[SCSI] mac_esp: fix PIO mode, take 2

The mac_esp PIO algorithm no longer works in 2.6.31 and crashes my Centris
660av. So here's a better one.

Also, force async with esp_set_offset() rather than esp_slave_configure().

One of the SCSI drives I tested still doesn't like the PIO mode and fails
with "esp: esp0: Reconnect IRQ2 timeout" (the same drive works fine in
PDMA mode).

This failure happens when esp_reconnect_with_tag() tries to read in two
tag bytes but the chip only provides one (0x20). I don't know what causes
this. I decided not to waste any more time trying to fix it because the
best solution is to rip out the PIO mode altogether and use the DMA
engine.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

1 files changed, 4 insertions, 10 deletions

diff --git a/drivers/scsi/esp_scsi.c b/drivers/scsi/esp_scsi.c
index a680e18b5f3b..e2bc779f86c1 100644
--- a/drivers/scsi/esp_scsi.c
+++ b/drivers/scsi/esp_scsi.c
@@ -1449,9 +1449,6 @@ static void esp_msgin_sdtr(struct esp *esp, struct esp_target_data *tp)
         if (offset > 15)
                 goto do_reject;
 
-        if (esp->flags & ESP_FLAG_DISABLE_SYNC)
-                offset = 0;
-
         if (offset) {
                 int one_clock;
 
@@ -2405,12 +2402,6 @@ static int esp_slave_configure(struct scsi_device *dev)
         struct esp_target_data *tp = &esp->target[dev->id];
         int goal_tags, queue_depth;
 
-        if (esp->flags & ESP_FLAG_DISABLE_SYNC) {
-                /* Bypass async domain validation */
-                dev->ppr  = 0;
-                dev->sdtr = 0;
-        }
-
         goal_tags = 0;
 
         if (dev->tagged_supported) {
@@ -2660,7 +2651,10 @@ static void esp_set_offset(struct scsi_target *target, int offset)
         struct esp *esp = shost_priv(host);
         struct esp_target_data *tp = &esp->target[target->id];
 
-        tp->nego_goal_offset = offset;
+        if (esp->flags & ESP_FLAG_DISABLE_SYNC)
+                tp->nego_goal_offset = 0;
+        else
+                tp->nego_goal_offset = offset;
         tp->flags |= ESP_TGT_CHECK_NEGO;
 }