there using cu1216_readreg(). As soon as DMA is started (you
> get "mantis start feed & dma" in your kernel log), all i2c reading and
> writing fails. Every read returns 0. I have not yet found out why. You can
> verify this by adding
> [...]

I made a quick and dirty hack and commented out the contents of the
functions mantis_dma.c/mantis_dma_start() and mantis_dma.c/mantis_dma_stop()
and now I2C seems to works ok. This will totally break the driver, so it's
not a fix. I did it because I was curios whether it would make any
difference, and it did. I then tried uncommenting lines in
mantis_dma_start() one by one starting from the beginning, and found out
that the line


was the one that triggered the bug. I have no knowledge on the hardware in
question (I don't have any datasheets etc.), so I have no idea what I should
do next. There's also some bugs in the cu1216 driver, but it's no use to
debug them before the DMA(?) problem is fixed.

Pauli Borodulin <pauli at borodulin.fi>
gsm. +358 (0) 44 5555 381

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 250 bytes
Desc: OpenPGP digital signature
Url : http://www.linuxtv.org/pipermail/linux-dvb/attachments/20061011/35a11d73/signature.pgp

More information about the linux-dvb mailing list