svn commit: r237626 - head/sys/dev/ath/ath_hal/ar5416
Adrian Chadd
adrian at FreeBSD.org
Wed Jun 27 05:23:34 UTC 2012
Author: adrian
Date: Wed Jun 27 05:23:33 2012
New Revision: 237626
URL: http://svn.freebsd.org/changeset/base/237626
Log:
Fix a subtle corner case surrounding the handling of OFDM restart along
with AMPDU aggregate delimiters.
If there's an OFDM restart during an aggregate, the hardware ACKs
the previous frame, but communicates the RXed frame to the hardware
as having had CRC delimiter error + OFDM_RESTART phy error.
The frame however didn't have a CRC error and since the hardware ACKed
the aggregate to the sender, it thinks the frame was received.
Since I have no idea how often this occurs in the real world, add a
debug statement so trigger whenever this occurs. I'd appreciate an
email if someone finds this particular situation is triggered.
Modified:
head/sys/dev/ath/ath_hal/ar5416/ar5416_recv.c
Modified: head/sys/dev/ath/ath_hal/ar5416/ar5416_recv.c
==============================================================================
--- head/sys/dev/ath/ath_hal/ar5416/ar5416_recv.c Wed Jun 27 04:39:30 2012 (r237625)
+++ head/sys/dev/ath/ath_hal/ar5416/ar5416_recv.c Wed Jun 27 05:23:33 2012 (r237626)
@@ -240,11 +240,25 @@ ar5416ProcRxDesc(struct ath_hal *ah, str
if (ads->ds_rxstatus8 & AR_PHYErr) {
u_int phyerr;
- rs->rs_status |= HAL_RXERR_PHY;
+ /*
+ * Packets with OFDM_RESTART on post delimiter are CRC OK and
+ * usable and MAC ACKs them.
+ * To avoid packet from being lost, we remove the PHY Err flag
+ * so that driver layer does not drop them.
+ */
phyerr = MS(ads->ds_rxstatus8, AR_PHYErrCode);
- rs->rs_phyerr = phyerr;
- }
+ if ((phyerr == HAL_PHYERR_OFDM_RESTART) &&
+ (ads->ds_rxstatus8 & AR_PostDelimCRCErr)) {
+ ath_hal_printf(ah,
+ "%s: OFDM_RESTART on post-delim CRC error\n",
+ __func__);
+ rs->rs_phyerr = 0;
+ } else {
+ rs->rs_status |= HAL_RXERR_PHY;
+ rs->rs_phyerr = phyerr;
+ }
+ }
if (ads->ds_rxstatus8 & AR_CRCErr)
rs->rs_status |= HAL_RXERR_CRC;
else if (ads->ds_rxstatus8 & AR_DecryptCRCErr)
More information about the svn-src-all
mailing list