wcn6855 - stuck in 20Mhz on rx, but full 80mhz on tx

wcn6855 - stuck in 20Mhz on rx, but full 80mhz on tx

[Yaroslav Isakov]

Hello! I found that my new laptop, Thinkpad T14 Gen 4 AMD, cannot use
80Mhz for rx - even though AP supports 80mhz, and tx shows full 80Mhz.
I reported it as https://bugzilla.kernel.org/show_bug.cgi?id=218246,
with all the details, but, there is no comments in it, so, sending it
for visibility.

Re: wcn6855 - stuck in 20Mhz on rx, but full 80mhz on tx

[Kalle Valo]

Yaroslav Isakov <yaroslav.isakov@gmail.com> writes:

> Hello! I found that my new laptop, Thinkpad T14 Gen 4 AMD, cannot use
> 80Mhz for rx - even though AP supports 80mhz, and tx shows full 80Mhz.
> I reported it as https://bugzilla.kernel.org/show_bug.cgi?id=218246,
> with all the details, but, there is no comments in it, so, sending it
> for visibility.

A team in Qualcomm said that they are looking at this. Do you know if
this happens also with the stock firmware or is this openwrt specific?

-- 
https://patchwork.kernel.org/project/linux-wireless/list/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

Re: wcn6855 - stuck in 20Mhz on rx, but full 80mhz on tx

[Yaroslav Isakov]

Hello, Kalle!
Thank you for answer, unfortunately, I would prefer to stay on
openwrt, until it will be ruled out, that issue is not with my laptop.
I have this router for many years, and it was always on openwrt, and I
did not have such issue with my older laptop, on iwlwifi driver, and
with any of my phones, with this exact router.

I've tried different firmwares and drivers on the router -
kmod-ath10k, kmod-ath10k-ct (currently used, most stable),
ath10k-firmware-qca988x-ct-full-htt (currently used, most stable),
ath10k-firmware-qca988x-ct, ath10k-firmware-qca988x - no difference at
all (except stability of MCS)

ср, 13 дек. 2023 г. в 06:16, Kalle Valo <kvalo@kernel.org>:
>
> Yaroslav Isakov <yaroslav.isakov@gmail.com> writes:
>
> > Hello! I found that my new laptop, Thinkpad T14 Gen 4 AMD, cannot use
> > 80Mhz for rx - even though AP supports 80mhz, and tx shows full 80Mhz.
> > I reported it as https://bugzilla.kernel.org/show_bug.cgi?id=218246,
> > with all the details, but, there is no comments in it, so, sending it
> > for visibility.
>
> A team in Qualcomm said that they are looking at this. Do you know if
> this happens also with the stock firmware or is this openwrt specific?
>
> --
> https://patchwork.kernel.org/project/linux-wireless/list/
>
> https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

Re: wcn6855 - stuck in 20Mhz on rx, but full 80mhz on tx

[Kalle Valo]

Yaroslav Isakov <yaroslav.isakov@gmail.com> writes:

> Thank you for answer, unfortunately, I would prefer to stay on
> openwrt, until it will be ruled out, that issue is not with my laptop.

I'm not asking you to switch your firmware, I was merely asking if you
had tested this with a stock firmware or not. The more datapoints we
have the better chances there are to fix this.

BTW, please don't top post:

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches#do_not_top_post_and_edit_your_quotes

-- 
https://patchwork.kernel.org/project/linux-wireless/list/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

Re: wcn6855 - stuck in 20Mhz on rx, but full 80mhz on tx

[Yaroslav Isakov]

чт, 14 дек. 2023 г. в 16:11, Kalle Valo <kvalo@kernel.org>:
>
> Yaroslav Isakov <yaroslav.isakov@gmail.com> writes:
>
> > Thank you for answer, unfortunately, I would prefer to stay on
> > openwrt, until it will be ruled out, that issue is not with my laptop.
>
> I'm not asking you to switch your firmware, I was merely asking if you
> had tested this with a stock firmware or not. The more datapoints we
> have the better chances there are to fix this.

Unfortunately, I did not test it with stock firmware.

>
> BTW, please don't top post:
>
> https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches#do_not_top_post_and_edit_your_quotes

Sorry, my bad - this is what Gmail does by default. Thank you for pointing out!

