Txpower for 5G on mt7610e limited to 11dbm (way under legal limit)

orangepizza · December 28, 2018, 5:44pm

iw phy shows it's txpower allowed up to 20dbm but It only goes up to 13dbm in openwrt, it's why weaker than same router on local stock firmware. TPlink archer C2 v1

Wiphy phy0
        max # scan SSIDs: 4
        max scan IEs length: 2243 bytes
        max # sched scan SSIDs: 0
        max # match sets: 0
        max # scan plans: 1
        max scan plan interval: -1
        max scan plan iterations: 0
        Retry short limit: 7
        Retry long limit: 4
        Coverage class: 0 (up to 0m)
        Available Antennas: TX 0x1 RX 0x1
        Supported interface modes:
                 * IBSS
                 * managed
                 * AP
                 * AP/VLAN
                 * monitor
                 * mesh point
        Band 1:
                Capabilities: 0x17e
                        HT20/HT40
                        SM Power Save disabled
                        RX Greenfield
                        RX HT20 SGI
                        RX HT40 SGI
                        RX STBC 1-stream
                        Max AMSDU length: 3839 bytes
                        No DSSS/CCK HT40
                Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
                Minimum RX AMPDU time spacing: 4 usec (0x05)
                HT TX/RX MCS rate indexes supported: 0-7
                Frequencies:
                        * 2412 MHz [1] (20.0 dBm)
                        * 2417 MHz [2] (20.0 dBm)
                        * 2422 MHz [3] (20.0 dBm)
                        * 2427 MHz [4] (20.0 dBm)
                        * 2432 MHz [5] (20.0 dBm)
                        * 2437 MHz [6] (20.0 dBm)
                        * 2442 MHz [7] (20.0 dBm)
                        * 2447 MHz [8] (20.0 dBm)
                        * 2452 MHz [9] (20.0 dBm)
                        * 2457 MHz [10] (20.0 dBm)
                        * 2462 MHz [11] (20.0 dBm)
                        * 2467 MHz [12] (20.0 dBm) (no IR)
                        * 2472 MHz [13] (20.0 dBm) (no IR)
                        * 2484 MHz [14] (20.0 dBm) (no IR)
        Band 2:
                Capabilities: 0x17e
                        HT20/HT40
                        SM Power Save disabled
                        RX Greenfield
                        RX HT20 SGI
                        RX HT40 SGI
                        RX STBC 1-stream
                        Max AMSDU length: 3839 bytes
                        No DSSS/CCK HT40
                Maximum RX AMPDU length 65535 bytes (exponent: 0x003)
                Minimum RX AMPDU time spacing: 4 usec (0x05)
                HT TX/RX MCS rate indexes supported: 0-7
                VHT Capabilities (0x01800120):
                        Max MPDU length: 3895
                        Supported Channel Width: neither 160 nor 80+80
                        short GI (80 MHz)
                VHT RX MCS set:
                        1 streams: MCS 0-7
                        2 streams: not supported
                        3 streams: not supported
                        4 streams: not supported
                        5 streams: not supported
                        6 streams: not supported
                        7 streams: not supported
                        8 streams: not supported
                VHT RX highest supported: 0 Mbps
                VHT TX MCS set:
                        1 streams: MCS 0-7
                        2 streams: not supported
                        3 streams: not supported
                        4 streams: not supported
                        5 streams: not supported
                        6 streams: not supported
                        7 streams: not supported
                        8 streams: not supported
                VHT TX highest supported: 0 Mbps
                Frequencies:
                        * 5180 MHz [36] (20.0 dBm)
                        * 5200 MHz [40] (20.0 dBm)
                        * 5220 MHz [44] (20.0 dBm)
                        * 5240 MHz [48] (20.0 dBm)
                        * 5260 MHz [52] (20.0 dBm) (no IR, radar detection)
                        * 5280 MHz [56] (20.0 dBm) (no IR, radar detection)
                        * 5300 MHz [60] (20.0 dBm) (no IR, radar detection)
                        * 5320 MHz [64] (20.0 dBm) (no IR, radar detection)
                        * 5500 MHz [100] (20.0 dBm) (no IR, radar detection)
                        * 5520 MHz [104] (20.0 dBm) (no IR, radar detection)
                        * 5540 MHz [108] (20.0 dBm) (no IR, radar detection)
                        * 5560 MHz [112] (20.0 dBm) (no IR, radar detection)
                        * 5580 MHz [116] (20.0 dBm) (no IR, radar detection)
                        * 5600 MHz [120] (20.0 dBm) (no IR, radar detection)
                        * 5620 MHz [124] (20.0 dBm) (no IR, radar detection)
                        * 5640 MHz [128] (20.0 dBm) (no IR, radar detection)
                        * 5660 MHz [132] (20.0 dBm) (no IR, radar detection)
                        * 5680 MHz [136] (20.0 dBm) (no IR, radar detection)
                        * 5700 MHz [140] (20.0 dBm) (no IR, radar detection)
                        * 5745 MHz [149] (20.0 dBm) (no IR)
                        * 5765 MHz [153] (20.0 dBm) (no IR)
                        * 5785 MHz [157] (20.0 dBm) (no IR)
                        * 5805 MHz [161] (20.0 dBm) (no IR)
                        * 5825 MHz [165] (20.0 dBm) (no IR)
        valid interface combinations:
                 * #{ IBSS } <= 1, #{ managed, AP, mesh point } <= 8,
                   total <= 8, #channels <= 1, STA/AP BI must match, radar detec                                                                                                                                                             t widths: { 20 MHz (no HT), 20 MHz, 40 MHz, 80 MHz }

        HT Capability overrides:
                 * MCS: ff ff ff ff ff ff ff ff ff ff
                 * maximum A-MSDU length
                 * supported channel width
                 * short GI for 40 MHz
                 * max A-MPDU length exponent
                 * min MPDU start spacing
        Device supports VHT-IBSS.

tiagogaspar8 · January 13, 2019, 3:27am

Same problem here!
I really hope someone can help us.
Also may be worth mentioning that in the system logs I get a error message from hostapd saying " ACS: Survey is missing noise floor" and some more errors.

