svn commit: r238344 - head/sys/dev/ath

[Adrian Chadd]

Author: adrian
Date: Tue Jul 10 07:45:47 2012
New Revision: 238344
URL: http://svn.freebsd.org/changeset/base/238344

Log:
  Add some debugging and comments about what's going on when reinitialising
  the FIFO.
  
  I still see some corner cases where no RX occurs when it should be
  occuring.  It's quite possible that there's a subtle race condition
  somewhere; or maybe I'm not programming the RX queues right.
  
  There's also no locking here yet, so any reset/configuration path
  state change (ie, enabling/disabling receive from the ioctl, net80211
  taskqueue, etc) could quite possibly confuse things.

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

Modified: head/sys/dev/ath/if_ath_rx_edma.c
==============================================================================
--- head/sys/dev/ath/if_ath_rx_edma.c	Tue Jul 10 07:43:31 2012	(r238343)
+++ head/sys/dev/ath/if_ath_rx_edma.c	Tue Jul 10 07:45:47 2012	(r238344)
@@ -190,6 +190,12 @@ ath_edma_reinit_fifo(struct ath_softc *s
 	i = re->m_fifo_head;
 	for (j = 0; j < re->m_fifo_depth; j++) {
 		bf = re->m_fifo[i];
+		DPRINTF(sc, ATH_DEBUG_EDMA_RX,
+		    "%s: Q%d: pos=%i, addr=0x%x\n",
+		    __func__,
+		    qtype,
+		    i,
+		    bf->bf_daddr);
 		ath_hal_putrxbuf(sc->sc_ah, bf->bf_daddr, qtype);
 		INCR(i, re->m_fifolen);
 	}
@@ -221,8 +227,21 @@ ath_edma_startrecv(struct ath_softc *sc)
 	/*
 	 * Entries should only be written out if the
 	 * FIFO is empty.
+	 *
+	 * XXX This isn't correct. I should be looking
+	 * at the value of AR_RXDP_SIZE (0x0070) to determine
+	 * how many entries are in here.
+	 *
+	 * A warm reset will clear the registers but not the FIFO.
+	 *
+	 * And I believe this is actually the address of the last
+	 * handled buffer rather than the current FIFO pointer.
+	 * So if no frames have been (yet) seen, we'll reinit the
+	 * FIFO.
+	 *
+	 * I'll chase that up at some point.
 	 */
-	if (ath_hal_getrxbuf(sc->sc_ah, HAL_RX_QUEUE_HP) == 0){
+	if (ath_hal_getrxbuf(sc->sc_ah, HAL_RX_QUEUE_HP) == 0) {
 		DPRINTF(sc, ATH_DEBUG_EDMA_RX,
 		    "%s: Re-initing HP FIFO\n", __func__);
 		ath_edma_reinit_fifo(sc, HAL_RX_QUEUE_HP);