Bug 263015 - iwlwifi: huge drop in driver performance on 13.1-RC1
Summary: iwlwifi: huge drop in driver performance on 13.1-RC1
Status: Open
Alias: None
Product: Base System
Classification: Unclassified
Component: wireless (show other bugs)
Version: 13.1-RELEASE
Hardware: amd64 Any
: --- Affects Only Me
Assignee: Bjoern A. Zeeb
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2022-04-02 20:21 UTC by Patricio Villar
Modified: 2022-05-19 23:40 UTC (History)
3 users (show)

See Also:


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Description Patricio Villar 2022-04-02 20:21:03 UTC
First of all, many thanks to Bjoern Zeeb and the FreeBSD Foundation for providing initial support for all these new Intel wireless cards.

I was very happy to see iwlwifi driver finally working fast (around 17 mbps download speed) and stable on 13.1-BETA3.

Since upgrading to 13.1-RC1, I was pleased to see the driver auto-loading through devmatch, but unfortunately the download speed did drastically decrease to about 2 mbps.

I don't know if this is a known issue or only affects my card model (Intel Wireless-AC 9560). Anyway, this is the relevant pciconf output:

class=0x028000 rev=0x00 hdr=0x00 vendor=0x8086 device=0x02f0 subvendor=0x8086 subdevice=0x0034

vendor     = 'Intel Corporation'
device     = 'Comet Lake PCH-LP CNVi WiFi'
class      = network
Comment 1 Bjoern A. Zeeb freebsd_committer 2022-04-02 21:49:16 UTC
Hi,

have you checked how you are associated?
What does ifconfig -v wlan0 (or the appropriate interface name) say?

And how did you measure "download speed"?


There are other users who have reported that they cannot associate at all with the 9560 CNVi, so seems you are more blessed if that works.  So let me ask you, is it more stable now than it was on BETA1 or have you not seen any issues?
Comment 2 Patricio Villar 2022-04-03 02:33:00 UTC
(In reply to Bjoern A. Zeeb from comment #1)
Well, on 13.1-RC1 it actually fails to associate several times, but eventually does connect (probably thanks to wpa_gui retrying over and over again or something like that). Then a manual restart of dhclient gets me an IP address and I'm able to browse the web.

I measured the download speed with fast.com. Maybe it's not the most precise way to do it but the difference is quite noticeable. It's now always between 1.5 - 2.4 mbps, while on 13.1-BETA3 it was in the range between 16 - 18 mbps.

As for 13.1-BETA1, I didn't really run it. I started testing 13.1 at BETA3, so that's my only point of comparison. And BETA3 seemed to work pretty well...


Output of "ifconfig -v wlan0":

wlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        ether 8c:c6:81:e7:90:14
        inet 192.168.1.128 netmask 0xffffff00 broadcast 192.168.1.255
        groups: wlan
        ssid "PAVR 5G" channel 149 (5745 MHz 11a) bssid cc:ed:dc:80:85:79
        regdomain FCC country US anywhere -ecm authmode WPA2/802.11i -wps
        -tsn privacy ON deftxkey UNDEF
        AES-CCM 2:128-bit
        powersavemode OFF powersavesleep 100 txpower 23 txpowmax 50.0 -dotd
        rtsthreshold 2346 fragthreshold 2346 bmiss 7
        11a     ucast NONE    mgmt  6 Mb/s mcast  6 Mb/s maxretry 6
        11b     ucast NONE    mgmt  1 Mb/s mcast  1 Mb/s maxretry 6
        11g     ucast NONE    mgmt  1 Mb/s mcast  1 Mb/s maxretry 6
        scanvalid 60 -bgscan bgscanintvl 300 bgscanidle 250
        roam:11a     rssi    7dBm rate 12 Mb/s
        roam:11b     rssi    7dBm rate  1 Mb/s
        roam:11g     rssi    7dBm rate  5 Mb/s
        -pureg protmode CTS -ht -htcompat -ampdu ampdulimit 64k
        ampdudensity 4 -amsdu -shortgi htprotmode RTSCTS -puren -smps -rifs
        -stbc -ldpc -uapsd -vht -vht40 -vht80 -vht160 -vht80p80 wme -burst
        -dwds roaming MANUAL bintval 100
        AC_BE cwmin  4 cwmax 10 aifs  3 txopLimit   0 -acm ack
              cwmin  4 cwmax 10 aifs  3 txopLimit   0 -acm
        AC_BK cwmin  4 cwmax 10 aifs  7 txopLimit   0 -acm ack
              cwmin  4 cwmax 10 aifs  7 txopLimit   0 -acm
        AC_VI cwmin  3 cwmax  4 aifs  2 txopLimit  94 -acm ack
              cwmin  3 cwmax  4 aifs  2 txopLimit  94 -acm
        AC_VO cwmin  2 cwmax  3 aifs  2 txopLimit  47 -acm ack
              cwmin  2 cwmax  3 aifs  2 txopLimit  47 -acm
        parent interface: iwlwifi0
        media: IEEE 802.11 Wireless Ethernet OFDM/36Mbps mode 11a
        status: associated
        nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>



Relevant bits of /etc/rc.conf:

wlans_iwlwifi0="wlan0"
ifconfig_wlan0="WPA DHCP"
background_dhclient_wlan0="YES"
defaultroute_delay="0"
defaultroute_carrier_delay="0"
Comment 3 Bjoern A. Zeeb freebsd_committer 2022-05-16 18:31:52 UTC
Has this (despite the code not changing in the release branch) changes in any way?

Also I wonder if you are measuring both download and upload speed and if one or both were affected?
Comment 4 Patricio Villar 2022-05-19 23:40:45 UTC
(In reply to Bjoern A. Zeeb from comment #3)
Well, I just updated to FreeBSD 13.1-RELEASE and gave iwlwifi another try. I couldn't even associate at all, as it kept scanning without success...
Anyway, my previous tests were only about download speed, so not sure if upload speed was affected as well.

BTW, in the meantime I've been successfully using net/wifibox as a workaround and am very happy with it, but still I look forward to use iwlwifi in the near future and wish you good luck!