patch-2.1.101 linux/drivers/scsi/mesh.c

• Lines: 1574
• Date: Fri May 8 00:22:12 1998
• Orig file: v2.1.100/linux/drivers/scsi/mesh.c
• Orig date: Tue Apr 14 14:29:22 1998

diff -u --recursive --new-file v2.1.100/linux/drivers/scsi/mesh.c linux/drivers/scsi/mesh.c
@@ -21,15 +21,25 @@
 #include <linux/reboot.h>
 #include <asm/dbdma.h>
 #include <asm/io.h>
+#include <asm/pgtable.h>
 #include <asm/prom.h>
 #include <asm/system.h>
+#include <asm/irq.h>
+#include <asm/hydra.h>
+#include <asm/processor.h>
 #include <asm/spinlock.h>
 
 #include "scsi.h"
 #include "hosts.h"
 #include "mesh.h"
 
-#if 0
+/*
+ * To do:
+ * - handle aborts correctly
+ * - retry arbitration if lost (unless higher levels do this for us)
+ */
+
+#if 1
 #undef KERN_DEBUG
 #define KERN_DEBUG KERN_WARNING
 #endif
@@ -56,6 +66,22 @@
 	S_IFDIR | S_IRUGO | S_IXUGO, 2
 };
 
+#define MESH_DBG
+#define N_DBG_LOG	50
+#define N_DBG_SLOG	20
+#define NUM_DBG_EVENTS	13
+#undef	DBG_USE_TB		/* bombs on 601 */
+
+struct dbglog {
+	char	*fmt;
+	u32	tb;
+	u8	phase;
+	u8	bs0;
+	u8	bs1;
+	u8	tgt;
+	int	d;
+};
+
 enum mesh_phase {
 	idle,
 	arbitrating,
@@ -74,6 +100,7 @@
 	msg_out_xxx,
 	msg_out_last,
 	msg_in,
+	msg_in_bad,
 };
 
 enum sdtr_phase {
@@ -84,11 +111,16 @@
 
 struct mesh_target {
 	enum sdtr_phase sdtr_state;
-	enum mesh_phase phase;
 	int	sync_params;
-	int	data_goes_out;
+	int	data_goes_out;		/* guess as to data direction */
 	Scsi_Cmnd *current_req;
 	u32	saved_ptr;
+	int	want_abort;
+#ifdef MESH_DBG
+	int	log_ix;
+	int	n_log;
+	struct dbglog log[N_DBG_LOG];
+#endif
 };
 
 struct mesh_state {
@@ -105,9 +137,10 @@
 	int	conn_tgt;		/* target we're connected to */
 	Scsi_Cmnd *current_req;		/* req we're currently working on */
 	int	data_ptr;
-	int	data_goes_out;		/* guess as to data direction */
 	int	dma_started;
 	int	dma_count;
+	int	stat;
+	int	aborting;
 	int	expect_reply;
 	int	n_msgin;
 	u8	msgin[16];
@@ -116,18 +149,41 @@
 	u8	msgout[16];
 	struct dbdma_cmd *dma_cmds;	/* space for dbdma commands, aligned */
 	int	clk_freq;
-	struct mesh_target tgts[8];
-	struct tq_struct tqueue;
 	Scsi_Cmnd *completed_q;
 	Scsi_Cmnd *completed_qtail;
+	struct mesh_target tgts[8];
+	struct tq_struct tqueue;
+#ifdef MESH_DBG
+	int	log_ix;
+	int	n_log;
+	struct dbglog log[N_DBG_SLOG];
+#endif
 };
 
+#ifdef MESH_DBG
+
+static void dlog(struct mesh_state *ms, char *fmt, int a);
+static void dumplog(struct mesh_state *ms, int tgt);
+static void dumpslog(struct mesh_state *ms);
+#define MKWORD(a, b, c, d)	(((a) << 24) + ((b) << 16) + ((c) << 8) + (d))
+
+#else
+static inline void dlog(struct mesh_state *ms, char *fmt, int a)
+{}
+static inline void dumplog(struct mesh_state *ms, int tgt)
+{}
+static inline void dumpslog(struct mesh_state *ms)
+{}
+
+#endif /* MESH_DBG */
+
 static struct mesh_state *all_meshes;
 
 static void mesh_init(struct mesh_state *);
 static int mesh_notify_reboot(struct notifier_block *, unsigned long, void *);
 static void mesh_dump_regs(struct mesh_state *);
 static void mesh_start(struct mesh_state *);
+static void mesh_start_cmd(struct mesh_state *, Scsi_Cmnd *);
 static void finish_cmds(void *);
 static void add_sdtr_msg(struct mesh_state *);
 static void set_sdtr(struct mesh_state *, int, int);
@@ -138,14 +194,17 @@
 static void phase_mismatch(struct mesh_state *);
 static void reselected(struct mesh_state *);
 static void handle_reset(struct mesh_state *);
+static void handle_error(struct mesh_state *);
+static void handle_exception(struct mesh_state *);
 static void mesh_interrupt(int, void *, struct pt_regs *);
 static void do_mesh_interrupt(int, void *, struct pt_regs *);
 static void handle_msgin(struct mesh_state *);
-static void mesh_done(struct mesh_state *);
+static void mesh_done(struct mesh_state *, int);
 static void mesh_completed(struct mesh_state *, Scsi_Cmnd *);
 static void set_dma_cmds(struct mesh_state *, Scsi_Cmnd *);
 static void halt_dma(struct mesh_state *);
 static int data_goes_out(Scsi_Cmnd *);
+static void do_abort(struct mesh_state *ms);
 
 static struct notifier_block mesh_notifier = {
 	mesh_notify_reboot,
@@ -164,13 +223,25 @@
 
 	nmeshes = 0;
 	prev_statep = &all_meshes;
-	for (mesh = find_devices("mesh"); mesh != 0; mesh = mesh->next) {
-		if (mesh->n_addrs != 2 || mesh->n_intrs != 2)
-			panic("mesh: expected 2 addrs and intrs (got %d/%d)",
-			      mesh->n_addrs, mesh->n_intrs);
+	/*
+	 * On powermacs, the MESH node has device_type "mesh".
+	 * On chrp machines, its device_type is "scsi" with
+	 * "chrp,mesh0" as its `compatible' property.
+	 */
+	mesh = find_devices("mesh");
+	if (mesh == 0)
+		mesh = find_compatible_devices("scsi", "chrp,mesh0");
+	for (; mesh != 0; mesh = mesh->next) {
+		if (mesh->n_addrs != 2 || mesh->n_intrs != 2) {
+			printk(KERN_ERR "mesh: expected 2 addrs and 2 intrs"
+			       " (got %d,%d)", mesh->n_addrs, mesh->n_intrs);
+			continue;
+		}
 		mesh_host = scsi_register(tp, sizeof(struct mesh_state));
-		if (mesh_host == 0)
-			panic("couldn't register mesh host");
+		if (mesh_host == 0) {
+			printk(KERN_ERR "mesh: couldn't register host");
+			continue;
+		}
 		mesh_host->unique_id = nmeshes;
 		note_scsi_host(mesh, mesh_host);
 
@@ -180,11 +251,11 @@
 		memset(ms, 0, sizeof(*ms));
 		ms->host = mesh_host;
 		ms->mesh = (volatile struct mesh_regs *)
-			mesh->addrs[0].address;
-		ms->meshintr = mesh->intrs[0];
+			ioremap(mesh->addrs[0].address, 0x1000);
 		ms->dma = (volatile struct dbdma_regs *)
-			mesh->addrs[1].address;
-		ms->dmaintr = mesh->intrs[1];
+			ioremap(mesh->addrs[1].address, 0x1000);
+		ms->meshintr = mesh->intrs[0].line;
+		ms->dmaintr = mesh->intrs[1].line;
 
 		/* Space for dma command list: +1 for stop command,
 		   +1 to allow for aligning. */
@@ -213,8 +284,8 @@
 			printk(KERN_ERR "MESH: can't get irq %d\n", ms->meshintr);
 		}
 
