i think i need to revive this very old thread.
i ran into some problems with my new dvb box after the old one gave up permanently (probably due to worn out flash) and then learned a few things.

apparently i need to use PLP=1 for the dvb-t2 channels to get a lock.
if i use my dvb box and uses plp=0 as is the default it never locks on to the t2 frequencies and never finds any of the dvb-t2 channels (= all the hd channels)

so as was discussed earlier i think my issue with the new version of ct2-4650 is related to plp.

when this thread was going last year i ran into issues i could not solve and then gave up since it wasn't too important to have the ct2-4650 working.
but maybe it is time to give this another try.

also last year i had issues loading the media build modules due to an extra kernel module that was built that i just had to delete (didn't know it back then)

so, two main questions:
how is plp supposed to work? is the drivers supposed to auto detect this?
if so, how do i convince the drivers to use plp=1 when i use for example w_scan ?

and secondly, if drivers is supposed to auto detect plp, it clearly doesn't happen for me. since this works on windows, is it possible that the windows driver is using a newer firmware for the si6168-b40 than 4.0.25? (latest one i found on: http://palosaari.fi/linux/v4l-dvb/firmware/Si2168/Si2168-B40/)
any advice on how to check or capture what the windows driver uses?


On 2016-06-06 13:30, Torbjorn Jansson wrote:
FYI i still get "Exec format error" while modprobing cx23885 with media_build from today.

any chance of having this fixed so i can test the mediabuild code with my dvbsky card?

On 2016-03-03 23:03, Torbjorn Jansson wrote:
found something, modprobe results in the following dmesg message:

frame_vector: exports duplicate symbol frame_vector_create (owned by

every time i do a modprobe of cx23885
what does this mean?

On 2016-03-03 22:58, Torbjorn Jansson wrote:
i'm having a bit of a problem testing the changed firmware on my t980c

complied the code from media_tree and i get the usb card to work with
those modules but for some reason modprobe of cx23885 results in:
# modprobe cx23885
modprobe: ERROR: could not insert 'cx23885': Exec format error

all the other modules work just fine, i'm not sure what i'm doing wrong.

On 2016-03-03 19:22, Torbjorn Jansson wrote:
i was about to ask how to easiest see what firmware i was running
without rebooting when i realized i already have it in this mail
thread ;)

all of the firmware i'm running is the ones that came from dvbsky
directly in this file:

i suspect i should go thru all of the firmware files i use since if one
is bad the other ones is probably also bad.

i assume i also should also check: dvb-tuner-si2158-a20-01.fw
what version is a good one? i have found 2 different files:

the one i current usefrom dvbsky, also same as OpenELEC fw repo uses
with md5sum:
8e98d25d6219e235b519a3c47dbfa856  dvb-tuner-si2158-a20-01.fw

and then i found another one at
0cba7ce61c1411cbe7f22c0746e24e33  dvb-tuner-si2158-a20-01.fw
this file is a bit smaller.

i will retest with the new firmware you suggested and see what happens.

On 2016-03-03 12:02, Olli Salonen wrote:
Hi Jurgen, Torbjörn,

I've noticed that there is currently a small confusion about the
firmware versions for the Si2168-A20 demodulator. This is used in the
older versions of DVBSky T680C (TechnoTrend CT2-4650 CI) and DVBSky
T980C (TechnoTrend CT2-4500 CI).

The version 2.0.5 does not support PLP handling and seems to work very
badly with the Linux driver - at least for me. Version 2.0.35 on the
other hand seems to find all DVB-T/T2 channels for me just fine with
both dvbv5-scan and w_scan (devices used for this test: TechnoTrend
CT2-4650 CI and TechnoTrend CT2-4500 CI new version).

Versions used:
dvbv5-scan version 1.7.0
w_scan version 20150111 (compiled for DVB API 5.10)

So if you are running these Si2168-A20 based devices, make sure you've
got the firmware 2.0.35 that can be downloaded for example here:


On 20 February 2016 at 19:20, Jurgen Kramer <gtmkra...@xs4all.nl>

On Sat, 2016-02-20 at 16:57 +0100, Torbjorn Jansson wrote:
i have tested your patch with my dvbsky dvb-t2 card.
testing was done by compiling a custom kernel with your patch
test was done against fedora 22 4.3.4-200 kernel

with the patch included the CI slot is found.
so there is some progress for sure
[   10.189408] cx25840 11-0044: loaded v4l-cx23885-avcore-01.fw
(16382 bytes)
[   10.206683] cx23885_dvb_register() allocating 1 frontend(s)
[   10.207968] cx23885[0]: cx23885 based dvb card
[   10.224306] i2c i2c-10: Added multiplexed i2c bus 12
[   10.225633] si2168 10-0064: Silicon Labs Si2168 successfully
[   10.243310] si2157 12-0060: Silicon Labs Si2147/2148/2157/2158
successfully attached
[   10.244560] DVB: registering new adapter (cx23885[0])
[   10.245807] cx23885 0000:07:00.0: DVB: registering adapter 0
0 (Silicon Labs Si2168)...
[   10.417402] sp2 9-0040: CIMaX SP2 successfully attached
[   10.447120] DVBSky T980C MAC address: 00:17:42:54:09:85
[   10.448844] cx23885_dev_checkrevision() Hardware revision = 0xa5
[   10.450550] cx23885[0]/0: found at 0000:07:00.0, rev: 4, irq: 19,
latency: 0, mmio: 0xf6e00000

later when tuning:

