[linux-dvb] TechnoTrend C-1501 - Locking issues on 388Mhz
klaas de waal
klaas.de.waal at gmail.com
Sun Oct 12 22:21:46 CEST 2008
On Fri, Oct 10, 2008 at 2:36 AM, hermann pitton <hermann-pitton at arcor.de>wrote:
> Hi,
>
> Am Donnerstag, den 09.10.2008, 22:15 +0200 schrieb klaas de waal:
> > Hi Jeremy,
> >
> > I have the Technotrend C-1501 now locking at 388MHz.
> > The table tda827xa_dvbt contains the settings for each frequency
> > segment.
> > The frequency values (first column) are for the frequency plus the
> > IF, so for 388MHz
> > this is 388+5 gives 393 MHz. The table starts a new segment at 390MHz,
> > it then
> > starts to use VCO2 instead of VCO1.
> > I have now (hack, hack) changed the segment start from 390 to 395MHz
> > so
> > that the 388MHz is still tuned with VCO1, and this works OK!!
> > Like this:
> >
> > static const struct tda827xa_data tda827xa_dvbt[] = {
> > { .lomax = 56875000, .svco = 3, .spd = 4, .scr = 0, .sbs =
> > 0, .gc3 = 1},
> > { .lomax = 67250000, .svco = 0, .spd = 3, .scr = 0, .sbs =
> > 0, .gc3 = 1},
> > { .lomax = 81250000, .svco = 1, .spd = 3, .scr = 0, .sbs =
> > 0, .gc3 = 1},
> > { .lomax = 97500000, .svco = 2, .spd = 3, .scr = 0, .sbs =
> > 0, .gc3 = 1},
> > { .lomax = 113750000, .svco = 3, .spd = 3, .scr = 0, .sbs =
> > 1, .gc3 = 1},
> > { .lomax = 134500000, .svco = 0, .spd = 2, .scr = 0, .sbs =
> > 1, .gc3 = 1},
> > { .lomax = 154000000, .svco = 1, .spd = 2, .scr = 0, .sbs =
> > 1, .gc3 = 1},
> > { .lomax = 162500000, .svco = 1, .spd = 2, .scr = 0, .sbs =
> > 1, .gc3 = 1},
> > { .lomax = 183000000, .svco = 2, .spd = 2, .scr = 0, .sbs =
> > 1, .gc3 = 1},
> > { .lomax = 195000000, .svco = 2, .spd = 2, .scr = 0, .sbs =
> > 2, .gc3 = 1},
> > { .lomax = 227500000, .svco = 3, .spd = 2, .scr = 0, .sbs =
> > 2, .gc3 = 1},
> > { .lomax = 269000000, .svco = 0, .spd = 1, .scr = 0, .sbs =
> > 2, .gc3 = 1},
> > { .lomax = 290000000, .svco = 1, .spd = 1, .scr = 0, .sbs =
> > 2, .gc3 = 1},
> > { .lomax = 325000000, .svco = 1, .spd = 1, .scr = 0, .sbs =
> > 3, .gc3 = 1},
> > #ifdef ORIGINAL // KdW test
> > { .lomax = 390000000, .svco = 2, .spd = 1, .scr = 0, .sbs =
> > 3, .gc3 = 1},
> > #else
> > { .lomax = 395000000, .svco = 2, .spd = 1, .scr = 0, .sbs =
> > 3, .gc3 = 1},
> > #endif
> > { .lomax = 455000000, .svco = 3, .spd = 1, .scr = 0, .sbs =
> > 3, .gc3 = 1},
> > etc etc
> >
> > I plan to do a test on the all frequencies in the near future, at
> > least on all the Dutch Ziggo frequencies.
> > Because I cannot test what will happen if the driver is used for DVB-T
> > (what
> > the name of the table suggests) it might be best to make a separate
> > tda827xa_dvbc table.
> >
> > About the timeout messages, they come from the SAA7134 and they happen
> > fairly random. I have looked at debug traces and everytime it happens
> > it
> > does a retry and then succeeds, so I think this can be ignored for the
> > time being.
> > Maybe you can check if the fix/hack also works for you?
> > If there is an official maintainer of this driver, maybe he can
> > comment?
> >
> > Groetjes,
> > Klaas
> >
>
> just scrolling through mails and did not look it up yet.
>
> But you likely mean tda8274a DVB-C, tda10023 and saa7146.
>
> Are we still here?
> http://www.linuxtv.org/pipermail/linux-dvb/2008-April/025634.html
>
> Please don't top post, you get more readers.