-		cfp = (int *) get_property(mesh, "clock-frequency", NULL);
-		if (cfp) {
+		if ((cfp = (int *) get_property(mesh, "clock-frequency",
+						NULL))) {
 			ms->clk_freq = *cfp;
 		} else {
 			printk(KERN_INFO "mesh: assuming 50MHz clock frequency\n");
@@ -230,7 +301,7 @@
 
 		++nmeshes;
 	}
-	if (nmeshes > 0)
+	if (_machine == _MACH_Pmac && nmeshes > 0)
 		register_reboot_notifier(&mesh_notifier);
 
 	return nmeshes;
@@ -242,16 +313,6 @@
 	unsigned long flags;
 	struct mesh_state *ms;
 
-#if 0
-	if (data_goes_out(cmd)) {
-		printk(KERN_DEBUG "mesh_queue %p: command is", cmd);
-		for (i = 0; i < cmd->cmd_len; ++i)
-			printk(" %.2x", cmd->cmnd[i]);
-		printk("\n" KERN_DEBUG "use_sg=%d request_bufflen=%d request_buffer=%p\n",
-		       cmd->use_sg, cmd->request_bufflen, cmd->request_buffer);
-	}
-#endif
-
 	cmd->scsi_done = done;
 	cmd->host_scribble = NULL;
 
@@ -275,8 +336,12 @@
 int
 mesh_abort(Scsi_Cmnd *cmd)
 {
+	struct mesh_state *ms = (struct mesh_state *) cmd->host->hostdata;
+
 	printk(KERN_DEBUG "mesh_abort(%p)\n", cmd);
-	mesh_dump_regs((struct mesh_state *)(cmd->host->hostdata));
+	mesh_dump_regs(ms);
+	dumplog(ms, cmd->target);
+	dumpslog(ms);
 	return SCSI_ABORT_SNOOZE;
 }
 
@@ -290,22 +355,24 @@
 
 	printk(KERN_DEBUG "mesh: state at %p, regs at %p, dma at %p\n",
 	       ms, mr, md);
-	printk(KERN_DEBUG "    ct=%4x seq=%2x bs=%4x fc=%2x exc=%2x err=%2x sp=%2x\n",
+	printk(KERN_DEBUG "    ct=%4x seq=%2x bs=%4x fc=%2x "
+	       "exc=%2x err=%2x im=%2x int=%2x sp=%2x\n",
 	       (mr->count_hi << 8) + mr->count_lo, mr->sequence,
 	       (mr->bus_status1 << 8) + mr->bus_status0, mr->fifo_count,
-	       mr->exception, mr->error, mr->sync_params);
+	       mr->exception, mr->error, mr->intr_mask, mr->interrupt,
+	       mr->sync_params);
 	printk(KERN_DEBUG "    dma stat=%x cmdptr=%x\n",
 	       in_le32(&md->status), in_le32(&md->cmdptr));
 	printk(KERN_DEBUG "    phase=%d msgphase=%d conn_tgt=%d data_ptr=%d\n",
 	       ms->phase, ms->msgphase, ms->conn_tgt, ms->data_ptr);
-	printk(KERN_DEBUG "    goes_out=%d dma_st=%d dma_ct=%d n_msgout=%d\n",
-	       ms->data_goes_out, ms->dma_started, ms->dma_count, ms->n_msgout);
+	printk(KERN_DEBUG "    dma_st=%d dma_ct=%d n_msgout=%d\n",
+	       ms->dma_started, ms->dma_count, ms->n_msgout);
 	for (t = 0; t < 8; ++t) {
 		tp = &ms->tgts[t];
 		if (tp->current_req == NULL)
 			continue;
-		printk(KERN_DEBUG "    target %d: req=%p phase=%d saved_ptr=%d\n",
-		       t, tp->current_req, tp->phase, tp->saved_ptr);
+		printk(KERN_DEBUG "    target %d: req=%p goes_out=%d saved_ptr=%d\n",
+		       t, tp->current_req, tp->data_goes_out, tp->saved_ptr);
 	}
 }
 
@@ -322,14 +389,17 @@
 	ret = SCSI_RESET_BUS_RESET;
 	save_flags(flags);
 	cli();
+	out_le32(&md->control, (RUN|PAUSE|FLUSH|WAKE) << 16);	/* stop dma */
 	out_8(&mr->exception, 0xff);	/* clear all exception bits */
 	out_8(&mr->error, 0xff);	/* clear all error bits */
-	out_le32(&md->control, (RUN|PAUSE|FLUSH|WAKE) << 16);
 	if (how & SCSI_RESET_SUGGEST_HOST_RESET) {
 		out_8(&mr->sequence, SEQ_RESETMESH);
 		ret |= SCSI_RESET_HOST_RESET;
 		udelay(1);
 		out_8(&mr->intr_mask, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
+		out_8(&mr->source_id, ms->host->this_id);
+		out_8(&mr->sel_timeout, 25);	/* 250ms */
+		out_8(&mr->sync_params, ASYNC_PARAMS);
 	}
 	out_8(&mr->bus_status1, BS1_RST);	/* assert RST */
 	udelay(30);			/* leave it on for >= 25us */
@@ -341,7 +411,6 @@
 	} else
 #endif
 	{
-		out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
 		handle_reset(ms);
 		restore_flags(flags);
 		finish_cmds(ms);
@@ -361,7 +430,7 @@
 	struct mesh_state *ms;
 	volatile struct mesh_regs *mr;
 
-	if (code == SYS_DOWN || code == SYS_HALT) {
+	if (code == SYS_DOWN) {
 		printk(KERN_INFO "resetting MESH scsi bus(es)\n");
 		for (ms = all_meshes; ms != 0; ms = ms->next) {
 			mr = ms->mesh;
@@ -405,29 +474,42 @@
 mesh_start(struct mesh_state *ms)
 {
 	Scsi_Cmnd *cmd, *prev, *next;
-	volatile struct mesh_regs *mr = ms->mesh;
 
-	if (ms->phase != idle || ms->current_req != NULL)
-		panic("inappropriate mesh_start (ms=%p)", ms);
+	if (ms->phase != idle || ms->current_req != NULL) {
+		printk(KERN_ERR "inappropriate mesh_start (phase=%d, ms=%p)",
+		       ms->phase, ms);
+		return;
+	}
 
-	prev = NULL;
-	for (cmd = ms->request_q; ; cmd = (Scsi_Cmnd *) cmd->host_scribble) {
-		if (cmd == NULL)
-			return;
-		if (ms->tgts[cmd->target].current_req == NULL)
-			break;
-		prev = cmd;
+	while (ms->phase == idle) {
+		prev = NULL;
+		for (cmd = ms->request_q; ; cmd = (Scsi_Cmnd *) cmd->host_scribble) {
+			if (cmd == NULL)
+				return;
+			if (ms->tgts[cmd->target].current_req == NULL)
+				break;
+			prev = cmd;
+		}
+		next = (Scsi_Cmnd *) cmd->host_scribble;
+		if (prev == NULL)
+			ms->request_q = next;
+		else
+			prev->host_scribble = (void *) next;
+		if (next == NULL)
+			ms->request_qtail = prev;
+
+		mesh_start_cmd(ms, cmd);
 	}
-	next = (Scsi_Cmnd *) cmd->host_scribble;
-	if (prev == NULL)
-		ms->request_q = next;
-	else
-		prev->host_scribble = (void *) next;
-	if (next == NULL)
-		ms->request_qtail = prev;
+}
+
+static void
+mesh_start_cmd(struct mesh_state *ms, Scsi_Cmnd *cmd)
+{
+	volatile struct mesh_regs *mr = ms->mesh;
+	int t;
 
 	ms->current_req = cmd;
-	ms->data_goes_out = data_goes_out(cmd);
+	ms->tgts[cmd->target].data_goes_out = data_goes_out(cmd);
 	ms->tgts[cmd->target].current_req = cmd;
 
