Belkin RT3200/Linksys E8450 WiFi AX discussion

For Developers
3161

Considering a Belkin RT3200 and had a couple of questions.

From the device OpenWRT wiki page, there is documentation on how to "Change the default CPU governor" Is there any downside to making this change and if so may I ask why it is not the default?

Regarding "Enabling Wireless Ethernet Dispatch (WED) HW acceleration for Wireless clients," while I fully understand there is no way to specifically quantify the improvement in speed if enabled but is the improvement like 10-25% or something greater?

Any way for these options to be made user selectable in the firmware GUI in a future build?

TIA

3162

Wireless Ethernet Dispatch (WED) HW acceleration for Wireless clients makes wireless downlink (download) from the router to the clients bypass the CPU for lower CPU load. But not for uplink (upload) from the clients on this router.

3163

Thanks for the additional info on WED although I'm not sure it really addresses my questions. The wiki states, "reduce CPU loads/increase routing throughput" so is the difference significant or just theoretical?

3164

That limitation seems to be changing:

commit 4e1a6ee903369cec5de1eb435ce614d4ff77beb0
Author: Felix Fietkau <nbd@nbd.name>
Date:   Mon Nov 21 20:46:46 2022 +0100

    kernel: add WED rx support for mediatek
    
    This is required for rx flow offloading on mt76 with MT7986 and MT7915
3165

Yes, but only for newer SoCs. The MT7622 found in RT3200/E8450 only supports WED TX.

3166

That is because RT3200 have the md7915e version?

[    7.256920] mt7915e 0000:01:00.0: assign IRQ: got 146
3167

No. The MT7622 SoC simply doesn't support WED RX. Only newer SoC (MT7986, ...) does.
MT7915 would be fine for RX and TX WED, but not with this MT7622 SoC.

3 Likes
3168

@dan3 Do you get proper transfers with collectd/luci-app-statistics? For me none of the transfers (except maybe for eth0) show proper values - for example puling ~150Mbps from the internet on lan3 port (linux host) I don't see this traffic neither on wan nor lan3 port graphs.. It shows for ex.13,5kbps...

3169

I guess it could be because of HW acceleration you could try to turn it off and see.

3170

I have not had much luck with tracking bandwidth. I think I broke it by installing both luci-app-statistics and luci-app-nlbwmon. I believe polling Tx/Rx stats resets the values to zero. With two services polling the same stats, and saving their results in separate rrd files, neither service has good data. SMH.

3171

I try to activate wed as described on router openwrt page https://openwrt.org/toh/linksys/e8450#enable_wed but this file /etc/modules.conf doesn't exist, any help?

3172

I observed the same on 22.03.
My APs with WED are all on SNAPSHOT.

3173

Create the file

3174

nope, it doesn't work that way, after creating this file i still have this response:
cat /sys/module/mt7915e/parameters/wed_enable
N
BTW I'm on OpenWrt 22.03-SNAPSHOT r19862-615dbec223

Any other ideas?

3175

I wrote that section of the wiki based on my experience with it. Did you reboot after following the wiki? Post the output of cat /etc/modules.conf

3176

Yes
cat /etc/modules.conf options mt7915e wed_enable=Y

3177

and then check: cat /sys/kernel/debug/ppe0/bin
I belive Wiki needs to be updated.
Kr.

3 Likes
3178

thx it did the trick, it seems wiki is outdated
I have updated it

1 Like
3179

Once WED is enabled, you should see all wifi related connections here:

cat /sys/kernel/debug/mtk_ppe/entries

@lukjod could you also update wiki regarding verifying step ?

Still pointing to:

cat /sys/kernel/debug/ppe0/bind
1 Like
3180

done now its cat /sys/kernel/debug/mtk_ppe/entries