Patch to fix ub looping with a tag mismatch
From: Pete Zaitcev
Date: Sat Jan 08 2005 - 00:24:14 EST
If a command times out, we resubmit a retry. Some devices, however, buffer
everything we send and then eventually reply to a command we have timed out
already. We receive a bad tag, send a new command, device replies to the
one sent before, and so on without end.
The fix is to flush pending replies if tags mismatch (by reading them).
Signed-off-by: Pete Zaitcev
diff -urp -X dontdiff linux-2.6.10/drivers/block/ub.c linux-2.6.10-ub/drivers/block/ub.c
--- linux-2.6.10/drivers/block/ub.c 2005-01-05 00:37:35.000000000 -0800
+++ linux-2.6.10-ub/drivers/block/ub.c 2005-01-07 21:10:12.901318978 -0800
@@ -108,7 +108,8 @@ struct ub_dev;
*/
#define UB_URB_TIMEOUT (HZ*2)
#define UB_DATA_TIMEOUT (HZ*5) /* ZIP does spin-ups in the data phase */
-#define UB_CTRL_TIMEOUT (HZ/2) /* 500ms ought to be enough to clear a stall */
+#define UB_STAT_TIMEOUT (HZ*5) /* Same spinups and eject for a dataless cmd. */
+#define UB_CTRL_TIMEOUT (HZ/2) /* 500ms ought to be enough to clear a stall */
/*
* An instance of a SCSI command in transit.
@@ -307,6 +308,7 @@ static void ub_scsi_action(unsigned long
static void ub_scsi_dispatch(struct ub_dev *sc);
static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
static void ub_state_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd, int rc);
+static void __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
static void ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
static void ub_state_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
static int ub_submit_clear_stall(struct ub_dev *sc, struct ub_scsi_cmd *cmd,
@@ -894,7 +896,7 @@ static void ub_scsi_urb_compl(struct ub_
if (urb->status == -EPIPE) {
/*
* STALL while clearning STALL.
- * A STALL is illegal on a control pipe!
+ * The control pipe clears itself - nothing to do.
* XXX Might try to reset the device here and retry.
*/
printk(KERN_NOTICE "%s: "
@@ -917,7 +919,7 @@ static void ub_scsi_urb_compl(struct ub_
if (urb->status == -EPIPE) {
/*
* STALL while clearning STALL.
- * A STALL is illegal on a control pipe!
+ * The control pipe clears itself - nothing to do.
* XXX Might try to reset the device here and retry.
*/
printk(KERN_NOTICE "%s: "
@@ -941,7 +943,8 @@ static void ub_scsi_urb_compl(struct ub_
rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe);
if (rc != 0) {
printk(KERN_NOTICE "%s: "
- "unable to submit clear for device %u (%d)\n",
+ "unable to submit clear for device %u"
+ " (code %d)\n",
sc->name, sc->dev->devnum, rc);
/*
* This is typically ENOMEM or some other such shit.
@@ -1001,7 +1004,8 @@ static void ub_scsi_urb_compl(struct ub_
rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe);
if (rc != 0) {
printk(KERN_NOTICE "%s: "
- "unable to submit clear for device %u (%d)\n",
+ "unable to submit clear for device %u"
+ " (code %d)\n",
sc->name, sc->dev->devnum, rc);
/*
* This is typically ENOMEM or some other such shit.
@@ -1033,7 +1037,8 @@ static void ub_scsi_urb_compl(struct ub_
rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe);
if (rc != 0) {
printk(KERN_NOTICE "%s: "
- "unable to submit clear for device %u (%d)\n",
+ "unable to submit clear for device %u"
+ " (code %d)\n",
sc->name, sc->dev->devnum, rc);
/*
* This is typically ENOMEM or some other such shit.
@@ -1061,33 +1066,7 @@ static void ub_scsi_urb_compl(struct ub_
sc->name, sc->dev->devnum);
goto Bad_End;
}
-
- /*
- * ub_state_stat only not dropping the count...
- */
- UB_INIT_COMPLETION(sc->work_done);
-
- sc->last_pipe = sc->recv_bulk_pipe;
- usb_fill_bulk_urb(&sc->work_urb, sc->dev,
- sc->recv_bulk_pipe, &sc->work_bcs,
- US_BULK_CS_WRAP_LEN, ub_urb_complete, sc);
- sc->work_urb.transfer_flags = URB_ASYNC_UNLINK;
- sc->work_urb.actual_length = 0;
- sc->work_urb.error_count = 0;
- sc->work_urb.status = 0;
-
- rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC);
- if (rc != 0) {
- /* XXX Clear stalls */
- printk("%s: CSW #%d submit failed (%d)\n",
- sc->name, cmd->tag, rc); /* P3 */
- ub_complete(&sc->work_done);
- ub_state_done(sc, cmd, rc);
- return;
- }
-
- sc->work_timer.expires = jiffies + UB_URB_TIMEOUT;
- add_timer(&sc->work_timer);
+ __ub_state_stat(sc, cmd);
return;
}
@@ -1108,17 +1087,31 @@ static void ub_scsi_urb_compl(struct ub_
goto Bad_End;
}
+#if 0
if (bcs->Signature != cpu_to_le32(US_BULK_CS_SIGN) &&
bcs->Signature != cpu_to_le32(US_BULK_CS_OLYMPUS_SIGN)) {
- /* XXX Rate-limit, even for P3 tagged */
- /* P3 */ printk("ub: signature 0x%x\n", bcs->Signature);
/* Windows ignores signatures, so do we. */
}
+#endif
if (bcs->Tag != cmd->tag) {
- /* P3 */ printk("%s: tag orig 0x%x reply 0x%x\n",
- sc->name, cmd->tag, bcs->Tag);
- goto Bad_End;
+ /*
+ * This usually happens when we disagree with the
+ * device's microcode about something. For instance,
+ * a few of them throw this after timeouts. They buffer
+ * commands and reply at commands we timed out before.
+ * Without flushing these replies we loop forever.
+ */
+ if (++cmd->stat_count >= 4) {
+ printk(KERN_NOTICE "%s: "
+ "tag mismatch orig 0x%x reply 0x%x "
+ "on device %u\n",
+ sc->name, cmd->tag, bcs->Tag,
+ sc->dev->devnum);
+ goto Bad_End;
+ }
+ __ub_state_stat(sc, cmd);
+ return;
}
switch (bcs->Status) {
@@ -1174,9 +1167,9 @@ static void ub_state_done(struct ub_dev
/*
* Factorization helper for the command state machine:
- * Submit a CSW read and go to STAT state.
+ * Submit a CSW read.
*/
-static void ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
+static void __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
{
int rc;
@@ -1192,14 +1185,23 @@ static void ub_state_stat(struct ub_dev
if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
/* XXX Clear stalls */
- printk("ub: CSW #%d submit failed (%d)\n", cmd->tag, rc); /* P3 */
+ printk("%s: CSW #%d submit failed (%d)\n", sc->name, cmd->tag, rc); /* P3 */
ub_complete(&sc->work_done);
ub_state_done(sc, cmd, rc);
return;
}
- sc->work_timer.expires = jiffies + UB_URB_TIMEOUT;
+ sc->work_timer.expires = jiffies + UB_STAT_TIMEOUT;
add_timer(&sc->work_timer);
+}
+
+/*
+ * Factorization helper for the command state machine:
+ * Submit a CSW read and go to STAT state.
+ */
+static void ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
+{
+ __ub_state_stat(sc, cmd);
cmd->stat_count = 0;
cmd->state = UB_CMDST_STAT;
-
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