 #if 1
@@ -442,9 +524,6 @@
 	}
 #endif
 
-	/* Off we go */
-	out_8(&mr->sequence, SEQ_ARBITRATE);
-
 	ms->phase = arbitrating;
 	ms->msgphase = msg_none;
 	ms->data_ptr = 0;
@@ -454,6 +533,118 @@
 	ms->expect_reply = 0;
 	ms->conn_tgt = cmd->target;
 	ms->tgts[cmd->target].saved_ptr = 0;
+	ms->stat = DID_OK;
+	ms->aborting = 0;
+#ifdef MESH_DBG
+	ms->tgts[cmd->target].n_log = 0;
+	dlog(ms, "start cmd=%x", (int) cmd);
+#endif
+
+	/* Off we go */
+	dlog(ms, "about to arb, intr/exc/err/fc=%.8x",
+	     MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
+	out_8(&mr->interrupt, INT_CMDDONE);
+	out_8(&mr->sequence, SEQ_ENBRESEL);
+	udelay(1);
+
+	if (mr->bus_status1 & (BS1_BSY | BS1_SEL)) {
+		/*
+		 * Some other device has the bus or is arbitrating for it -
+		 * probably a target which is about to reselect us.
+		 */
+		dlog(ms, "busy b4 arb, intr/exc/err/fc=%.8x",
+		     MKWORD(mr->interrupt, mr->exception,
+			    mr->error, mr->fifo_count));
+		for (t = 100; t > 0; --t) {
+			if ((mr->bus_status1 & (BS1_BSY | BS1_SEL)) == 0)
+				break;
+			if (in_8(&mr->interrupt) != 0) {
+				dlog(ms, "intr b4 arb, intr/exc/err/fc=%.8x",
+				     MKWORD(mr->interrupt, mr->exception,
+					    mr->error, mr->fifo_count));
+				mesh_interrupt(0, (void *)ms, 0);
+				if (ms->phase != arbitrating)
+					return;
+			}
+			udelay(1);
+		}
+		if (mr->bus_status1 & (BS1_BSY | BS1_SEL)) {
+			/* XXX should try again in a little while */
+			ms->stat = DID_BUS_BUSY;
+			ms->phase = idle;
+			mesh_done(ms, 0);
+			return;
+		}
+	}
+
+	/*
+	 * Apparently the mesh has a bug where it will assert both its
+	 * own bit and the target's bit on the bus during arbitration.
+	 */
+	out_8(&mr->dest_id, mr->source_id);
+
+	/*
+	 * There appears to be a race with reselection sometimes,
+	 * where a target reselects us just as we issue the
+	 * arbitrate command.  It seems that then the arbitrate
+	 * command just hangs waiting for the bus to be free
+	 * without giving us a reselection exception.
+	 * The only way I have found to get it to respond correctly
+	 * is this: disable reselection before issuing the arbitrate
+	 * command, then after issuing it, if it looks like a target
+	 * is trying to reselect us, reset the mesh and then enable
+	 * reselection.
+	 */
+	out_8(&mr->sequence, SEQ_DISRESEL);
+	if (in_8(&mr->interrupt) != 0) {
+		dlog(ms, "intr after disresel, intr/exc/err/fc=%.8x",
+		     MKWORD(mr->interrupt, mr->exception,
+			    mr->error, mr->fifo_count));
+		mesh_interrupt(0, (void *)ms, 0);
+		if (ms->phase != arbitrating)
+			return;
+		dlog(ms, "after intr after disresel, intr/exc/err/fc=%.8x",
+		     MKWORD(mr->interrupt, mr->exception,
+			    mr->error, mr->fifo_count));
+	}
+
+	out_8(&mr->sequence, SEQ_ARBITRATE);
+
+	for (t = 30; t > 0; --t) {
+		if (in_8(&mr->interrupt) != 0)
+			break;
+		udelay(1);
+	}
+	dlog(ms, "after arb, intr/exc/err/fc=%.8x",
+	     MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
+	if (mr->interrupt == 0 && (mr->bus_status1 & BS1_SEL)
+	    && (mr->bus_status0 & BS0_IO)) {
+		/* looks like a reselection - try resetting the mesh */
+		dlog(ms, "resel? after arb, intr/exc/err/fc=%.8x",
+		     MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
+		out_8(&mr->sequence, SEQ_RESETMESH);
+		udelay(10);
+		out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
+		out_8(&mr->intr_mask, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
+		out_8(&mr->sequence, SEQ_ENBRESEL);
+		for (t = 10; t > 0 && mr->interrupt == 0; --t)
+			udelay(1);
+		dlog(ms, "tried reset after arb, intr/exc/err/fc=%.8x",
+		     MKWORD(mr->interrupt, mr->exception, mr->error, mr->fifo_count));
+#ifndef MESH_MULTIPLE_HOSTS
+		if (mr->interrupt == 0 && (mr->bus_status1 & BS1_SEL)
+		    && (mr->bus_status0 & BS0_IO)) {
+			printk(KERN_ERR "mesh: controller not responding"
+			       " to reselection!\n");
+			/*
+			 * If this is a target reselecting us, and the
+			 * mesh isn't responding, the higher levels of
+			 * the scsi code will eventually time out and
+			 * reset the bus.
+			 */
+		}
+#endif
+	}
 }
 
 static void
@@ -541,10 +732,9 @@
 	Scsi_Cmnd *cmd = ms->current_req;
 	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
 
-	if (cmd == 0) {
-		printk(KERN_ERR "mesh: start_phase but no cmd?\n");
-		return;
-	}
+	dlog(ms, "start_phase err/exc/fc/seq = %.8x",
+	     MKWORD(mr->error, mr->exception, mr->fifo_count, mr->sequence));
+	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
 	seq = SEQ_ACTIVE_NEG + (ms->n_msgout? SEQ_ATN: 0);
 	switch (ms->msgphase) {
 	case msg_none:
@@ -563,20 +753,44 @@
 		 * the last byte of the message, we have to do the
 		 * last byte specially.
 		 */
-		if (DEBUG_TARGET(cmd)) {
+		if (ms->n_msgout <= 0) {
+			printk(KERN_ERR "mesh: msg_out but n_msgout=%d\n",
+			       ms->n_msgout);
+			mesh_dump_regs(ms);
+			ms->msgphase = msg_none;
+			break;
+		}
+		if (ALLOW_DEBUG(ms->conn_tgt)) {
 			printk(KERN_DEBUG "mesh: sending %d msg bytes:",
 			       ms->n_msgout);
 			for (i = 0; i < ms->n_msgout; ++i)
 				printk(" %x", ms->msgout[i]);
 			printk("\n");
 		}
+		dlog(ms, "msgout msg=%.8x", MKWORD(ms->n_msgout, ms->msgout[0],
+						ms->msgout[1], ms->msgout[2]));
 		out_8(&mr->count_hi, 0);
-		if (ms->n_msgout == 1) {
-			out_8(&mr->count_lo, 1);
-			out_8(&mr->sequence, SEQ_MSGOUT + SEQ_ACTIVE_NEG);
+		out_8(&mr->sequence, SEQ_FLUSHFIFO);
+		udelay(1);
+		/*
+		 * If ATN is not already asserted, we assert it, then
+		 * issue a SEQ_MSGOUT to get the mesh to drop ACK.
+		 */
+		if ((mr->bus_status0 & BS0_ATN) == 0) {
+			out_8(&mr->bus_status0, BS0_ATN); /* explicit ATN */
 			udelay(1);
-			out_8(&mr->fifo, ms->msgout[0]);
-			ms->msgphase = msg_out_last;
+			out_8(&mr->count_lo, 1);
+			out_8(&mr->sequence, SEQ_MSGOUT + seq);
+			out_8(&mr->bus_status0, 0); /* release explicit ATN */
+		}
+		if (ms->n_msgout == 1) {
+			/*
+			 * We can't issue the SEQ_MSGOUT without ATN
+			 * until the target has asserted REQ.  The logic
+			 * in cmd_complete handles both situations:
+			 * REQ already asserted or not.
+			 */
+			cmd_complete(ms);
 		} else {
 			out_8(&mr->count_lo, ms->n_msgout - 1);
 			out_8(&mr->sequence, SEQ_MSGOUT + seq);
@@ -592,16 +806,23 @@
 
