Missing modules in stock kernel?

pchristy · 07-27-2024, 10:24 AM

Slackwareaarch64-current running on Pi400:

For some time now, I haven't been able to get DVB working with the stock kernel. It works fine with the Pi-fork. Finally got round to investigating today, and it appears that the dvb-frontends module folder is missing. dvb-core is there, but not dvb-frontends. It is present in the Pi-fork kernel, and also in the stock x86_64 current kernel.

It should be under /lib/modules/6.9.X-armv8/kernel/drivers/media/

I think this happened a while back, because it certainly was working on the stock kernel a year or so ago.

--
Pete

glorsplitz · 07-27-2024, 05:25 PM

looking at /usr/src/linux/.config, there's so many dvb whatevers

Quote:

a/kernel_armv8-6.9.12-aarch64-1.txz: Upgraded.
Added a number of DVB Frontends. Thanks to pchristy for the suggestion. I
don't know which ones you need, but here's a start! ;-)

did drmozes get what you were looking for?

pchristy · 07-28-2024, 01:51 AM

Close, but no cigar!

The one I was after is the cxd2880, which is used by the official Pi-HAT tv tuner. For some reason, it seems to live in its own sub-folder in dvb-frontends. I have no idea why. The attached screenshot is from Stuart's Pi-fork kernel (6.9.5). I wonder if its something unique to the Pi kernel? Strange, as its a Sony chip (I believe), and I've had it working in the past, but not for some time now.

Another reason for sticking with the Pi-fork kernel for the present, at least.

Anyway, adding the front-ends directory has at least got my usb-dvb dongle to work with the stock kernel, so that's good enough.

Thanks Stuart and glorsplitz!

--
Pete

drmozes · 07-29-2024, 03:45 AM

These will be in the next Kernel, once we upgrade to 6.10.

Code:

root@kitt:/devel/armedslack/slackwareaarch64-current/source/k/configs# grep CXD28 config-armv8
CONFIG_CXD2880_SPI_DRV=m
CONFIG_DVB_CXD2820R=m
CONFIG_DVB_CXD2841ER=m

pchristy · 07-29-2024, 06:25 AM

Cheers, Stuart!

One word of warning - there are two cxd2880 modules: cxd2880 and cxd2880_spi. The Pi TV-hat module seems to need both. I *think* the _spi module is just an enabler for the base cxd2880 modules, but don't quote me on that. All I know is that when I run the Pi-fork kernel and watch TV, it uses both cxd modules + dvb_core.

I had a look at the Slackware x86_64 kernel source code (didn't have the pi running at the time) and both modules are available in that, so I don't think its something the Pi folk have added. Will have a look at the Pi source later today...

--
Pete