[PATCH v2 43/72] ncr5380: Standardize reselection handling

Finn Thain
2015-12-06T01:32:09Z

[-- Attachment #1: ncr5380-standardize-reselection-handling --]
[-- Type: text/plain, Size: 10575 bytes --]

Bring the two NCR5380_reselect() implementations into agreement.

Replace infinite loops in atari_NCR5380.c with timeouts, as per NCR5380.c.

Remove 'abort' flag in NCR5380.c as per atari_NCR5380.c -- if reselection
fails, there may be no MESSAGE IN phase so don't attempt data transfer.

During selection, don't interfere with the chip registers after a
reselection interrupt intervenes.

Clean up some trivial issues with code style, comments and printk.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>

---
drivers/scsi/NCR5380.c | 115 +++++++++++++++++++++++--------------------
drivers/scsi/atari_NCR5380.c | 50 ++++++++++--------
2 files changed, 93 insertions(+), 72 deletions(-)

Index: linux/drivers/scsi/NCR5380.c
===================================================================
--- linux.orig/drivers/scsi/NCR5380.c 2015-12-06 12:30:35.000000000 +1100
+++ linux/drivers/scsi/NCR5380.c 2015-12-06 12:30:36.000000000 +1100
@@ -1177,6 +1177,10 @@ static int NCR5380_select(struct Scsi_Ho
else
udelay(2);

+ /* NCR5380_reselect() clears MODE_REG after a reselection interrupt */
+ if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE))
+ return -1;
+
dprintk(NDEBUG_ARBITRATION, "scsi%d : won arbitration\n", instance->host_no);

/*
@@ -1948,12 +1952,14 @@ static void NCR5380_information_transfer
cmd->scsi_done(cmd);
}

- NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
/*
* Restore phase bits to 0 so an interrupted selection,
* arbitration can resume.
*/
NCR5380_write(TARGET_COMMAND_REG, 0);
+
+ /* Enable reselect interrupts */
+ NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
return;
case MESSAGE_REJECT:
/* Accept message by clearing ACK */
@@ -2139,7 +2145,6 @@ static void NCR5380_reselect(struct Scsi
unsigned char msg[3];
unsigned char *data;
struct scsi_cmnd *tmp = NULL, *prev;
- int abort = 0;

/*
* Disable arbitration, etc. since the host adapter obviously
@@ -2149,7 +2154,7 @@ static void NCR5380_reselect(struct Scsi
NCR5380_write(MODE_REG, MR_BASE);

target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
- dprintk(NDEBUG_SELECTION, "scsi%d : reselect\n", instance->host_no);
+ dprintk(NDEBUG_RESELECTION, "scsi%d : reselect\n", instance->host_no);

/*
* At this point, we have detected that our SCSI ID is on the bus,
@@ -2161,77 +2166,85 @@ static void NCR5380_reselect(struct Scsi
*/

NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
-
- /* FIXME: timeout too long, must fail to workqueue */
- if(NCR5380_poll_politely(instance, STATUS_REG, SR_SEL, 0, 2*HZ)<0)
- abort = 1;
-
+ if (NCR5380_poll_politely(instance,
+ STATUS_REG, SR_SEL, 0, 2 * HZ) < 0) {
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+ return;
+ }
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);

/*
* Wait for target to go into MSGIN.
- * FIXME: timeout needed and fail to work queeu
*/

if (NCR5380_poll_politely(instance,
- STATUS_REG, SR_REQ, SR_REQ, 2 * HZ) < 0)
- abort = 1;
+ STATUS_REG, SR_REQ, SR_REQ, 2 * HZ) < 0) {
+ do_abort(instance);
+ return;
+ }

len = 1;
data = msg;
phase = PHASE_MSGIN;
NCR5380_transfer_pio(instance, &phase, &len, &data);