 	switch (ms->phase) {
 	case selecting:
-		out_8(&mr->dest_id, cmd->target);
+		out_8(&mr->dest_id, ms->conn_tgt);
 		out_8(&mr->sequence, SEQ_SELECT + SEQ_ATN);
 		break;
 	case commanding:
 		out_8(&mr->sync_params, tp->sync_params);
 		out_8(&mr->count_hi, 0);
-		out_8(&mr->count_lo, cmd->cmd_len);
-		out_8(&mr->sequence, SEQ_COMMAND + seq);
-		for (i = 0; i < cmd->cmd_len; ++i)
-			out_8(&mr->fifo, cmd->cmnd[i]);
+		if (cmd) {
+			out_8(&mr->count_lo, cmd->cmd_len);
+			out_8(&mr->sequence, SEQ_COMMAND + seq);
+			for (i = 0; i < cmd->cmd_len; ++i)
+				out_8(&mr->fifo, cmd->cmnd[i]);
+		} else {
+			out_8(&mr->count_lo, 6);
+			out_8(&mr->sequence, SEQ_COMMAND + seq);
+			for (i = 0; i < 6; ++i)
+				out_8(&mr->fifo, 0);
+		}
 		break;
 	case dataing:
 		/* transfer data, if any */
@@ -618,7 +839,7 @@
 		ms->data_ptr += nb;
 		out_8(&mr->count_lo, nb);
 		out_8(&mr->count_hi, nb >> 8);
-		out_8(&mr->sequence, (ms->data_goes_out?
+		out_8(&mr->sequence, (tp->data_goes_out?
 				SEQ_DATAOUT: SEQ_DATAIN) + SEQ_DMA_MODE + seq);
 		break;
 	case statusing:
@@ -630,11 +851,15 @@
 	case disconnecting:
 		out_8(&mr->sequence, SEQ_ENBRESEL);
 		udelay(1);
+		dlog(ms, "enbresel intr/exc/err/fc=%.8x",
+		     MKWORD(mr->interrupt, mr->exception, mr->error,
+			    mr->fifo_count));
 		out_8(&mr->sequence, SEQ_BUSFREE);
 		break;
 	default:
 		printk(KERN_ERR "mesh: start_phase called with phase=%d\n",
 		       ms->phase);
+		dumpslog(ms);
 	}
 
 }
@@ -681,6 +906,7 @@
 	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
 	int seq, n, t;
 
+	dlog(ms, "cmd_complete fc=%x", mr->fifo_count);
 	seq = SEQ_ACTIVE_NEG + (ms->n_msgout? SEQ_ATN: 0);
 	switch (ms->msgphase) {
 	case msg_out_xxx:
@@ -703,6 +929,13 @@
 		}
 		break;
 
+	case msg_in_bad:
+		out_8(&mr->sequence, SEQ_FLUSHFIFO);
+		udelay(1);
+		out_8(&mr->count_lo, 1);
+		out_8(&mr->sequence, SEQ_MSGIN + SEQ_ATN + SEQ_ACTIVE_NEG);
+		break;
+
 	case msg_out:
 		/*
 		 * To get the right timing on ATN wrt ACK, we have
@@ -720,6 +953,28 @@
 		t = 30;		/* wait up to 30us */
 		while ((mr->bus_status0 & BS0_REQ) == 0 && --t >= 0)
 			udelay(1);
+		dlog(ms, "last_mbyte err/exc/fc/cl=%.8x",
+		     MKWORD(mr->error, mr->exception,
+			    mr->fifo_count, mr->count_lo));
+		if (in_8(&mr->interrupt) & (INT_ERROR | INT_EXCEPTION)) {
+			/* whoops, target didn't do what we expected */
+			ms->last_n_msgout = ms->n_msgout;
+			ms->n_msgout = 0;
+			if (in_8(&mr->interrupt) & INT_ERROR) {
+				printk(KERN_ERR "mesh: error %x in msg_out\n",
+				       in_8(&mr->error));
+				handle_error(ms);
+				return;
+			}
+			if (in_8(&mr->exception) != EXC_PHASEMM)
+				printk(KERN_ERR "mesh: exc %x in msg_out\n",
+				       in_8(&mr->exception));
+			else
+				printk(KERN_DEBUG "mesh: bs0=%x in msg_out\n",
+				       in_8(&mr->bus_status0));
+			handle_exception(ms);
+			return;
+		}
 		if (mr->bus_status0 & BS0_REQ) {
 			out_8(&mr->sequence, SEQ_MSGOUT + SEQ_ACTIVE_NEG);
 			udelay(1);
@@ -740,11 +995,19 @@
 
 	case msg_none:
 		switch (ms->phase) {
+		case idle:
+			printk(KERN_ERR "mesh: interrupt in idle phase?\n");
+			dumpslog(ms);
+			return;
 		case selecting:
-			ms->msgout[0] = IDENTIFY(ALLOW_RESEL(cmd->target), cmd->lun);
+			ms->msgout[0] = IDENTIFY(ALLOW_RESEL(ms->conn_tgt),
+						 (cmd? cmd->lun: 0));
 			ms->n_msgout = 1;
 			ms->expect_reply = 0;
-			if (tp->sdtr_state == do_sdtr) {
+			if (ms->aborting) {
+				ms->msgout[0] = ABORT;
+				ms->n_msgout++;
+			} else if (tp->sdtr_state == do_sdtr) {
 				/* add SDTR message */
 				add_sdtr_msg(ms);
 				ms->expect_reply = 1;
@@ -772,18 +1035,32 @@
 				start_phase(ms);
 				return;
 			}
+			/*
+			 * We can get a phase mismatch here if the target
+			 * changes to the status phase, even though we have
+			 * had a command complete interrupt.  Then, if we
+			 * issue the SEQ_STATUS command, we'll get a sequence
+			 * error interrupt.  Which isn't so bad except that
+			 * occasionally the mesh actually executes the
+			 * SEQ_STATUS *as well as* giving us the sequence
+			 * error and phase mismatch exception.
+			 */
+			out_8(&mr->sequence, 0);
+			out_8(&mr->interrupt,
+			      INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
 			halt_dma(ms);
 			break;
 		case statusing:
-			cmd->SCp.Status = mr->fifo;
-			cmd->result = (DID_OK << 16) + cmd->SCp.Status;
+			if (cmd) {
+				cmd->SCp.Status = mr->fifo;
+				if (DEBUG_TARGET(cmd))
+					printk(KERN_DEBUG "mesh: status is %x\n",
+					       cmd->SCp.Status);
+			}
 			ms->msgphase = msg_in;
-			if (DEBUG_TARGET(cmd))
-				printk(KERN_DEBUG "mesh: status is %x\n",
-				       cmd->SCp.Status);
 			break;
 		case busfreeing:
-			mesh_done(ms);
+			mesh_done(ms, 1);
 			return;
 		case disconnecting:
 			ms->current_req = 0;
@@ -804,6 +1081,8 @@
 	volatile struct mesh_regs *mr = ms->mesh;
 	int phase;
 
