misc/169362: [ath] AR5416: radar pulse PHY errors sometimes include the CRC Error bit set as well as the PHY errors

[Adrian Chadd]

>Number:         169362
>Category:       misc
>Synopsis:       [ath] AR5416: radar pulse PHY errors sometimes include the CRC Error bit set as well as the PHY errors
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sun Jun 24 04:20:10 UTC 2012
>Closed-Date:
>Last-Modified:
>Originator:     Adrian Chadd
>Release:        9.0-STABLE i386, with -HEAD net80211/ath
>Organization:
>Environment:
>Description:

Under repetitive pulse generation (from a USRP N200), the AR5416 starts generating PHY errors with the CRC error bit set.

Here's an example RX descriptor dump with the error. The payload still contains the pulse length; it's just the "CRC" bit that's throwing things off.


Jun 23 21:02:24 marilyn kernel: R[ 0] (DS.V:0xe9d6ca60 DS.P:0x205a60) L:00205ac0 D:2e4f3800 !
Jun 23 21:02:24 marilyn kernel: 2a9bea20 00000800 00323431 00000001
Jun 23 21:02:24 marilyn kernel: 566a76ed 00000100 3722211f 80808080 80808080 80808080 00000515
Jun 23 21:02:24 marilyn kernel: R[ 0] (DS.V:0xe9d6cac0 DS.P:0x205ac0) L:00205b20 D:14ea1800
Jun 23 21:02:24 marilyn kernel: 2a9bea20 00000800 00000000 00000000
Jun 23 21:02:24 marilyn kernel: 00000000 00000000 00000000 00000000 00000000 00000000 00000000
Jun 23 21:02:24 marilyn kernel: R[ 0] (DS.V:0xe9d6cac0 DS.P:0x205ac0) L:00205b20 D:14ea1800 !
Jun 23 21:02:24 marilyn kernel: 2a9bea20 00000800 00323431 00000001
Jun 23 21:02:24 marilyn kernel: 566a7ebe 00000100 3720211e 80808080 80808080 80808080 00000515
Jun 23 21:02:24 marilyn kernel: R[ 0] (DS.V:0xe9d6cb20 DS.P:0x205b20) L:00205b80 D:06e38000
Jun 23 21:02:24 marilyn kernel: 2a9beae0 00000800 00000000 00000000
Jun 23 21:02:24 marilyn kernel: 00000000 00000000 00000000 00000000 00000000 00000000 00000000
Jun 23 21:02:24 marilyn kernel: R[ 0] (DS.V:0xe9d6cb20 DS.P:0x205b20) L:00205b80 D:06e38000 !
Jun 23 21:02:24 marilyn kernel: 2a9beae0 00000800 00313431 00000001
Jun 23 21:02:24 marilyn kernel: 566a82a5 00000100 371f211e 80808080 80808080 80808080 00000515
Jun 23 21:02:24 marilyn kernel: R[ 0] (DS.V:0xe9d6cb80 DS.P:0x205b80) L:00205be0 D:13a14000
Jun 23 21:02:24 marilyn kernel: 2a9beb40 00000800 00000000 00000000
Jun 23 21:02:24 marilyn kernel: 00000000 00000000 00000000 00000000 00000000 00000000 00000000
Jun 23 21:02:24 marilyn kernel: R[ 0] (DS.V:0xe9d6cb80 DS.P:0x205b80) L:00205be0 D:13a14000 !
Jun 23 21:02:24 marilyn kernel: 2a9beb40 00000800 00323431 00000001
Jun 23 21:02:24 marilyn kernel: 566a868e 00000100 371f201e 80808080 80808080 80808080 00000515
Jun 23 21:02:24 marilyn kernel: R[ 0] (DS.V:0xe9d6cbe0 DS.P:0x205be0) L:00205c40 D:2a0c7000
Jun 23 21:02:24 marilyn kernel: 2a9beba0 00000800 00000000 00000000
Jun 23 21:02:24 marilyn kernel: 00000000 00000000 00000000 00000000 00000000 00000000 00000000
Jun 23 21:02:24 marilyn kernel: R[ 0] (DS.V:0xe9d6cbe0 DS.P:0x205be0) L:00205c40 D:2a0c7000 !
Jun 23 21:02:24 marilyn kernel: 2a9beba0 00000800 00323432 00000001
Jun 23 21:02:24 marilyn kernel: 566a8a76 00000100 38282320 80808080 80808080 80808080 00000515
Jun 23 21:02:24 marilyn kernel: R[ 0] (DS.V:0xe9d6cc40 DS.P:0x205c40) L:00205ca0 D:2aae6800
Jun 23 21:02:24 marilyn kernel: 2a9bec00 00000800 00000000 00000000
Jun 23 21:02:24 marilyn kernel: 00000000 00000000 00000000 00000000 00000000 00000000 00000000
Jun 23 21:02:24 marilyn kernel: R[ 0] (DS.V:0xe9d6cc40 DS.P:0x205c40) L:00205ca0 D:2aae6800 !
Jun 23 21:02:24 marilyn kernel: 2a9bec00 00000800 00323430 00000001
Jun 23 21:02:24 marilyn kernel: 566abadd 00000100 3723231f 80808080 80808080 80808080 00000515

>How-To-Repeat:
* Enable radar detection on the AR5416
* Snoop radar frames
* Watch radar frames under load eventually start also triggering CRC errors
>Fix:
Likely just a SW WAR.

>Release-Note:
>Audit-Trail:
>Unformatted: