[SCSI] hpsa: prevent stalled i/o
If a fifo full condition is encountered, i/o requests will stack
up in the h->reqQ queue. The only thing which empties this queue
is start_io, which only gets called when new i/o requests come in.
If none are forthcoming, i/o in h->reqQ will be stalled.
To fix this, whenever fifo full condition is encountered, this
is recorded, and the interrupt handler examines this to see
if a fifo full condition was recently encountered when a
command completes and will call start_io to prevent i/o's in
h->reqQ from getting stuck.
I've only ever seen this problem occur when running specialized
test programs that pound on the the CCISS_PASSTHRU ioctl.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/drivers/scsi/hpsa.h b/drivers/scsi/hpsa.h
index 6eabf08..5f3f72f 100644
--- a/drivers/scsi/hpsa.h
+++ b/drivers/scsi/hpsa.h
@@ -136,6 +136,7 @@
atomic_t firmware_flash_in_progress;
u32 lockup_detected;
struct list_head lockup_list;
+ u32 fifo_recently_full;
/* Address of h->q[x] is passed to intr handler to know which queue */
u8 q[MAX_REPLY_QUEUES];
u32 TMFSupportFlags; /* cache what task mgmt funcs are supported. */