[   67.728109] si2168 10-0064: found a 'Silicon Labs Si2168-A20'
[   67.802203] si2168 10-0064: downloading firmware from file
[   68.968336] si2168 10-0064: firmware version: 2.0.5
[   68.977071] si2157 12-0060: found a 'Silicon Labs Si2158-A20'
[   69.961057] si2157 12-0060: downloading firmware from file
[   70.969094] si2157 12-0060: firmware version: 2.1.9

but using dvbv5-scan to scan it doesn't find any channel.
all i get is this:
Scanning frequency #1 770000000
         (0x00) Signal= -114.00dBm
Scanning frequency #2 754000000
         (0x00) Signal= -27.00dBm C/N= 32.50dB
Scanning frequency #3 546000000
         (0x00) Signal= -25.00dBm C/N= 33.75dB
Scanning frequency #4 650000000
         (0x00) Signal= -18.00dBm C/N= 36.00dB
Scanning frequency #5 522000000
         (0x00) Signal= -28.00dBm C/N= 33.00dB

so something else is broken too.

I have been using the patches for a few days. So far everything works
great (using MythTV). Scanning with dvbv5_scan does indeed not work
(never did for me). w_scan works though.

Can these patches please be included in the stable kernels ?


On 2016-02-16 21:20, Olli Salonen wrote:
Hi all,

Found the issue and submitted a patch.

The I2C buses for T980C/T2-4500CI were crossed when CI registration
was moved to its own function.


On 31 January 2016 at 10:55, Torbjorn Jansson
<torbjorn.jans...@mbox200.swipnet.se> wrote:
this ci problem is the reason i decided to buy the CT2-4650 usb
based device
but the 4650 was a slightly newer revision needing a patch i
and also this 4650 device does not have auto switching between
dvb-t and t2
like the dvbsky card have, so i also need an updated version of

my long term wish is to not have to patch things or build custom
kernels or
so anything done to improve the dvbsky card or the 4650 is much

On 2016-01-28 20:42, Olli Salonen wrote:

Hi Jürgen & Mauro,

I did bisect this and it seems this rather big patch broke it:

2b0aac3011bc7a9db27791bed4978554263ef079 is the first bad
commit 2b0aac3011bc7a9db27791bed4978554263ef079
Author: Mauro Carvalho Chehab <mche...@osg.samsung.com>
Date:   Tue Dec 23 13:48:07 2014 -0200

       [media] cx23885: move CI/MAC registration to a separate

       As reported by smatch:
Function too hairy.  Giving up.

       This is indeed a too complex function, with lots of stuff
       Breaking this into two functions makes it a little bit
less hairy.

       Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung

It's getting a bit late, so I'll call it a day now and have a
look at
the patch to see what goes wrong there.


On 28 January 2016 at 20:57, Jurgen Kramer <gtmkra...@xs4all.nl

Hi Olli,

On Thu, 2016-01-28 at 19:26 +0200, Olli Salonen wrote:

Hi Jürgen,

Did you get anywhere with this?

I have a clone of your card and was just starting to look
at this
issue. Kernel 3.19 seems to work ok, but 4.3 not. Did you
have any
time to try to pinpoint this more?

No, unfortunately not. I have spend a few hours adding
printk's but it
did not get me any closer what causes the issue. This really
investigation from someone who is more familiar with linux

Last thing I tried was the latest (semi open) drivers from
dvbsky on a
4.3 kernel. Here the CI and CAM registered successfully.



On 12 September 2015 at 10:02, Jurgen Kramer <gtmkramer@xs4

On Fri, 2015-09-11 at 22:01 +0200, Torbjorn Jansson

On 2015-08-23 19:50, Jurgen Kramer wrote:

On Sun, 2015-07-12 at 12:38 +0200, Jurgen Kramer

I have been running a couple of DVBSky T980C's with
CIs with
using an older kernel (3.17.8) with media-build and
added patches
from the mailing list.

I thought lets try a current 4.0 kernel to see if I
no longer
need to be
running a custom kernel. Everything works just fine
the CAM
module. I am seeing these:

[  456.574969] dvb_ca adapter 0: Invalid PC card
inserted :(
[  456.626943] dvb_ca adapter 1: Invalid PC card
inserted :(
[  456.666932] dvb_ca adapter 2: Invalid PC card
inserted :(

The normal 'CAM detected and initialised' messages
to do show
up with

I am not sure what changed in the recent kernels,
what is
needed to
debug this?


Retest. I've isolated one T980C on another PC with
4.1.5, still the same 'Invalid PC card inserted :('
Even after installed today's media_build from git no

Any hints where to start looking would be

cimax2.c|h do not seem to have changed. There are
changes to


did you get it to work?

No, it needs a thorough debug session. So far no one
seems able to

i got a dvbsky T980C too for dvb-t2 reception and so
far the only
drivers that have worked at all is the ones from dvbsky

i was very happy when i noticed that recent kernels
have support
for it
built in but unfortunately only the modules and
firmware loads
but then
nothing actually works.
i use mythtv and it complains a lot about the signal,
femon also
produces lots of errors.

so i had to switch back to kernel 4.0.4 with mediabuild

if there were any other dvb-t2 card with ci support
that had
drivers i would change right away.

one problem i have with the mediabuilt from dvbsky is
that at
boot the
cam never works and i have to first tune a channel,
then remove
reinstert the cam to get it to work.
without that nothing works.

and finally a problem i ran into when i tried
mediabuilt from
fedora uses kernel modules with .ko.xz extension so
when you
install the
mediabuilt modulels you get one modulename.ko and one

before a make install from mediabuild overwrote the
any advice on how to handle this now?

To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to