>
> --
> https://patchwork.kernel.org/project/linux-wireless/list/
>
> https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

Re: wcn6855 - stuck in 20Mhz on rx, but full 80mhz on tx

[Yaroslav Isakov]

чт, 14 дек. 2023 г. в 21:29, Yaroslav Isakov <yaroslav.isakov@gmail.com>:
>
> чт, 14 дек. 2023 г. в 16:11, Kalle Valo <kvalo@kernel.org>:
> >
> > Yaroslav Isakov <yaroslav.isakov@gmail.com> writes:
> >
> > > Thank you for answer, unfortunately, I would prefer to stay on
> > > openwrt, until it will be ruled out, that issue is not with my laptop.
> >
> > I'm not asking you to switch your firmware, I was merely asking if you
> > had tested this with a stock firmware or not. The more datapoints we
> > have the better chances there are to fix this.
>
> Unfortunately, I did not test it with stock firmware.
>
> >
> > BTW, please don't top post:
> >
> > https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches#do_not_top_post_and_edit_your_quotes
>
> Sorry, my bad - this is what Gmail does by default. Thank you for pointing out!
>
> >
> > --
> > https://patchwork.kernel.org/project/linux-wireless/list/
> >
> > https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

Hello!

I debug this issue further, a bit - it seems that it might be a
display issue. I enabled debug for ath11k driver, and it showed me
ath11k_pci 0000:02:00.0: mac peer <peer-address> phymode 11ac-vht80

Also, when testing with iperf3, it showed me 300 mbit/s, and it was
limited by CPU on router (ksoftirqd was 99%), which is much higher
than 150 mbit showed in iw dev wlan0 link

I also tried to use 802.11n on router (HT40), and with such setting,
iw dev wlan0 link showed me 300 mbit, with 40 mhz channel width
(although iperf3 showed 200 mbit) - so, it seems that this issue is
appearing only on VHT.

My phone (Pixel 7) was able to provide me HE, with which I did not
have such issue. I cannot downgrade it to VHT, to test, if the issue
will be reproduced with phone-provided WiFi, too (after disabling
802.11ac in wpa_supplicant, it rejected to find the network)

P.S. I updated firmware for laptop wifi, from
https://github.com/kvalo/ath11k-firmware/tree/master/WCN6855/hw2.0,
but, it did not change anything.

Re: wcn6855 - stuck in 20Mhz on rx, but full 80mhz on tx

[Yaroslav Isakov]

Hello! I managed to get another router, Asus TUF-AX6000 (with openwrt,
too), and on this one, there is the same problem with rx
bitrate/channel width display, in AC mode.

When I'm switching to AX, there is no display problem (it shows
HE-VCS, even 160 Mhz width), but, the speed of download (measured via
iperf3 -c -R on laptop) is the same as in AC mode, around 150 mbit,
while upload speed is around 800 mbit. I tried 80 Mhz, I tried
different firmware versions, available on
https://github.com/kvalo/ath11k-firmware/tree/master/WCN6855/hw2.0,
but the issue is still the same. I tried to disable power_save,
without any results. It seems that the issue is with WCN6855, not with
router, as my phone managed to reach ~800 mbit download (using iperf3,
too), from the same router. What can I provide, to debug it further?

ср, 27 дек. 2023 г. в 10:32, Yaroslav Isakov <yaroslav.isakov@gmail.com>:
>
> чт, 14 дек. 2023 г. в 21:29, Yaroslav Isakov <yaroslav.isakov@gmail.com>:
> >
> > чт, 14 дек. 2023 г. в 16:11, Kalle Valo <kvalo@kernel.org>:
> > >
> > > Yaroslav Isakov <yaroslav.isakov@gmail.com> writes:
> > >
> > > > Thank you for answer, unfortunately, I would prefer to stay on
> > > > openwrt, until it will be ruled out, that issue is not with my laptop.
> > >
> > > I'm not asking you to switch your firmware, I was merely asking if you
> > > had tested this with a stock firmware or not. The more datapoints we
> > > have the better chances there are to fix this.
> >
> > Unfortunately, I did not test it with stock firmware.
> >
> > >
> > > BTW, please don't top post:
> > >
> > > https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches#do_not_top_post_and_edit_your_quotes
> >
> > Sorry, my bad - this is what Gmail does by default. Thank you for pointing out!
> >
> > >
> > > --
> > > https://patchwork.kernel.org/project/linux-wireless/list/
> > >
> > > https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
>
> Hello!
>
> I debug this issue further, a bit - it seems that it might be a
> display issue. I enabled debug for ath11k driver, and it showed me
> ath11k_pci 0000:02:00.0: mac peer <peer-address> phymode 11ac-vht80
>
> Also, when testing with iperf3, it showed me 300 mbit/s, and it was
> limited by CPU on router (ksoftirqd was 99%), which is much higher
> than 150 mbit showed in iw dev wlan0 link
>
> I also tried to use 802.11n on router (HT40), and with such setting,
> iw dev wlan0 link showed me 300 mbit, with 40 mhz channel width
> (although iperf3 showed 200 mbit) - so, it seems that this issue is
> appearing only on VHT.
>
> My phone (Pixel 7) was able to provide me HE, with which I did not
> have such issue. I cannot downgrade it to VHT, to test, if the issue
> will be reproduced with phone-provided WiFi, too (after disabling
> 802.11ac in wpa_supplicant, it rejected to find the network)
>
> P.S. I updated firmware for laptop wifi, from
> https://github.com/kvalo/ath11k-firmware/tree/master/WCN6855/hw2.0,
> but, it did not change anything.

