[Solved] DVB Adapter TBS6985 does not work in CentOS 7

[andrewju]

Hi All,

I just upgraded my main machine from CentOS 6.5 to CentOS 7. In fact, it was not an upgrade. It's a clean install of CentOS 7. So there are no leftowers from the previous system, for sure.

I have trouble getting my TBS6985 DVB card to work. It worked fine on CentOS 6.5, but so far I have no luck in CentOS 7.

I downloaded and compiled the latest driver from TBS web site (tbs-linux-drivers_v140819.zip). The driver compiles with some warnings - but I'm not sure if these are important. The output of 'make' is here:
http://pastebin.com/raw.php?i=u8y0jx5Q

Then 'make install' runs as usual (as far as I could tell):
http://pastebin.com/raw.php?i=64yMV6S1

But I do not see the DVB adapter in /dev/dvb even after a reboot.

The dmesg output is here:
http://pastebin.com/raw.php?i=dtGnJWyh

and lspci output is here:
http://pastebin.com/raw.php?i=sTdtpxap


My system is:
# uname -a
Linux vertex 3.10.0-123.8.1.el7.x86_64 #1 SMP Mon Sep 22 19:06:58 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux



I would appreciate any help in tracking and fixing this issue...



EDIT:

I think this may be the issue:

# modprobe tbs6985fe
modprobe: ERROR: could not insert 'tbs6985fe': Required key not available

But I'm really not sure what to do with it...

Some more info:

# rpm -q kernel | sort
kernel-3.10.0-123.8.1.el7.x86_64
kernel-3.10.0-123.el7.x86_64
# find /lib/modules -type f -name tbs6985fe.ko
/lib/modules/3.10.0-123.8.1.el7.x86_64/kernel/drivers/media/dvb/frontends/tbs6985fe.ko
/lib/modules/3.10.0-123.8.1.el7.x86_64/updates/media/tbs6985fe.ko
# modinfo $(find /lib/modules -type f -name tbs6985fe.ko)
filename: /lib/modules/3.10.0-123.8.1.el7.x86_64/kernel/drivers/media/dvb/frontends/tbs6985fe.ko
license: TurboSight Proprietary: http://www.tbsdtv.com
author: Konstantin Dimitrov <kosio.dimitrov@gmail.com>
description: TurboSight TBS 6985 DVBS/S2 frontend driver module
depends: i2c-core
vermagic: 3.10.0-123.8.1.el7.x86_64 SMP mod_unload modversions
filename: /lib/modules/3.10.0-123.8.1.el7.x86_64/updates/media/tbs6985fe.ko
license: TurboSight Proprietary: http://www.tbsdtv.com
author: Konstantin Dimitrov <kosio.dimitrov@gmail.com>
description: TurboSight TBS 6985 DVBS/S2 frontend driver module
depends: i2c-core
vermagic: 3.10.0-123.8.1.el7.x86_64 SMP mod_unload modversions



Hmmm:

# diff /lib/modules/3.10.0-123.8.1.el7.x86_64/updates/media/tbs6985fe.ko /lib/modules/3.10.0-123.8.1.el7.x86_64/kernel/drivers/media/dvb/frontends/tbs6985fe.ko
Binary files /lib/modules/3.10.0-123.8.1.el7.x86_64/updates/media/tbs6985fe.ko and /lib/modules/3.10.0-123.8.1.el7.x86_64/kernel/drivers/media/dvb/frontends/tbs6985fe.ko differ
# ls -l /lib/modules/3.10.0-123.8.1.el7.x86_64/kernel/drivers/media/dvb/frontends/tbs6985fe.ko
-rw-r--r-- 1 root root 21544 Oct 22 22:06 /lib/modules/3.10.0-123.8.1.el7.x86_64/kernel/drivers/media/dvb/frontends/tbs6985fe.ko
# ls -l /lib/modules/3.10.0-123.8.1.el7.x86_64/updates/media/tbs6985fe.ko
-rw-r--r-- 1 root root 396840 Oct 22 17:44 /lib/modules/3.10.0-123.8.1.el7.x86_64/updates/media/tbs6985fe.ko

[andrewju]

The more I think of it, the more I believe it is a module signing issue.

Code: Select all

# modprobe -v tbs6985fe
insmod /lib/modules/3.10.0-123.8.1.el7.x86_64/updates/media/tbs6985fe.ko
modprobe: ERROR: could not insert 'tbs6985fe': Required key not available

Kinda strange, since I expected it will just work when compiled on a system where it is meant to be installed.

While googling for similar issues, I came to an advise to set 'enforcemodulesig=0' in grub. I didn't try that yet, since grub2 is a bit out of my understanding. On the opposite side, some people reported 'enforcemodulesig' didn't solve their issue, so I'm not even sure whether I need to dig grub further in order to solve this.

Another advice I found is to disable 'SecureBoot'. I do use EFI (or UEFI?) boot, but I'm not sure if it enables SecureBoot automatically. And I also don't yet know how to disable it (if it is enabled)...

[andrewju]

Update:

It appeared that I was not able to load any custom-compiled kernel modules. The modprobe always failed with a "Required key not available" error.


Passing 'enforcemodulesig=0' to kernel at bootup did not solve the issue. So I googled some more and found out that SecureBoot can be changed from the motherboard BIOS (or UEFI to be precise). A nice article on this is here.

After switching SecureBoot 'OS Type' parameter in UEFI Setup from 'Windows' (default) to 'Other OS' the system booted up and loaded all the needed custom modules.

Looks like technology advanced beyond what I expected. I never thought some BIOS setting will affect the system in THIS way. Well, at least I learned something new today!