+	dlog(ms, "phasemm ch/cl/seq/fc=%.8x",
+	     MKWORD(mr->count_hi, mr->count_lo, mr->sequence, mr->fifo_count));
 	phase = mr->bus_status0 & BS0_PHASE;
 	if (ms->msgphase == msg_out_xxx && phase == BP_MSGOUT) {
 		/* output the last byte of the message, without ATN */
@@ -831,11 +1110,11 @@
 	ms->msgphase = msg_none;
 	switch (phase) {
 	case BP_DATAIN:
-		ms->data_goes_out = 0;
+		ms->tgts[ms->conn_tgt].data_goes_out = 0;
 		ms->phase = dataing;
 		break;
 	case BP_DATAOUT:
-		ms->data_goes_out = 1;
+		ms->tgts[ms->conn_tgt].data_goes_out = 1;
 		ms->phase = dataing;
 		break;
 	case BP_COMMAND:
@@ -851,18 +1130,23 @@
 	case BP_MSGOUT:
 		ms->msgphase = msg_out;
 		if (ms->n_msgout == 0) {
-			if (ms->last_n_msgout == 0) {
-				printk(KERN_DEBUG "mesh: no msg to repeat\n");
-				ms->msgout[0] = NOP;
-				ms->last_n_msgout = 1;
+			if (ms->aborting) {
+				do_abort(ms);
+			} else {
+				if (ms->last_n_msgout == 0) {
+					printk(KERN_DEBUG
+					       "mesh: no msg to repeat\n");
+					ms->msgout[0] = NOP;
+					ms->last_n_msgout = 1;
+				}
+				ms->n_msgout = ms->last_n_msgout;
 			}
-			ms->n_msgout = ms->last_n_msgout;
 		}
 		break;
 	default:
 		printk(KERN_DEBUG "mesh: unknown scsi phase %x\n", phase);
-		ms->current_req->result = DID_ERROR << 16;
-		mesh_done(ms);
+		ms->stat = DID_ERROR;
+		mesh_done(ms, 1);
 		return;
 	}
 
@@ -873,82 +1157,126 @@
 reselected(struct mesh_state *ms)
 {
 	volatile struct mesh_regs *mr = ms->mesh;
-	Scsi_Cmnd *cmd = ms->current_req;
+	Scsi_Cmnd *cmd;
 	struct mesh_target *tp;
-	int b, t;
+	int b, t, prev;
 
 	switch (ms->phase) {
 	case idle:
+		break;
 	case arbitrating:
+		if ((cmd = ms->current_req) != NULL) {
+			/* put the command back on the queue */
+			cmd->host_scribble = (void *) ms->request_q;
+			if (ms->request_q == NULL)
+				ms->request_qtail = cmd;
+			ms->request_q = cmd;
+			tp = &ms->tgts[cmd->target];
+			tp->current_req = NULL;
+		}
 		break;
 	case busfreeing:
 		ms->phase = reselecting;
-		mesh_done(ms);
-		cmd = NULL;
+		mesh_done(ms, 0);
 		break;
 	case disconnecting:
-		cmd = NULL;
 		break;
 	default:
-		printk(KERN_ERR "mesh: reselected in phase %d/%d\n",
-		       ms->msgphase, ms->phase);
-	}
-	if (cmd) {
-		/* put the command back on the queue */
-		cmd->host_scribble = (void *) ms->request_q;
-		if (ms->request_q == NULL)
-			ms->request_qtail = cmd;
-		ms->request_q = cmd;
-		tp = &ms->tgts[cmd->target];
-		tp->current_req = NULL;
-		ms->current_req = NULL;
+		printk(KERN_ERR "mesh: reselected in phase %d/%d tgt %d\n",
+		       ms->msgphase, ms->phase, ms->conn_tgt);
+		dumplog(ms, ms->conn_tgt);
+		dumpslog(ms);
 	}
 
+	ms->current_req = NULL;
+	ms->phase = dataing;
+	ms->msgphase = msg_in;
+	ms->dma_started = 0;
+	ms->n_msgout = 0;
+	ms->last_n_msgout = 0;
+	prev = ms->conn_tgt;
+
+	/*
+	 * We seem to get abortive reselections sometimes.
+	 */
+	while ((mr->bus_status1 & BS1_BSY) == 0) {
+		static int mesh_aborted_resels;
+		mesh_aborted_resels++;
+		out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
+		udelay(1);
+		out_8(&mr->sequence, SEQ_ENBRESEL);
+		udelay(5);
+		dlog(ms, "extra resel err/exc/fc = %.6x",
+		     MKWORD(0, mr->error, mr->exception, mr->fifo_count));
+	}
+	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
+	udelay(1);
+	out_8(&mr->sequence, SEQ_ENBRESEL);
+	udelay(1);
+	out_8(&mr->sync_params, ASYNC_PARAMS);
+
 	/*
 	 * Find out who reselected us.
 	 */
 	if (mr->fifo_count == 0) {
 		printk(KERN_ERR "mesh: reselection but nothing in fifo?\n");
-		return;
+		ms->conn_tgt = ms->host->this_id;
+		goto bogus;
 	}
 	/* get the last byte in the fifo */
 	do {
 		b = in_8(&mr->fifo);
+		dlog(ms, "reseldata %x", b);
 	} while (in_8(&mr->fifo_count));
 	for (t = 0; t < 8; ++t)
 		if ((b & (1 << t)) != 0 && t != ms->host->this_id)
 			break;
 	if (b != (1 << t) + (1 << ms->host->this_id)) {
 		printk(KERN_ERR "mesh: bad reselection data %x\n", b);
-		return;
+		ms->conn_tgt = ms->host->this_id;
+		goto bogus;
 	}
 
+
 	/*
 	 * Set up to continue with that target's transfer.
 	 */
+	ms->conn_tgt = t;
 	tp = &ms->tgts[t];
+	out_8(&mr->sync_params, tp->sync_params);
 	if (ALLOW_DEBUG(t)) {
 		printk(KERN_DEBUG "mesh: reselected by target %d\n", t);
-		printk(KERN_DEBUG "mesh: saved_ptr=%x phase=%d cmd=%p\n",
-		       tp->saved_ptr, tp->phase, tp->current_req);
+		printk(KERN_DEBUG "mesh: saved_ptr=%x goes_out=%d cmd=%p\n",
+		       tp->saved_ptr, tp->data_goes_out, tp->current_req);
 	}
+	ms->current_req = tp->current_req;
 	if (tp->current_req == NULL) {
 		printk(KERN_ERR "mesh: reselected by tgt %d but no cmd!\n", t);
-		return;
+		goto bogus;
 	}
-	ms->current_req = tp->current_req;
-	ms->phase = tp->phase;
-	ms->msgphase = msg_in;
-	ms->data_goes_out = tp->data_goes_out;
 	ms->data_ptr = tp->saved_ptr;
-	ms->conn_tgt = t;
-	ms->dma_started = 0;
-	ms->n_msgout = 0;
-	ms->last_n_msgout = 0;
-	out_8(&mr->sync_params, tp->sync_params);
+	dlog(ms, "resel prev tgt=%d", prev);
+	dlog(ms, "resel err/exc=%.4x", MKWORD(0, 0, mr->error, mr->exception));
+	start_phase(ms);
+	return;
+
+bogus:
+	dumplog(ms, ms->conn_tgt);
+	dumpslog(ms);
+	ms->data_ptr = 0;
+	ms->aborting = 1;
 	start_phase(ms);
 }
 
+static void do_abort(struct mesh_state *ms)
+{
+	ms->msgout[0] = ABORT;
+	ms->n_msgout = 1;
+	ms->aborting = 1;
+	ms->stat = DID_ABORT;
+	dlog(ms, "abort", 0);
+}
+
 static void
 handle_reset(struct mesh_state *ms)
 {
@@ -974,7 +1302,12 @@
 		mesh_completed(ms, cmd);
 	}
 	ms->phase = idle;
+	ms->msgphase = msg_none;
+	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
+	out_8(&mr->sequence, SEQ_FLUSHFIFO);
+	udelay(1);
 	out_8(&mr->sync_params, ASYNC_PARAMS);
+	out_8(&mr->sequence, SEQ_ENBRESEL);
 }
 
 static void
@@ -987,90 +1320,153 @@
 	spin_unlock_irqrestore(&io_request_lock, flags);
 }
 
