Tx power with mt76 driver

Hardware Questions and Recommendations
1

Hi guys,

I am using a BananaPi R64 with MT7615 extension module and noticed the driver of OpenWrt 22.03.3 only allows 6 dBm Tx power. This is a bit too weak for my house. I know that some other WiFi modules have drivers which can go much further than 6 dBm. I would need at least 15 or 20 dBm. Would it be possible to do something which enables higher Tx power limits in the driver?

Thank you,
Oebbler

2

Did you verify that it's actually that low? I see the same, but the signal still looks good compared to other APs I suspect it's a display error only. Maybe related to amplifier calculations?

3

Check the settings as shown here Low tx power mt7610e

4

Yes, it is that low. When I leave the room where the router is, I have a very weak signal strength. With my old AP I didn't have this problem.

Unfortunately patching my mtd2 partition was unsuccessful and lead to a bootloop. Are there any other things I can do?

5

Please note that I encouraged you to get some information from the card and not patching the partition :wink:

6

This is because this board is a development board that doesn't have a built-in EEPROM. Without the EEPROM, there is no configuration data for the board and it is limited to its boot power of 6dBm.

There is a rather extensive thread on this issue on the Banana Pi forum. To summarize, I was able to patch the mt76 driver to allow it to load the EEPROM from a file, and then use the EEPROM settings from another mt7615 card which allows for power up to 24dBm.

If you want, the patch is available here. When building OpenWrt, if you are in the openwrt folder, you can get the patch and store it to the right place by:

# mt76 eeprom.c patch to allow eeprom loading from files
mkdir package/kernel/mt76/patches
wget https://va1der.ca/~public/openwrt/patches/mt76/999-mt76_eeprom_file_220302.diff -O package/kernel/mt76/patches/999-mt76_eeprom_file_220302.diff

EDIT: Incidentally, what revision of board is your R64?

3 Likes
7

Thank you for your replies!

It sounds a bit complicated to compile OpenWrt by myself because I have to reapply the patch in order to compiling every time OpenWrt gets an update. In my opinion this is not practical enough. Would there be another solution for this problem, i.e. change the boot parameters of the mt76 driver with a script on every boot?

My BananaPi is revision 1.2 and my MT7615 extension board is revision 1.0.