>
> Cheers,
> Hermann
>
>
> >
> > On Tue, Sep 30, 2008 at 11:18 AM, <jerremy at wordtgek.nl> wrote:
> > Hi Klaas,
> >
> > Perhaps its an idea to post this on the linux-dvb mailing
> > list, if anything
> > it keeps the subject alive.
> >
> > I've spent an hour or so playing with several of the
> > parameters of the
> > demodulator (the tda10023), mostly because this was suggest in
> > one of the
> > older posts about this issue. However none of my efforts gave
> > any desired
> > result and quickly got tired of unloading / reloading my
> > drivers (which
> > every so often required a hard reset as well).
> >
> > But if you find anything, that would be great ;)
> >
> > Gr. Jerremy
> >
> >
> > On Mon, 29 Sep 2008 11:35:03 +0200, "klaas de waal"
> > <klaas.de.waal at gmail.com> wrote:
> > > Hallo Jeremy,
> > > I have exactly the same problem with my C-1501 card: tuning
> > problems on
> > > 388
> > > MHz but OK on most other frequencies.
> > > It works OK with WIndowsXP on all frequencies including the
> > 388MHz, so
> > the
> > > hardware is OK and it must be a software issue.
> > > I have over the weekend put in a lot of printk for debugging
> > but have not
> > > found it yet.
> > > I will keep you updated.
> > >
> > > Groetjes,
> > > Klaas
> > >
> > >
> > > On Thu, Sep 11, 2008 at 5:50 PM, <jerremy at wordtgek.nl>
> > wrote:
> > >
> > >> Hi,
> > >>
> > >> This issue has come up at least once a bit more then a
> > month ago and is
> > >> still present in the current release of the V4L-DVB
> > drivers. The
> > >> Technotrend C-1501 drivers are unable to get a lock on
> > 388Mhz (and a
> > > couple
> > >> of other frequencies, like 682Mhz and 322Mhz, but I can
> > only test
> > > 388Mhz).
> > >>
> > >> The dmesg will mention an I2C timeout when this occurs, I'm
> > not sure if
> > > its
> > >> related (as it'll randomly give those timeouts when viewing
> > working
> > >> channels too).
> > >>
> > >> I have two seperate installs of Linux (Ubuntu 8.04 64-Bit
> > with 1
> > > received
> > >> and Ubuntu 8.04 32-Bit with 2 receivers) which both suffer
> > the same
> > >> inability to lock onto that frequency. So its unlikely to
> > be a hardware
> > >> problem, also the Windows drivers do not seem to have any
> > issues.
> > >>
> > >> Is anyone looking into this issue? If not, what would be
> > the place to
> > >> experiment?
> > >>
> > >> Gr,
> > >>
> > >> Jerremy Koot
> > >>
> > >>
>
Hello Herman,
Thanks for your post. I had not seen this message
http://www.linuxtv.org/pipermail/linux-dvb/2008-April/025634.html
before. Probably a lot of work has been done since because the card worked
quite OK, only on the 388MHz it failed on me.
As mentioned in an earlier post, first I got my tuner working by modifying
the frequency map table tda827x_dvbt to use a different setting at 388MHz. I
have now put in a frequency map table tda827x_dvbc for DVB-C tuners only.
This works OK for me and it should not modify the behaviour with other
non-DVB-C demodulators.
With the dvb-apps/util/zap utility I get a lock on all Ziggo (Dutch cable TV
provider) frequencies. With MythTV-0.21 I can receive all the channels that
I am entitled to.
Remaining (non-fatal) issues are:
Error message:
*saa7146 (0) saa7146_i2c_writeout [irq]: timed out waiting for end of xfer*
This message comes once in a while and it happens at random places, it
cannot be correlated to a single place in the tda827x code. It really seems
random. I have read though a lot of traces and when this error happens it
does a retry and the retry succeeds.
Error message:
*tda827x: tda827x_config not defined, cannot set LNA gain!*
This message comes on every tuning action. I think that the TT-C1501 board
does not have a separate LNA outside the tuner so this is not really an
error. It shoudl be possible to fill in a tda827x_config struct so that it
does not give this error message. I could change the code to achieve this
but I do not want to change everything at once.
Minor issue:
*Signal strength not the same across the band.*
On the frequencies I can receive (from 252MHz to 826,75MHz) there is quite a
lot of signal strength variation; on MythTV display ranging from 60+ to 80+
percent, on zap output from 90 to d0 or so. On a KNC-One DVB-C card (cu1216
with tda10023 plus saa7146) the signal strength is practically constant.
I have attached my version of the tda827x.c driver, both as complete source
and as a diff against the hg version of 10 october.
Groetjes,
Klaas
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