[SCSI] hpsa: do readl after writel in main i/o path to ensure commands don't get lost.
Apparently we've been doin it rong for a decade, but only lately do we
run into problems.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <jbottomley@parallels.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
diff --git a/drivers/scsi/hpsa.h b/drivers/scsi/hpsa.h
index 621a153..98c97ca 100644
--- a/drivers/scsi/hpsa.h
+++ b/drivers/scsi/hpsa.h
@@ -212,6 +212,7 @@
dev_dbg(&h->pdev->dev, "Sending %x, tag = %x\n", c->busaddr,
c->Header.Tag.lower);
writel(c->busaddr, h->vaddr + SA5_REQUEST_PORT_OFFSET);
+ (void) readl(h->vaddr + SA5_REQUEST_PORT_OFFSET);
h->commands_outstanding++;
if (h->commands_outstanding > h->max_outstanding)
h->max_outstanding = h->commands_outstanding;