+static void handle_error(struct mesh_state *ms)
+{
+	int err, exc, count;
+	volatile struct mesh_regs *mr = ms->mesh;
+
+	err = in_8(&mr->error);
+	exc = in_8(&mr->exception);
+	out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
+	dlog(ms, "error err/exc/fc/cl=%.8x",
+	     MKWORD(err, exc, mr->fifo_count, mr->count_lo));
+	if (err & ERR_SCSIRESET) {
+		/* SCSI bus was reset */
+		printk(KERN_INFO "mesh: SCSI bus reset detected: "
+		       "waiting for end...");
+		while ((mr->bus_status1 & BS1_RST) != 0)
+			udelay(1);
+		printk("done\n");
+		handle_reset(ms);
+		/* request_q is empty, no point in mesh_start() */
+		return;
+	}
+	if (err & ERR_UNEXPDISC) {
+		/* Unexpected disconnect */
+		if (exc & EXC_RESELECTED) {
+			reselected(ms);
+			return;
+		}
+		if (!ms->aborting) {
+			printk(KERN_WARNING "mesh: target %d aborted\n",
+			       ms->conn_tgt);
+			dumplog(ms, ms->conn_tgt);
+			dumpslog(ms);
+		}
+		out_8(&mr->interrupt, INT_CMDDONE);
+		ms->stat = DID_ABORT;
+		mesh_done(ms, 1);
+		return;
+	}
+	if (err & ERR_PARITY) {
+		if (ms->msgphase == msg_in) {
+			printk(KERN_ERR "mesh: msg parity error, target %d\n",
+			       ms->conn_tgt);
+			ms->msgout[0] = MSG_PARITY_ERROR;
+			ms->n_msgout = 1;
+			ms->msgphase = msg_in_bad;
+			cmd_complete(ms);
+			return;
+		}
+		if (ms->stat == DID_OK) {
+			printk(KERN_ERR "mesh: parity error, target %d\n",
+			       ms->conn_tgt);
+			ms->stat = DID_PARITY;
+		}
+		count = (mr->count_hi << 8) + mr->count_lo;
+		if (count == 0) {
+			cmd_complete(ms);
+		} else {
+			/* reissue the data transfer command */
+			out_8(&mr->sequence, mr->sequence);
+		}
+		return;
+	}
+	if (err & ERR_SEQERR) {
+		if (exc & EXC_RESELECTED) {
+			/* This can happen if we issue a command to
+			   get the bus just after the target reselects us. */
+			static int mesh_resel_seqerr;
+			mesh_resel_seqerr++;
+			reselected(ms);
+			return;
+		}
+		if (exc == EXC_PHASEMM) {
+			static int mesh_phasemm_seqerr;
+			mesh_phasemm_seqerr++;
+			phase_mismatch(ms);
+			return;
+		}
+		printk(KERN_ERR "mesh: sequence error (err=%x exc=%x)\n",
+		       err, exc);
+	} else {
+		printk(KERN_ERR "mesh: unknown error %x (exc=%x)\n", err, exc);
+	}
+	mesh_dump_regs(ms);
+	dumplog(ms, ms->conn_tgt);
+	if (ms->phase > selecting && (mr->bus_status1 & BS1_BSY)) {
+		/* try to do what the target wants */
+		do_abort(ms);
+		phase_mismatch(ms);
+		return;
+	}
+	ms->stat = DID_ERROR;
+	mesh_done(ms, 1);
+}
+
+static void handle_exception(struct mesh_state *ms)
+{
+	int exc;
+	volatile struct mesh_regs *mr = ms->mesh;
+
+	exc = in_8(&mr->exception);
+	out_8(&mr->interrupt, INT_EXCEPTION | INT_CMDDONE);
+	if (exc & EXC_RESELECTED) {
+		static int mesh_resel_exc;
+		mesh_resel_exc++;
+		reselected(ms);
+	} else if (exc == EXC_ARBLOST) {
+		printk(KERN_DEBUG "mesh: lost arbitration\n");
+		ms->stat = DID_BUS_BUSY;
+		mesh_done(ms, 1);
+	} else if (exc == EXC_SELTO) {
+		/* selection timed out */
+		ms->stat = DID_BAD_TARGET;
+		mesh_done(ms, 1);
+	} else if (exc == EXC_PHASEMM) {
+		/* target wants to do something different:
+		   find out what it wants and do it. */
+		phase_mismatch(ms);
+	} else {
+		printk(KERN_ERR "mesh: can't cope with exception %x\n", exc);
+		mesh_dump_regs(ms);
+		dumplog(ms, ms->conn_tgt);
+		do_abort(ms);
+		phase_mismatch(ms);
+	}
+}
+
 static void
 mesh_interrupt(int irq, void *dev_id, struct pt_regs *ptregs)
 {
 	struct mesh_state *ms = (struct mesh_state *) dev_id;
 	volatile struct mesh_regs *mr = ms->mesh;
-	Scsi_Cmnd *cmd = ms->current_req;
-	int stat, exc, err, intr;
+	int intr;
 
 #if 0
-	if (DEBUG_TARGET(cmd))
-		printk(KERN_DEBUG "mesh_intr, bs0=%x int=%x exc=%x err=%x phase=%d msgphase=%d\n",
-		       mr->bus_status0, mr->interrupt, mr->exception, mr->error, ms->phase, ms->msgphase);
+	if (ALLOW_DEBUG(ms->conn_tgt))
+		printk(KERN_DEBUG "mesh_intr, bs0=%x int=%x exc=%x err=%x "
+		       "phase=%d msgphase=%d\n", mr->bus_status0,
+		       mr->interrupt, mr->exception, mr->error,
+		       ms->phase, ms->msgphase);
 #endif
 	while ((intr = in_8(&mr->interrupt)) != 0) {
+		dlog(ms, "interrupt intr/err/exc/seq=%.8x", 
+		     MKWORD(intr, mr->error, mr->exception, mr->sequence));
 		if (intr & INT_ERROR) {
-			stat = DID_BAD_INTR << 16;
-			err = in_8(&mr->error);
-			exc = in_8(&mr->exception);
-			out_8(&mr->interrupt, INT_ERROR | INT_EXCEPTION | INT_CMDDONE);
-			if (err & ERR_SCSIRESET) {
-				/* SCSI bus was reset */
-				printk(KERN_INFO "mesh: SCSI bus reset detected: "
-				       "waiting for end...");
-				while ((mr->bus_status1 & BS1_RST) != 0)
-					udelay(1);
-				printk("done\n");
-				handle_reset(ms);
-				/* request_q is empty, no point in mesh_start() */
-				continue;
-			} else if (err & ERR_UNEXPDISC) {
-				/* Unexpected disconnect */
-				printk(KERN_WARNING "mesh: target %d aborted\n",
-				       ms->conn_tgt);
-				stat = DID_ABORT << 16;
-			} else if (err & ERR_PARITY) {
-				printk(KERN_ERR "mesh: parity error\n");
-				stat = DID_PARITY << 16;
-			} else if ((err & ERR_SEQERR) && (exc & EXC_RESELECTED)
-				   && ms->phase == arbitrating) {
-				/* This can happen if we issue a command to
-				   get the bus just after the target
-				   reselects us. */
-				static int mesh_resel_seqerr;
-				mesh_resel_seqerr++;
-				reselected(ms);
-				continue;
-			} else {
-				printk(KERN_ERR "mesh: error %x (exc = %x)\n",
-				       err, exc);
-				mesh_dump_regs(ms);
-			}
-			if (cmd != 0) {
-				cmd->result = stat;
-				mesh_done(ms);
-			}
-
+			handle_error(ms);
 		} else if (intr & INT_EXCEPTION) {
-			exc = in_8(&mr->exception);
-			out_8(&mr->interrupt, INT_EXCEPTION | INT_CMDDONE);
-			if (exc & EXC_RESELECTED) {
-				static int mesh_resel_exc;
-				mesh_resel_exc++;
-				reselected(ms);
-			} else if (cmd && exc == EXC_ARBLOST
-				   && ms->phase == arbitrating) {
-				printk(KERN_DEBUG "mesh: lost arbitration\n");
-				cmd->result = DID_BUS_BUSY << 16;
-				mesh_done(ms);
-			} else if (cmd && exc == EXC_SELTO && ms->phase == selecting) {
-				/* selection timed out */
-				cmd->result = DID_BAD_TARGET << 16;
-				mesh_done(ms);
-			} else if (cmd && exc == EXC_PHASEMM
-				   && (mr->bus_status0 & BS0_REQ) != 0) {
-				/* target wants to do something different:
-			   find out what it wants and do it. */
-				phase_mismatch(ms);
-			} else {
-				printk(KERN_ERR "mesh: can't cope with exception %x\n",
-				       exc);
-				cmd->result = DID_ERROR << 16;
-				mesh_done(ms);
-			}
-
+			handle_exception(ms);
 		} else if (intr & INT_CMDDONE) {
 			out_8(&mr->interrupt, INT_CMDDONE);
 			cmd_complete(ms);
@@ -1081,26 +1477,29 @@
 static void
 handle_msgin(struct mesh_state *ms)
 {
-	int i;
+	int i, code;
 	Scsi_Cmnd *cmd = ms->current_req;
 	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
 