Re: wcn6855 - stuck in 20Mhz on rx, but full 80mhz on tx

[Yaroslav Isakov]

пт, 29 дек. 2023 г. в 17:46, Yaroslav Isakov <yaroslav.isakov@gmail.com>:
>
> Hello! I managed to get another router, Asus TUF-AX6000 (with openwrt,
> too), and on this one, there is the same problem with rx
> bitrate/channel width display, in AC mode.

Looks like the issue was with GCMP-256 cipher. I changed all ciphers
to the AC ones (CCMP+BIP), and now upload and download speeds are
around 1gigabit. I'll try different ones, to see if there is issue
with only one, or with all modern ciphers.

Re: wcn6855 - stuck in 20Mhz on rx, but full 80mhz on tx

[Ben Greear]

On 12/29/23 9:06 AM, Yaroslav Isakov wrote:
> пт, 29 дек. 2023 г. в 17:46, Yaroslav Isakov <yaroslav.isakov@gmail.com>:
>>
>> Hello! I managed to get another router, Asus TUF-AX6000 (with openwrt,
>> too), and on this one, there is the same problem with rx
>> bitrate/channel width display, in AC mode.
> 
> Looks like the issue was with GCMP-256 cipher. I changed all ciphers
> to the AC ones (CCMP+BIP), and now upload and download speeds are
> around 1gigabit. I'll try different ones, to see if there is issue
> with only one, or with all modern ciphers.
> 

The linux kernel's software decrypt performs poorly, partially due to
the crypto folks' refusal to add in the aesni crypto accelerator logic.

Thanks,
Ben

-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com

Re: wcn6855 - stuck in 20Mhz on rx, but full 80mhz on tx

[Yaroslav Isakov]

пт, 29 дек. 2023 г. в 18:20, Ben Greear <greearb@candelatech.com>:
>
> On 12/29/23 9:06 AM, Yaroslav Isakov wrote:
> > пт, 29 дек. 2023 г. в 17:46, Yaroslav Isakov <yaroslav.isakov@gmail.com>:
> >>
> >> Hello! I managed to get another router, Asus TUF-AX6000 (with openwrt,
> >> too), and on this one, there is the same problem with rx
> >> bitrate/channel width display, in AC mode.
> >
> > Looks like the issue was with GCMP-256 cipher. I changed all ciphers
> > to the AC ones (CCMP+BIP), and now upload and download speeds are
> > around 1gigabit. I'll try different ones, to see if there is issue
> > with only one, or with all modern ciphers.
> >
>
> The linux kernel's software decrypt performs poorly, partially due to
> the crypto folks' refusal to add in the aesni crypto accelerator logic.
>
> Thanks,
> Ben
>
> --
> Ben Greear <greearb@candelatech.com>
> Candela Technologies Inc  http://www.candelatech.com
>
I thought, all such ciphers are implemented in hardware? I tried to
load ath11k with crypto_mode=1, to see, if it will make any difference
- and yes, it made - download speed becomes even lower.

I've tried different pairwise_cipher options, and the only one giving
me expected speed was CCMP (not even CCMP-256). mgmt_group_cipher
makes no difference, so, I can set BIP-GMAC-256, and if
pairwise_cipher is CCMP, I'm getting 1+ gbit.