Sparks · January 13, 2019, 5:38am

This is usually down to the drivers available

What do this show
lsmod | grep 802

orangepizza · January 13, 2019, 5:45am

root@OpenWrt:~# lsmod | grep 802
cfg80211              231808  4 rt2x00lib,mt76x02_lib,mt76,mac80211
compat                  6519  4 rt2800soc,rt2800pci,mac80211,cfg80211
mac80211              452353  8 mt2800lib,mt76x0e,mt76x0_common,rt2x00soc,rt2x00pci,rt2x00lib,mt76x02_lib,mt76

while both say mac80211 on luci, only 5GHz (mt7610e) has low txpower problem.

Sparks · January 13, 2019, 6:00am

i see you already found this:

As i see it, two options:

Wait for improvements in this driver
There might be some other alternate driver available, but thats a long shot. Youd likely have to compile it manually

orangepizza · January 13, 2019, 11:18am

Actually, I think a found alternative driver: https://github.com/Nossiac/mtk-openwrt-feeds
will try if it works. but doew menuconfig allow not including default drivers?

Sparks · January 13, 2019, 7:58pm

No theres definitely a way to do it, but i cant remember off the top of my head and the wiki isnt loading for me right now.

Do a search for the articles on how to add a package to openwrt. In your case may need to alter slightly since its a kernel module. Follow the steps and compile it locally . Copy the resulting .ko files over to openwrt. The hard part then will be how to remove the current module(s) eithwr rmmod or modprobe -r modulename , then modprobe your new modules.

Failing that, if the old driver initializing the radios puts in in funny state when it boots, should be a file to blacklist them from being loaded. Last resort would be to compile a custom image and flash it (although others might actually say to just try this first )

suppenkasper0815 · May 15, 2019, 2:59pm

Hi,

it's really annoying that this topic still continues...

Is anyone able to conclude the situation and why it's not already implemented into the standard-kernel? There are already patch-solutions.

Look here: https://www.kickstarter.com/projects/1327597961/better-support-for-mt7620a-n-in-openwrt-lede

Is anyone able to implement this to our kmod-mt76x0e package oder kmod-mt76?

At the moment I tried MT76x0e devices which is not able to transmit more than 2m without any wall 5GHz. Tested on Archer C20i, Archer C2, Newifi Mini alias Leonvo Y1. I think also the Xiomi MI 3 Router on Openwrt is a mess on 5 GHz. They use also the same MT-Chipset-Mess.

Maybe these are also good addresses to find the needed information for patching:

suppenkasper0815 · January 11, 2021, 4:50pm

Are there any news?

Especially @orangepizza

How did you solve this issue for Archer C2? I can just transmit 9dBm with new Openwrt 19.07.5

suppenkasper0815 · August 12, 2021, 12:32pm

Hey guys,

sorry for coming up again but problem is still present in all of my Archer C2 devices. Also with Openwrt 21.02 rc4. So I think there is still in general a problem with power limited to 10 dBm or 11dBm and also that wifi is still not stable @5GHz

Did someone get any further @Sparks or @orangepizza?

Sparks · August 12, 2021, 7:48pm

I do not own his device so can’t help directly.

Have you set the country code correctly. Some drivers default to minimum if not.

That said, I get the sense this device might be aging a little by now. If you decide to upgrade, do some research for one that does not have many issues mentioned here on the forum - sometimes issues take a long time (or never ) to get resolved. Best of luck

danghuy1994 · August 13, 2021, 9:12am

I got issue on my device as well. My is TPLink RE200 use MT7610. iwinfo report tx power of 10dBm on channel 44 and 13dBm on channel 149. Seem like missing activating external amplifier ...

danghuy1994 · August 13, 2021, 9:17am

I googled and there is a patch fix tx power issue: mt7610e external frontend patch · Issue #286 · openwrt/mt76 (github.com)

But I checked on master it seems haven't applied (or I am wrong): https://github.com/openwrt/mt76/blob/bbebea7d6dc64313132226adc3f7369d36e9359d/mt76x0/phy.c#L439

suppenkasper0815 · August 20, 2021, 9:28pm

hey @danghuy1994 I would love if it would finally find a way into masters and into every punished deivce with MT7610 chipsets!

I have also an Archer C20i which also operates with MT7610(e), I guess it is the same hardware as the Archer C2.

Even when the hardware is aging the big advantage is the very low power consumption! I messured it and it is betwenn 2,5W and 4W from this device with 1GbE and MT7610 active!

So that is really impressive for me and for a lot of usages it is enough to have a 1x1 device with 433 Mbit/s. Also there are USB-Adapters with that MT7610 chipsets which are still a pain in the ass under linux systems. Hopefully it will make it into mainline kernel very soon and I would love if someone would help me to bring patch into my own builds. I have also already compiled own images on my device. But I am still struggeling howto bring in patches that should work.

If it will work, I would also offer my images to other users.

Would love if someone helps me with compiling.

Cheers Alex

suppenkasper0815 · August 30, 2021, 8:20pm

Update : I also noticed a toggling behavior if you wanna use the mt7610e in access point mode. It's just working sometimes as client on that chipset. Is anyone having success to activate the amplifier and use it as an ap?