+ if (len) {
+ do_abort(instance);
+ return;
+ }
+
if (!(msg[0] & 0x80)) {
- printk(KERN_ERR "scsi%d : expecting IDENTIFY message, got ", instance->host_no);
+ shost_printk(KERN_ERR, instance, "expecting IDENTIFY message, got ");
spi_print_msg(msg);
- abort = 1;
- } else {
- /* Accept message by clearing ACK */
- NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
- lun = (msg[0] & 0x07);
-
- /*
- * We need to add code for SCSI-II to track which devices have
- * I_T_L_Q nexuses established, and which have simple I_T_L
- * nexuses so we can chose to do additional data transfer.
- */
+ printk("\n");
+ do_abort(instance);
+ return;
+ }
+ lun = msg[0] & 0x07;

- /*
- * Find the command corresponding to the I_T_L or I_T_L_Q nexus we
- * just reestablished, and remove it from the disconnected queue.
- */
+ /*
+ * We need to add code for SCSI-II to track which devices have
+ * I_T_L_Q nexuses established, and which have simple I_T_L
+ * nexuses so we can chose to do additional data transfer.
+ */

+ /*
+ * Find the command corresponding to the I_T_L or I_T_L_Q nexus we
+ * just reestablished, and remove it from the disconnected queue.
+ */

- for (tmp = (struct scsi_cmnd *) hostdata->disconnected_queue, prev = NULL; tmp; prev = tmp, tmp = (struct scsi_cmnd *) tmp->host_scribble)
- if ((target_mask == (1 << tmp->device->id)) && (lun == (u8)tmp->device->lun)
- ) {
- if (prev) {
- REMOVE(prev, prev->host_scribble, tmp, tmp->host_scribble);
- prev->host_scribble = tmp->host_scribble;
- } else {
- REMOVE(-1, hostdata->disconnected_queue, tmp, tmp->host_scribble);
- hostdata->disconnected_queue = (struct scsi_cmnd *) tmp->host_scribble;
- }
- tmp->host_scribble = NULL;
- break;
+ for (tmp = (struct scsi_cmnd *) hostdata->disconnected_queue, prev = NULL;
+ tmp; prev = tmp, tmp = (struct scsi_cmnd *) tmp->host_scribble) {
+ if ((target_mask == (1 << tmp->device->id)) && (lun == (u8)tmp->device->lun)) {
+ if (prev) {
+ REMOVE(prev, prev->host_scribble, tmp, tmp->host_scribble);
+ prev->host_scribble = tmp->host_scribble;
+ } else {
+ REMOVE(-1, hostdata->disconnected_queue, tmp, tmp->host_scribble);
+ hostdata->disconnected_queue =
+ (struct scsi_cmnd *) tmp->host_scribble;
}
- if (!tmp) {
- printk(KERN_ERR "scsi%d : warning : target bitmask %02x lun %d not in disconnect_queue.\n", instance->host_no, target_mask, lun);
- /*
- * Since we have an established nexus that we can't do anything with,
- * we must abort it.
- */
- abort = 1;
+ tmp->host_scribble = NULL;
+ break;
}
}
-
- if (abort) {
+ if (!tmp) {
+ shost_printk(KERN_ERR, instance, "target bitmask 0x%02x lun %d not in disconnected queue.\n",
+ target_mask, lun);
+ /*
+ * Since we have an established nexus that we can't do anything with,
+ * we must abort it.
+ */
do_abort(instance);
- } else {
- hostdata->connected = tmp;
- dprintk(NDEBUG_RESELECTION, "scsi%d : nexus established, target = %d, lun = %llu, tag = %d\n", instance->host_no, tmp->device->id, tmp->device->lun, tmp->tag);
+ return;
}
+
+ /* Accept message by clearing ACK */
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+
+ hostdata->connected = tmp;
+ dprintk(NDEBUG_RESELECTION, "scsi%d : nexus established, target = %d, lun = %llu, tag = %d\n",
+ instance->host_no, tmp->device->id, tmp->device->lun, tmp->tag);
}

/*
Index: linux/drivers/scsi/atari_NCR5380.c
===================================================================
--- linux.orig/drivers/scsi/atari_NCR5380.c 2015-12-06 12:30:32.000000000 +1100
+++ linux/drivers/scsi/atari_NCR5380.c 2015-12-06 12:30:36.000000000 +1100
@@ -1441,11 +1441,9 @@ static int NCR5380_select(struct Scsi_Ho
else
udelay(2);

