Problems with kernel parameter coherent_pool

5 10608

Actually I am trying to build a TV streaming server using tvheadend. I already have one running on a Raspberry Pi but I want to get it up and running on a Banana Pi because of the possibility to record TV programs on a SATA hard drive and to stream over a 1Gbit/s network. The Banana Pi seems to be very suitable for that.

For receiving satalite TV I connected a Technisat Skystar USB2 HD via USB. The driver for this device is integrated in the actual Linux kernel. (simply add the line "dvb-usb-technisat-usb2" to the file /etc/modules and copy the approbriate firmware file to /lib/firmware.

During boot the device is recognized but I get the message:

ERROR: 256 KiB atomic DMA coherent pool is too small!
Please increase it with coherent_pool= kernel parameter!

What (and how) can I do????

Thanks in advance....
Post Last Edited by nnn2 at 2014-7-24 13:20

Open your uEnv.txt and add coherent_pool=8M (or more? google what is needed) to the bootargs line

Reply 2# nnn2

Thank you nnn2,

With your info I got the problem solved. With "coherent_pool=8M" the driver for the Technisat crashed. I decreased it to "coherent_pool=2M" and it works. The file uEnv.txt is an the first FAT partition of the SD card. You have to mount this partition to get access to the file uEnv.txt.

Now tvheadend is running on my Banana Pi. When I got some expierence with tvheadend I will share it in this Forum.

So long...

Reply 3# IjonTichy

This tvheadend thing is running fine on my Banana Pi. It streams HDTV in my privat home LAN to other PCs, mobile phones and tablets. Downloading recorded films from TV is really fast in comparison to my Raspbery Pi. The next step will be to integrate the Banana Pi, the SatTV usb box, the harddisk and an USB hub into a case to get in compliance with my wife :-)

The power consumption of this box is very low (in comparison with my first solution using an old pc)

I'm really interested in that solution. I had my banana pi since 2 months now and use it with android. But i'd like to test your solution.
Can i have some advice to install it ?
Do you have the link for the installer of Linux kernel ?
Does it contain the driver for Aston Diva HD Premium (satelite decoder) ?
Thank's a lot for your help

IjonTichy replied at Jul 25, 2014 04:06
Reply 2# nnn2

Thank you nnn2,

Hello, where is the uEnv.txt?

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