svn commit: r242880 - head/sys/dev/ath

[Adrian Chadd]

Author: adrian
Date: Sat Nov 10 22:37:06 2012
New Revision: 242880
URL: http://svnweb.freebsd.org/changeset/base/242880

Log:
  Correct some rather weird and broken behaviour observed when doing
  actual traffic with an AR9380/AR9382/AR9485.
  
  The sample rate control stats would show impossibly large numbers for
  "successful packets transmitted."  The number was a tad under 2^^64-1.
  So after a bit of digging, I found that the sample rate control code
  was making 'tries' turn into a negative number.. and this was because
  ts_longretry was too small.
  
  The hardware returns "ts_longretry" at the current rate selection,
  not overall for that TX descriptor.  So if you setup four TX rate
  scenarios and the second one works, ts_longretry is only set for
  the number of attempts at that second rate scenario.  The FreeBSD HAL
  code does the correction in ath_hal_proctxdesc() - however, this isn't
  possible with EDMA.
  
  EDMA TX completion is done separate from the original TX descriptor.
  So the real solution is to split out "find ts_rate and ts_longretry"
  from "complete TX descriptor".  Until that's done, put a hack in
  the EDMA TX path that uses the rate scenario information in the ath_buf.
  
  Tested: AR9380, AR9382, AR9485 STA mode

Modified:
  head/sys/dev/ath/if_ath_tx_edma.c

Modified: head/sys/dev/ath/if_ath_tx_edma.c
==============================================================================
--- head/sys/dev/ath/if_ath_tx_edma.c	Sat Nov 10 21:22:10 2012	(r242879)
+++ head/sys/dev/ath/if_ath_tx_edma.c	Sat Nov 10 22:37:06 2012	(r242880)
@@ -594,13 +594,26 @@ ath_edma_tx_processq(struct ath_softc *s
 		 * in the TX descriptor.  However the TX completion
 		 * FIFO doesn't have this information.  So here we
 		 * do a separate HAL call to populate that information.
+		 *
+		 * The same problem exists with ts_longretry.
+		 * The FreeBSD HAL corrects ts_longretry in the HAL layer;
+		 * the AR9380 HAL currently doesn't.  So until the HAL
+		 * is imported and this can be added, we correct for it
+		 * here.
 		 */
-
 		/* XXX TODO */
 		/* XXX faked for now. Ew. */
 		if (ts.ts_finaltsi < 4) {
 			ts.ts_rate =
 			    bf->bf_state.bfs_rc[ts.ts_finaltsi].ratecode;
+			switch (ts.ts_finaltsi) {
+			case 3: ts.ts_longretry +=
+			    bf->bf_state.bfs_rc[2].tries;
+			case 2: ts.ts_longretry +=
+			    bf->bf_state.bfs_rc[1].tries;
+			case 1: ts.ts_longretry +=
+			    bf->bf_state.bfs_rc[0].tries;
+			}
 		} else {
 			device_printf(sc->sc_dev, "%s: finaltsi=%d\n",
 			    __func__,