 	if (ms->n_msgin == 0)
 		return;
-	if (DEBUG_TARGET(cmd)) {
+	code = ms->msgin[0];
+	if (ALLOW_DEBUG(ms->conn_tgt)) {
 		printk(KERN_DEBUG "got %d message bytes:", ms->n_msgin);
 		for (i = 0; i < ms->n_msgin; ++i)
 			printk(" %x", ms->msgin[i]);
 		printk("\n");
 	}
+	dlog(ms, "msgin msg=%.8x",
+	     MKWORD(ms->n_msgin, code, ms->msgin[1], ms->msgin[2]));
 
 	ms->expect_reply = 0;
 	ms->n_msgout = 0;
 	if (ms->n_msgin < msgin_length(ms))
 		goto reject;
 	if (cmd)
-		cmd->SCp.Message = ms->msgin[0];
-	switch (ms->msgin[0]) {
+		cmd->SCp.Message = code;
+	switch (code) {
 	case COMMAND_COMPLETE:
 		break;
 	case EXTENDED_MESSAGE:
@@ -1136,8 +1535,6 @@
 		ms->data_ptr = tp->saved_ptr;
 		break;
 	case DISCONNECT:
-		tp->phase = ms->phase;
-		tp->data_goes_out = ms->data_goes_out;
 		ms->phase = disconnecting;
 		break;
 	case ABORT:
@@ -1149,14 +1546,16 @@
 	case NOP:
 		break;
 	default:
-		if (cmd && IDENTIFY_BASE <= ms->msgin[0]
-		    && ms->msgin[0] <= IDENTIFY_BASE + 7) {
-			i = ms->msgin[0] - IDENTIFY_BASE;
-			if (i != cmd->lun)
+		if (IDENTIFY_BASE <= code && code <= IDENTIFY_BASE + 7) {
+			if (cmd == NULL) {
+				do_abort(ms);
+				ms->msgphase = msg_out;
+			} else if (code != cmd->lun + IDENTIFY_BASE) {
 				printk(KERN_WARNING "mesh: lun mismatch "
 				       "(%d != %d) on reselection from "
 				       "target %d\n", i, cmd->lun,
 				       ms->conn_tgt);
+			}
 			break;
 		}
 		goto reject;
@@ -1164,35 +1563,45 @@
 	return;
 
  reject:
-	printk(KERN_WARNING "mesh: rejecting message %x from target %d\n",
-	       ms->msgin[0], ms->conn_tgt);
+	printk(KERN_WARNING "mesh: rejecting message from target %d:",
+	       ms->conn_tgt);
+	for (i = 0; i < ms->n_msgin; ++i)
+		printk(" %x", ms->msgin[i]);
+	printk("\n");
 	ms->msgout[0] = MESSAGE_REJECT;
 	ms->n_msgout = 1;
 	ms->msgphase = msg_out;
 }
 
 static void
-mesh_done(struct mesh_state *ms)
+mesh_done(struct mesh_state *ms, int start_next)
 {
 	Scsi_Cmnd *cmd;
 	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
 
 	cmd = ms->current_req;
-	if (DEBUG_TARGET(cmd)) {
-		printk(KERN_DEBUG "mesh_done: result = %x, data_ptr=%d, buflen=%d\n",
-		       cmd->result, ms->data_ptr, cmd->request_bufflen);
-		if ((cmd->cmnd[0] == 0 || cmd->cmnd[0] == 0x12 || cmd->cmnd[0] == 3)
-		    && cmd->request_buffer != 0) {
-			unsigned char *b = cmd->request_buffer;
-			printk(KERN_DEBUG "buffer = %x %x %x %x %x %x %x %x\n",
-			       b[0], b[1], b[2], b[3], b[4], b[5], b[6], b[7]);
+	ms->current_req = 0;
+	tp->current_req = 0;
+	if (cmd) {
+		cmd->result = (ms->stat << 16) + cmd->SCp.Status;
+		if (ms->stat == DID_OK)
+			cmd->result += (cmd->SCp.Message << 8);
+		if (DEBUG_TARGET(cmd)) {
+			printk(KERN_DEBUG "mesh_done: result = %x, data_ptr=%d, buflen=%d\n",
+			       cmd->result, ms->data_ptr, cmd->request_bufflen);
+			if ((cmd->cmnd[0] == 0 || cmd->cmnd[0] == 0x12 || cmd->cmnd[0] == 3)
+			    && cmd->request_buffer != 0) {
+				unsigned char *b = cmd->request_buffer;
+				printk(KERN_DEBUG "buffer = %x %x %x %x %x %x %x %x\n",
+				       b[0], b[1], b[2], b[3], b[4], b[5], b[6], b[7]);
+			}
 		}
+		cmd->SCp.this_residual -= ms->data_ptr;
+		mesh_completed(ms, cmd);
 	}
-	tp->current_req = 0;
-	cmd->SCp.this_residual -= ms->data_ptr;
-	ms->current_req = NULL;
-	mesh_completed(ms, cmd);
-	if (ms->phase != reselecting) {
+	if (start_next) {
+		out_8(&ms->mesh->sequence, SEQ_ENBRESEL);
+		udelay(1);
 		ms->phase = idle;
 		mesh_start(ms);
 	}
@@ -1221,51 +1630,49 @@
 	struct scatterlist *scl;
 	struct dbdma_cmd *dcmds;
 
-	dma_cmd = ms->data_goes_out? OUTPUT_MORE: INPUT_MORE;
+	dma_cmd = ms->tgts[ms->conn_tgt].data_goes_out?
+		OUTPUT_MORE: INPUT_MORE;
 	dcmds = ms->dma_cmds;
 	dtot = 0;
-	cmd->SCp.this_residual = cmd->request_bufflen;
-	if (cmd->use_sg > 0) {
-		total = 0;
-		scl = (struct scatterlist *) cmd->buffer;
-		off = ms->data_ptr;
-		for (i = 0; i < cmd->use_sg; ++i, ++scl) {
-			total += scl->length;
-			if (off >= scl->length) {
-				off -= scl->length;
-				continue;
+	if (cmd) {
+		cmd->SCp.this_residual = cmd->request_bufflen;
+		if (cmd->use_sg > 0) {
+			total = 0;
+			scl = (struct scatterlist *) cmd->buffer;
+			off = ms->data_ptr;
+			for (i = 0; i < cmd->use_sg; ++i, ++scl) {
+				total += scl->length;
+				if (off >= scl->length) {
+					off -= scl->length;
+					continue;
+				}
+				if (scl->length > 0xffff)
+					panic("mesh: scatterlist element >= 64k");
+				st_le16(&dcmds->req_count, scl->length - off);
+				st_le16(&dcmds->command, dma_cmd);
+				st_le32(&dcmds->phy_addr,
+					virt_to_phys(scl->address) + off);
+				dcmds->xfer_status = 0;
+				++dcmds;
+				dtot += scl->length - off;
+				off = 0;
 			}
-			if (scl->length > 0xffff)
-				panic("mesh: scatterlist element >= 64k");
-			st_le16(&dcmds->req_count, scl->length - off);
-			st_le16(&dcmds->command, dma_cmd);
+		} else if (ms->data_ptr < cmd->request_bufflen) {
+			dtot = cmd->request_bufflen - ms->data_ptr;
+			if (dtot > 0xffff)
+				panic("mesh: transfer size >= 64k");
+			st_le16(&dcmds->req_count, dtot);
 			st_le32(&dcmds->phy_addr,
-				virt_to_phys(scl->address) + off);
+				virt_to_phys(cmd->request_buffer) + ms->data_ptr);
 			dcmds->xfer_status = 0;
 			++dcmds;
-			dtot += scl->length - off;
-			off = 0;
 		}
-	} else if (ms->data_ptr < cmd->request_bufflen) {
-		dtot = cmd->request_bufflen - ms->data_ptr;
-		if (dtot > 0xffff)
-			panic("mesh: transfer size >= 64k");
-		st_le16(&dcmds->req_count, dtot);
-		st_le32(&dcmds->phy_addr,
-			virt_to_phys(cmd->request_buffer) + ms->data_ptr);
-		dcmds->xfer_status = 0;
-		++dcmds;
 	}
 	if (dtot == 0) {
 		/* Either the target has overrun our buffer,
 		   or the caller didn't provide a buffer. */
 		static char mesh_extra_buf[64];
 
