Date: Tue, 15 May 2012 04:43:47 GMT From: Adrian Chadd <adrian@FreeBSD.org> To: freebsd-gnats-submit@FreeBSD.org Subject: kern/167902: [ath] TX block-ack window holes Message-ID: <201205150443.q4F4hlEU039488@red.freebsd.org> Resent-Message-ID: <201205150450.q4F4o2IZ054721@freefall.freebsd.org>
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>Number: 167902 >Category: kern >Synopsis: [ath] TX block-ack window holes >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: Tue May 15 04:50:02 UTC 2012 >Closed-Date: >Last-Modified: >Originator: Adrian Chadd >Release: 9.0-STABLE i386, with -HEAD net80211/ath >Organization: >Environment: FreeBSD marilyn 9.0-STABLE FreeBSD 9.0-STABLE #0 r235422M: Sun May 13 20:57:56 PDT 2012 adrian@marilyn:/home/adrian/work/freebsd/stable/9/sys/i386/compile/MARILYN-9-STABLE i386 >Description: When doing traffic tests w/ 11n debugging on, I've noticed that the RX side is reporting holes in the TX BA space. Some example logging is: wlan1: [00:03:7f:0b:62:88] discard MPDU frame, BA win <310:373> (0 frames) rxseq 309 tid 0 (retransmit) wlan1: [00:03:7f:0b:62:88] discard MPDU frame, BA win <542:605> (0 frames) rxseq 541 tid 0 (retransmit) wlan1: [00:03:7f:0b:62:88] discard MPDU frame, BA win <831:894> (0 frames) rxseq 830 tid 0 (retransmit) wlan1: [00:03:7f:0b:62:88] discard MPDU frame, BA win <886:949> (0 frames) rxseq 885 tid 0 (retransmit) wlan1: [00:03:7f:0b:62:88] discard MPDU frame, BA win <909:972> (0 frames) rxseq 908 tid 0 (retransmit) --- these wlan1: [00:03:7f:0b:62:88] move BA win <1372:1435> (62 frames) rxseq 1436 tid 0 wlan1: [00:03:7f:0b:62:88] move BA win <1373:1436> (63 frames) rxseq 1437 tid 0 --- these wlan1: [00:03:7f:0b:62:88] discard MPDU frame, BA win <1447:1510> (0 frames) rxseq 1446 tid 0 (retransmit) wlan1: [00:03:7f:0b:62:88] discard MPDU frame, BA win <1561:1624> (0 frames) rxseq 1560 tid 0 (retransmit) wlan1: [00:03:7f:0b:62:88] discard MPDU frame, BA win <1660:1723> (0 frames) rxseq 1659 tid 0 (retransmit) wlan1: [00:03:7f:0b:62:88] discard MPDU frame, BA win <2054:2117> (0 frames) rxseq 2053 tid 0 (retransmit) wlan1: [00:03:7f:0b:62:88] discard MPDU frame, BA win <2107:2170> (0 frames) rxseq 2106 tid 0 (retransmit) wlan1: [00:03:7f:0b:62:88] discard MPDU frame, BA win <2122:2185> (0 frames) rxseq 2121 tid 0 (retransmit) wlan1: [00:03:7f:0b:62:88] discard MPDU frame, BA win <2890:2953> (0 frames) rxseq 2889 tid 0 (retransmit) A pcap of the live traffic showed that some frames inside the BA weren't ever ACKed. I figured that the send side was thus not being properly notified that the transmission failed. I then added some code to ath_tx_processq() to print out ts_status if it's 0 but not HAL_TXERR_XRETRY. It turns out that I was seeing HAL_TXERR_FILT errors. The filtered frames were just being treated as incorrect completions, hence the above BA window slide. >How-To-Repeat: * enable 11n * on the receiving side - wlandebug -i wlanX +11n * .. do some traffic. >Fix: The TX completion routines need to handle non-XRETRY errors. >Release-Note: >Audit-Trail: >Unformatted:
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