[Solved] OpenWrt on MT7621/MT7615N devices with 5GHz problems

From what I can see, development is mainly done using (master) snapshot builds or even in upstream code (e.g. linux kernel). You will have much higher success receiving responses from anybody who can professionally analyse the code, if you can reproduce these issues with master snapshot builds (downloadable from firmware selector) with a popular device that is actually supported by OpenWrt. Nobody wants to possibly (try to) fix a bug that potentially already has been fixed upstream or in the snapshot builds. I recon, "custom board" and "custom build" incite not very much interest in solving this, as no nobody knows what you have changed in the code.

Only DTS is custom.
Not other.

Word of caution:

Noticed sluggish response navigating LuCI with current Snapshot r22899 dated 2023-05-16.
Downloaded via Firmware Selector with following packages:
LuCI, irqbalance, adblock, luci-app-adblock

Initial login to LuCI took approximately 1 minute after pressing Login button.
Simply navigating one menu to another within LuCI took approximately 10 seconds.
Some changes/configurations within LuCI took approximately 1 minute for change.

With that said,
A lot better than the previous snapshot release, which took even longer time to login and navigate...

Since I download via Firmware Selector and add packages at the time,
Reverted back to snapshot r22599 dated 2023-04-19

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Has that fixed your 5GHz problems?

Due to sluggish reaction from router, testing never got that far.

Repeat of 2 previous snapshot releases.

Word of caution:

Noticed sluggish response navigating LuCI with current Snapshot r22909 dated 2023-05-18.
Downloaded via Firmware Selector with following packages:
LuCI, irqbalance, adblock, luci-app-adblock

Router: D-Link DIR-882 rev.A1
Since I download via Firmware Selector and add packages at the time,
Reverted back to snapshot r22599 dated 2023-04-19

Snapshot r22962 dated 2023-05-19
LuCI appears to be back to normal again.

Router: D-Link DIR-882 rev.A1

And the shocker: The 5 GHz WiFi appears to be working! :exploding_head:

Will test for a few days and edit original post, unless I hear screams of protest/anger from users.

No problems encountered with LuCI nor both WiFi
Ceased uptime/WiFi testing due to what appears to be an important commit added since.
Currently testing snapshot r23070 dated 2023-05-23.

Will test r23070 as long as possible unless another important commit interrupts testing again.

r23104 dated 2023-05-27: Webpages would load approx. 80% then take couple/several minutes to finish loading to 100%. Another Huawei android phone user complained of trouble connecting to 5 GHz.

Due to user complaints, reverted to r22995 dated 2023-05-21.


@FreeWRT In the lower left corner are the controls to follow a topic. Posting a reply useless to all others is not the preferred way to do so. What you want is "Watching", then you get notification for new replies.

EDIT: Firmware Selector appears to be working again. Tested fine for snapshot r23248 dated 2023-06-03

5 GHz WiFi functional but still slower than 2.4GHz.
Using sample web page,
2.4GHz: 7 secs
5 GHz: 45 secs

Reverted to r22995 dated 2023-05-21 due to better 5GHz WiFi
2.4GHz: 7 secs
5 GHz: 25 secs

With all that said,
I think I goofed. Should have kept a backup of snapshot r22962 dated 2023-05-19
If memory serves, the 5GHz performance was around 18 secs.


(I think you accidentally linked the post before.)

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Update: Gave the 23.05.0-rc1 a try.
Not surprisingly,
The 5 GHz WiFi performance similar to snapshots.

Sample web page time to open completely,
2.4GHz: 6 secs
5 GHz: 29 secs

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Could you please share the method you used to test this? I have an EA7500v2 and a DIR-882, and I would like to test them as well.

Slow speed over D-Link Dir 2640 OpenWrt 22.03.5


Hardware TP-Link XC220-G3v Firmware :1.2.0 0.8.0 v6062.0

Over 5Ghz 80Mhz Wifi - Download 146Mbps Upload 109Mbps

D-Link Dir 2640

OpenWrt 22.03.5

Over 5Ghz 80Mhz Wifi - Download 61.2Mbps Upload 25.2Mbps

with Qosify disabled - Download 96.6Mbps Upload 107Mbps

Packages build using firmware selector

luci-app-wireguard luci-app-pbr
stubby qosify
usbutils kmod-usb-storage-uas block-mount kmod-fs-ext4 kmod-usb-storage kmod-usb3 kmod-usb2 kmod-usb-core

Speedtest using https://speed.cloudflare.com/

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mt7621 devices will receive boost in 23.05.0-rc3 or 23.05 release. Wait for them or use 23.05-SNAPSHOT, wifi should work MUCH faster

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Never used snapshots, what should I know ?

With Release Candidate snapshots, nothing - except it's a "beta version" the next upcoming release.

For normal daily snapshots:

(First 2 web search results are these Wiki pages.)

I've installed last version. With 2.4GHz is a problem with r6220. The speed is very slow.... When I unchecked Force 40 MHz, the speed is almost 90 Mbps, but if is check, the max speed is about 40-50 Mbps Upload and 200 DW.


Update August 24, 2023:
re: OpenWrt 23.05.0-rc3
D-Link DIR-882 rev.A1

Both the 2.4 GHz and 5 GHz wireless appears to be working fine now.
Although 2.4GHz performance appears to have taken a bit of a hit but similar in performance to using a dedicated access point.

No abnormal delays in device handshake to router with 5 GHz WiFi.

Website connection performance was similar to that of a EnGenius EAP1250 access point = Good.

EDIT: Added router info.
EDIT: RC3 firmware used was not downloaded using Firmware Selector.
Using Firmware Selector with some packages resulted in being locked out of the router!

I doubt the accuracy of these web page opening speed tests. Have you cleared the browser cache/history before each test? Do 2.4G and 5G use the same encryption method? Channel electromagnetic interference situation? These key information always seem to be missing.

I found the reason why some mt7615 devices have poor performance. It's caused by the high TX power. mt76 driver doesn't handle the eeprom of external PA devices well, or vendors have their own modification. Anyway, in some external PA devices, the transmission power is incorrectly configured. This leads to PA working in the nonlinear amplification region.

How to workaround it:
Reduce your TX power, until you can get stable 780+ Mbps (866 is better) link speed under heavy load.

OR build source code with patch:

Subject: [PATCH] mt7615: fix exPA TX target power value
 mt7615/eeprom.c | 9 ---------
 mt7615/init.c   | 2 +-
 2 files changed, 1 insertion(+), 10 deletions(-)

--- a/mt7615/eeprom.c
+++ b/mt7615/eeprom.c
@@ -204,15 +204,6 @@ int mt7615_eeprom_get_target_power_index
 	if (chain_idx > 3)
 		return -EINVAL;
-	/* TSSI disabled */
-	if (mt7615_ext_pa_enabled(dev, chan->band)) {
-		if (chan->band == NL80211_BAND_2GHZ)
-		else
-	}
-	/* TSSI enabled */
 	if (chan->band == NL80211_BAND_2GHZ) {
 		index = MT_EE_TX0_2G_TARGET_POWER + chain_idx * 6;
 	} else {
--- a/mt7615/init.c
+++ b/mt7615/init.c
@@ -285,7 +285,7 @@ void mt7615_init_txpower(struct mt7615_d
 		delta += rate_val & MT_EE_RATE_POWER_MASK;
-	if (!is_mt7663(&dev->mt76) && mt7615_ext_pa_enabled(dev, band))
+	if (!is_mt7663(&dev->mt76) && !mt7615_ext_pa_enabled(dev, band))
 		target_chains = 1;
 		target_chains = n_chains;