PERFORCE change 64927 for review

[Sam Leffler]

http://perforce.freebsd.org/chv.cgi?CH=64927

Change 64927 by sam at sam_ebb on 2004/11/12 00:46:02

	o add some assertions to track bus_dma failures (need to recover
	  but for now at least catch them))
	o add debug code to watch for whomever is smashing m_next in rx mbufs

Affected files ...

.. //depot/projects/wifi/sys/dev/ath/if_ath.c#19 edit

Differences ...

==== //depot/projects/wifi/sys/dev/ath/if_ath.c#19 (text+ko) ====

@@ -1561,7 +1561,9 @@
 	struct ath_buf *bf = arg;
 
 	KASSERT(nseg <= ATH_MAX_SCATTER,
-		("ath_mbuf_load_cb: too many DMA segments %u", nseg));
+		("%s: too many DMA segments %u", __func__, nseg));
+	KASSERT(error == 0,
+		("%s: error %u on bus_dma callback", __func__, error));
 	bf->bf_mapsize = mapsize;
 	bf->bf_nseg = nseg;
 	bcopy(seg, bf->bf_segs, nseg * sizeof (seg[0]));
@@ -1676,6 +1678,7 @@
 	else
 		ath_setslottime(sc);
 }
+}
 
 /*
  * Allocate and setup an initial beacon frame.
@@ -1942,6 +1945,8 @@
 ath_load_cb(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
 {
 	bus_addr_t *paddr = (bus_addr_t*) arg;
+	KASSERT(error == 0,
+		("%s: error %u on bus_dma callback", __func__, error));
 	*paddr = segs->ds_addr;
 }
 
@@ -2154,9 +2159,11 @@
 	struct ath_hal *ah = sc->sc_ah;
 	int error;
 	struct mbuf *m;
+struct mbuf *morig; /*XXX*/
 	struct ath_desc *ds;
 
 	m = bf->bf_m;
+morig = m;	/* XXX */
 	if (m == NULL) {
 		/*
 		 * NB: by assigning a page to the rx dma buffer we
@@ -2172,6 +2179,7 @@
 			sc->sc_stats.ast_rx_nombuf++;
 			return ENOMEM;
 		}
+		KASSERT(m->m_next == NULL, ("m_next %p (1)", m->m_next));
 		bf->bf_m = m;
 		m->m_pkthdr.len = m->m_len = m->m_ext.ext_size;
 
@@ -2188,6 +2196,7 @@
 		KASSERT(bf->bf_nseg == 1, ("%s: multi-segment packet; nseg %u",
 			__func__, bf->bf_nseg));
 	}
+	KASSERT(m->m_next == NULL, ("m_next %p morig %p (2)", m->m_next, morig));
 	bus_dmamap_sync(sc->sc_dmat, bf->bf_dmamap, BUS_DMASYNC_PREREAD);
 
 	/*
@@ -2333,6 +2342,10 @@
 #endif
 		if (status == HAL_EINPROGRESS)
 			break;
+		if (m->m_next != NULL) {	/* XXX */
+			if_printf(ifp, "m_next %p, patching!\n", m->m_next);
+			m->m_next = NULL;
+		}
 		STAILQ_REMOVE_HEAD(&sc->sc_rxbuf, bf_list);
 		if (ds->ds_rxstat.rs_more) {
 			/*
@@ -2401,6 +2414,7 @@
 				goto rx_next;
 		}
 rx_accept:
+		KASSERT(m->m_next == NULL, ("m_next %p (3)", m->m_next));
 		/*
 		 * Sync and unmap the frame.  At this point we're
 		 * committed to passing the mbuf somewhere so clear