-		if (cmd->request_bufflen != 0)
-			printk(KERN_DEBUG "mesh: target %d overrun, "
-			       "data_ptr=%x total=%x goes_out=%d\n",
-			       ms->conn_tgt, ms->data_ptr,
-			       cmd->request_bufflen, ms->data_goes_out);
 		dtot = sizeof(mesh_extra_buf);
 		st_le16(&dcmds->req_count, dtot);
 		st_le32(&dcmds->phy_addr, virt_to_phys(mesh_extra_buf));
@@ -1284,9 +1691,10 @@
 {
 	volatile struct dbdma_regs *md = ms->dma;
 	volatile struct mesh_regs *mr = ms->mesh;
+	Scsi_Cmnd *cmd = ms->current_req;
 	int t, nb;
 
-	if (!ms->data_goes_out) {
+	if (!ms->tgts[ms->conn_tgt].data_goes_out) {
 		/* wait a little while until the fifo drains */
 		t = 50;
 		while (t > 0 && mr->fifo_count != 0
@@ -1297,15 +1705,28 @@
 	}
 	out_le32(&md->control, RUN << 16);	/* turn off RUN bit */
 	nb = (mr->count_hi << 8) + mr->count_lo;
-	if (ms->data_goes_out)
+	dlog(ms, "halt_dma fc/count=%.6x",
+	     MKWORD(0, mr->fifo_count, 0, nb));
+	if (ms->tgts[ms->conn_tgt].data_goes_out)
 		nb += mr->fifo_count;
 	/* nb is the number of bytes not yet transferred
 	   to/from the target. */
 	ms->data_ptr -= nb;
+	dlog(ms, "data_ptr %x", ms->data_ptr);
 	if (ms->data_ptr < 0) {
 		printk(KERN_ERR "mesh: halt_dma: data_ptr=%d (nb=%d, ms=%p)\n",
 		       ms->data_ptr, nb, ms);
 		ms->data_ptr = 0;
+#ifdef MESH_DBG
+		dumplog(ms, ms->conn_tgt);
+		dumpslog(ms);
+#endif /* MESH_DBG */
+	} else if (cmd && cmd->request_bufflen != 0 &&
+		   ms->data_ptr > cmd->request_bufflen) {
+		printk(KERN_DEBUG "mesh: target %d overrun, "
+		       "data_ptr=%x total=%x goes_out=%d\n",
+		       ms->conn_tgt, ms->data_ptr, cmd->request_bufflen,
+		       ms->tgts[ms->conn_tgt].data_goes_out);
 	}
 	ms->dma_started = 0;
 }
@@ -1319,13 +1740,129 @@
 data_goes_out(Scsi_Cmnd *cmd)
 {
 	switch (cmd->cmnd[0]) {
+	case CHANGE_DEFINITION: 
+	case COMPARE:	  
+	case COPY:
+	case COPY_VERIFY:	    
+	case FORMAT_UNIT:	 
+	case LOG_SELECT:
+	case MEDIUM_SCAN:	  
 	case MODE_SELECT:
 	case MODE_SELECT_10:
-	case WRITE_6:
-	case WRITE_10:
-	case WRITE_12:		/* any others? */
+	case REASSIGN_BLOCKS: 
+	case RESERVE:
+	case SEARCH_EQUAL:	  
+	case SEARCH_EQUAL_12: 
+	case SEARCH_HIGH:	 
+	case SEARCH_HIGH_12:  
+	case SEARCH_LOW:
+	case SEARCH_LOW_12:
+	case SEND_DIAGNOSTIC: 
+	case SEND_VOLUME_TAG:	     
+	case SET_WINDOW: 
+	case UPDATE_BLOCK:	
+	case WRITE_BUFFER:
+ 	case WRITE_6:	
+	case WRITE_10:	
+	case WRITE_12:	  
+	case WRITE_LONG:	
+	case WRITE_LONG_2:      /* alternate code for WRITE_LONG */
+	case WRITE_SAME:	
+	case WRITE_VERIFY:
+	case WRITE_VERIFY_12:
 		return 1;
 	default:
 		return 0;
 	}
 }
+
+#ifdef MESH_DBG
+static inline u32 readtb(void)
+{
+	u32 tb;
+
+#ifdef DBG_USE_TB
+	/* Beware: if you enable this, it will crash on 601s. */
+	asm ("mftb %0" : "=r" (tb) : );
+#else
+	tb = 0;
+#endif
+	return tb;
+}
+
+static void dlog(struct mesh_state *ms, char *fmt, int a)
+{
+	struct mesh_target *tp = &ms->tgts[ms->conn_tgt];
+	struct dbglog *tlp, *slp;
+
+	tlp = &tp->log[tp->log_ix];
+	slp = &ms->log[ms->log_ix];
+	tlp->fmt = fmt;
+	tlp->tb = readtb();
+	tlp->phase = (ms->msgphase << 4) + ms->phase;
+	tlp->bs0 = ms->mesh->bus_status0;
+	tlp->bs1 = ms->mesh->bus_status1;
+	tlp->tgt = ms->conn_tgt;
+	tlp->d = a;
+	*slp = *tlp;
+	if (++tp->log_ix >= N_DBG_LOG)
+		tp->log_ix = 0;
+	if (tp->n_log < N_DBG_LOG)
+		++tp->n_log;
+	if (++ms->log_ix >= N_DBG_SLOG)
+		ms->log_ix = 0;
+	if (ms->n_log < N_DBG_SLOG)
+		++ms->n_log;
+}
+
+static void dumplog(struct mesh_state *ms, int t)
+{
+	struct mesh_target *tp = &ms->tgts[t];
+	struct dbglog *lp;
+	int i;
+
+	if (tp->n_log == 0)
+		return;
+	i = tp->log_ix - tp->n_log;
+	if (i < 0)
+		i += N_DBG_LOG;
+	tp->n_log = 0;
+	do {
+		lp = &tp->log[i];
+		printk(KERN_DEBUG "mesh log %d: bs=%.2x%.2x ph=%.2x ",
+		       t, lp->bs1, lp->bs0, lp->phase);
+#ifdef DBG_USE_TB
+		printk("tb=%10u ", lp->tb);
+#endif
+		printk(lp->fmt, lp->d);
+		printk("\n");
+		if (++i >= N_DBG_LOG)
+			i = 0;
+	} while (i != tp->log_ix);
+}
+
+static void dumpslog(struct mesh_state *ms)
+{
+	struct dbglog *lp;
+	int i;
+
+	if (ms->n_log == 0)
+		return;
+	i = ms->log_ix - ms->n_log;
+	if (i < 0)
+		i += N_DBG_SLOG;
+	ms->n_log = 0;
+	do {
+		lp = &ms->log[i];
+		printk(KERN_DEBUG "mesh log: bs=%.2x%.2x ph=%.2x t%d ",
+		       lp->bs1, lp->bs0, lp->phase, lp->tgt);
+#ifdef DBG_USE_TB
+		printk("tb=%10u ", lp->tb);
+#endif
+		printk(lp->fmt, lp->d);
+		printk("\n");
+		if (++i >= N_DBG_SLOG)
+			i = 0;
+	} while (i != ms->log_ix);
+}
+#endif /* MESH_DBG */