[LEDE-DEV] ath9k sta/wpa2 fails on 4.9

[Tim Harvey]

On Thu, Mar 30, 2017 at 1:56 PM, Tim Harvey <tharvey at gateworks.com> wrote:
> I've found that ath9k sta mode with wpa2 crypto is failing on lede
> master with a 4.9 kernel but if I move back to the 4.4 kernel it
> works. I'm testing this on the imx6 target.
>
> I'm running wpa_supplican't manually for testing. Here's 4.9:
> root at LEDE:/# cat << EOF > /var/run/wpa
>> country=US
>> network={
>>         scan_ssid=1
>>         ssid="testssid"
>>         key_mgmt=WPA-PSK
>>         psk="testpass"
>>         proto=RSN
>> }
>> EOF
> wpa_supplicant -i wlan0 -c /var/ruroot at LEDE:/# wpa_supplicant -i wlan0
> -c /var/run/wpa -D nl80211
> Successfully initialized wpa_supplicant
> wpa_supplicant -i wlan0 -c /var/ruroot at LEDE:/# wpa_supplicant -i wlan0
> -c /var/run/wpa -D nl80211
> Successfully initialized wpa_supplicant
> wlan0: SME: Trying to authenticat[  164.723884] wlan0: authenticate
> with 02:1a:11:fc:d1:e3 (SSID='testssid' freq=2437 MHz)
> [  157.912650] wlan0: send auth to 02:1a:11:fc:d1:e3 (try 1/3)
> [  159.112796] wlan0: send auth to 02:1a:11:fc:d1:e3 (try 2/3)
> [  159.992785] wlan0: send auth to 02:1a:11:fc:d1:e3 (try 3/3)
> [  160.962781] wlan0: authentication with 02:1a:11:fc:d1:e3 timed out
>
> wlan0: SME: Trying to authenticat[  164.723884] wlan0: authenticate
> with 02:1a:11:fc:d1:e3
> e with 02:1a:11:fc:d1:e3 (SSID='testssid' freq=2437 MHz)
> [  164.742628] wlan0: send auth to 02:1a:11:fc:d1:e3 (try 1/3)
> [  166.072802] wlan0: send auth to 02:1a:11:fc:d1:e3 (try 2/3)
> [  166.952787] wlan0: send auth to 02:1a:11:fc:d1:e3 (try 3/3)
> [  167.992781] wlan0: authentication with 02:1a:11:fc:d1:e3 timed out
>
>
> and on 4.4 everything works ok:
> root at LEDE:/# cat << EOF > /var/run/wpa
>> country=US
>> network={
>>         scan_ssid=1
>>         ssid="testssid"
>>         key_mgmt=WPA-PSK
>>         psk="testpass"
>>         proto=RSN
>> }
>> EOF
> wpa_supplicant -i wlan0 -c /var/run/wproot at LEDE:/# wpa_supplicant -i
> wlan0 -c /var/run/wpa -D nl80211
> Successfully initialized wpa_supplicant
> [   91.081202] IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
> wlan0: SME: Trying to authenticat[   94.077000] wlan0: authenticate
> with 02:1a:11:fc:d1:e3
> e with 02:1a:11:fc:d1:e3 (SSID='testssid' freq=2437 MHz)
> [   94.095541] wlan0: send auth to 02:1a:11:fc:d1:e3 (try 1/3)
> [   94.102998] wlan0: authenticated
> wlan0: Trying to associate with 02:1a:11:fc:d1:e3 (SSID='testssid[
> 94.110957] wlan0: associate with 02:1a:11:fc:d1:e3 (try 1/3)
> ' freq=2437 MHz)
> [   94.122579] wlan0: RX AssocResp from 02:1a:11:fc:d1:e3 (capab=0x411
> status=0 aid=2)
> [   94.130449] wlan0: associated
> [   94.133533] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
> wlan0: Associated with 02:1a:11:fc:d1:e3
> wlan0: CTRL-EVENT-SUBNET-STATUS-UPDATE status=0
> wlan0: WPA: Key negotiation completed with 02:1a:11:fc:d1:e3 [PTK=CCMP GTK=CCMP]
> wlan0: CTRL-EVENT-CONNECTED - Connection to 02:1a:11:fc:d1:e3
> completed [id=0 id_str=]
>
> I've seen the same issue on mainline as discussed on linux-wireless
> here: https://www.spinics.net/lists/linux-wireless/msg160645.html
>
> Is there perhaps a kernel config I'm missing in 4.9 that could be causing this?
>
> Regards,
>
> Tim

This turns out to be because the 4.9 kernel requires MSI to be enabled
for IMX6 and the ath9k card and/or driver doesn't support MSI.
Therefore interrupts were not being processed. I'll need to work up a
patch that disables MSI for IMX6 if we can't figure out how to make
the IMX6 raise the legacy interrupts.

Tim