Date: Tue, 8 Apr 2014 07:08:59 +0000 (UTC) From: Adrian Chadd <adrian@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r264254 - head/sys/dev/ath Message-ID: <201404080708.s3878xTb068239@svn.freebsd.org>
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Author: adrian Date: Tue Apr 8 07:08:59 2014 New Revision: 264254 URL: http://svnweb.freebsd.org/changeset/base/264254 Log: Correct the actual definition of ath_tx_tid_filt_comp_single() to match how it's used. This is another bug that led to aggregate traffic hanging because the BAW tracking stopped being accurate. In this instance, a filtered frame that exceeded retries would return a non-error, which would mean the caller would never remove it from the BAW. But it wouldn't be added to the filtered list, so it would be lost forever. There'd thus be a hole in the BAW that would never get transmitted and this leads to a traffic hang. Tested: * Routerstation Pro, AR9220 AP Modified: head/sys/dev/ath/if_ath_tx.c Modified: head/sys/dev/ath/if_ath_tx.c ============================================================================== --- head/sys/dev/ath/if_ath_tx.c Tue Apr 8 07:01:27 2014 (r264253) +++ head/sys/dev/ath/if_ath_tx.c Tue Apr 8 07:08:59 2014 (r264254) @@ -3388,10 +3388,13 @@ ath_tx_tid_filt_comp_complete(struct ath /* * Called when a single (aggregate or otherwise) frame is completed. * - * Returns 1 if the buffer could be added to the filtered list - * (cloned or otherwise), 0 if the buffer couldn't be added to the + * Returns 0 if the buffer could be added to the filtered list + * (cloned or otherwise), 1 if the buffer couldn't be added to the * filtered list (failed clone; expired retry) and the caller should * free it and handle it like a failure (eg by sending a BAR.) + * + * since the buffer may be cloned, bf must be not touched after this + * if the return value is 0. */ static int ath_tx_tid_filt_comp_single(struct ath_softc *sc, struct ath_tid *tid, @@ -3412,7 +3415,8 @@ ath_tx_tid_filt_comp_single(struct ath_s __func__, bf, bf->bf_state.bfs_seqno); - return (0); + retval = 1; /* error */ + goto finish; } /* @@ -3432,11 +3436,12 @@ ath_tx_tid_filt_comp_single(struct ath_s DPRINTF(sc, ATH_DEBUG_SW_TX_FILT, "%s: busy buffer couldn't be cloned (%p)!\n", __func__, bf); - retval = 1; + retval = 1; /* error */ } else { ath_tx_tid_filt_comp_buf(sc, tid, nbf); - retval = 0; + retval = 0; /* ok */ } +finish: ath_tx_tid_filt_comp_complete(sc, tid); return (retval);
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