- if (hostdata->connected) {
- NCR5380_write(MODE_REG, MR_BASE);
- NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+ /* NCR5380_reselect() clears MODE_REG after a reselection interrupt */
+ if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE))
return -1;
- }

dprintk(NDEBUG_ARBITRATION, "scsi%d: won arbitration\n", HOSTNO);

@@ -2218,13 +2216,15 @@ static void NCR5380_information_transfer
cmd->scsi_done(cmd);
}

- NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
/*
* Restore phase bits to 0 so an interrupted selection,
* arbitration can resume.
*/
NCR5380_write(TARGET_COMMAND_REG, 0);

+ /* Enable reselect interrupts */
+ NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
+
/* ++roman: For Falcon SCSI, release the lock on the
* ST-DMA here if no other commands are waiting on the
* disconnected queue.
@@ -2477,17 +2477,22 @@ static void NCR5380_reselect(struct Scsi
*/

NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
-
- while (NCR5380_read(STATUS_REG) & SR_SEL)
- ;
+ if (NCR5380_poll_politely(instance,
+ STATUS_REG, SR_SEL, 0, 2 * HZ) < 0) {
+ NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
+ return;
+ }
NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);

/*
* Wait for target to go into MSGIN.
*/

- while (!(NCR5380_read(STATUS_REG) & SR_REQ))
- ;
+ if (NCR5380_poll_politely(instance,
+ STATUS_REG, SR_REQ, SR_REQ, 2 * HZ) < 0) {
+ do_abort(instance);
+ return;
+ }

#if defined(CONFIG_SUN3) && defined(REAL_DMA)
/* acknowledge toggle to MSGIN */
@@ -2500,15 +2505,21 @@ static void NCR5380_reselect(struct Scsi
data = msg;
phase = PHASE_MSGIN;
NCR5380_transfer_pio(instance, &phase, &len, &data);
+
+ if (len) {
+ do_abort(instance);
+ return;
+ }
#endif

if (!(msg[0] & 0x80)) {
- printk(KERN_DEBUG "scsi%d: expecting IDENTIFY message, got ", HOSTNO);
+ shost_printk(KERN_ERR, instance, "expecting IDENTIFY message, got ");
spi_print_msg(msg);
+ printk("\n");
do_abort(instance);
return;
}
- lun = (msg[0] & 0x07);
+ lun = msg[0] & 0x07;

#if defined(SUPPORT_TAGS) && !defined(CONFIG_SUN3)
/* If the phase is still MSGIN, the target wants to send some more
@@ -2536,7 +2547,7 @@ static void NCR5380_reselect(struct Scsi

for (tmp = (struct scsi_cmnd *) hostdata->disconnected_queue, prev = NULL;
tmp; prev = tmp, tmp = NEXT(tmp)) {
- if ((target_mask == (1 << tmp->device->id)) && (lun == tmp->device->lun)
+ if ((target_mask == (1 << tmp->device->id)) && (lun == (u8)tmp->device->lun)
#ifdef SUPPORT_TAGS
&& (tag == tmp->tag)
#endif
@@ -2554,16 +2565,13 @@ static void NCR5380_reselect(struct Scsi
}

if (!tmp) {
- printk(KERN_WARNING "scsi%d: warning: target bitmask %02x lun %d "
#ifdef SUPPORT_TAGS
- "tag %d "
-#endif
- "not in disconnected_queue.\n",
- HOSTNO, target_mask, lun
-#ifdef SUPPORT_TAGS
- , tag
+ shost_printk(KERN_ERR, instance, "target bitmask 0x%02x lun %d tag %d not in disconnected queue.\n",
+ target_mask, lun, tag);
+#else
+ shost_printk(KERN_ERR, instance, "target bitmask 0x%02x lun %d not in disconnected queue.\n",
+ target_mask, lun);
#endif
- );
/*
* Since we have an established nexus that we can't do anything
* with, we must abort it.