UAS uses a shared tag space. We reserve tag #1 for management.
That leaves us with an offset of 2.
Signed-off-by: Oliver Neukum <oneu...@suse.com>
---
drivers/usb/storage/uas.c | 32 ++++++++++++++++++++++++--------
1 file changed, 24 insertions(+), 8 deletions(-)
diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c
index 13e6313..a8052ec 100644
--- a/drivers/usb/storage/uas.c
+++ b/drivers/usb/storage/uas.c
@@ -32,6 +32,12 @@
#define MAX_CMNDS 256
+/*
+ * 1 is due to the different base
+ * and 1 is reserved for the tmf
+ */
+#define TAG_OFFSET (1 + 1)
+
struct uas_dev_info {
struct usb_interface *intf;
struct usb_device *udev;
@@ -97,7 +103,7 @@ static void uas_do_work(struct work_struct *work)
if (devinfo->resetting)
goto out;
- for (i = 0; i < devinfo->qdepth; i++) {
+ for (i = 0; i < devinfo->qdepth - 1; i++) {
if (!devinfo->cmnd[i])
continue;
@@ -229,7 +235,7 @@ static int uas_try_complete(struct scsi_cmnd *cmnd, const
char *caller)
DATA_OUT_URB_INFLIGHT |
COMMAND_ABORTED))
return -EBUSY;
- devinfo->cmnd[cmdinfo->uas_tag - 1] = NULL;
+ devinfo->cmnd[cmdinfo->uas_tag - TAG_OFFSET] = NULL;
uas_free_unsubmitted_urbs(cmnd);
cmnd->scsi_done(cmnd);
return 0;
@@ -296,10 +302,10 @@ static void uas_stat_cmplt(struct urb *urb)
goto out;
}
- idx = be16_to_cpup(&iu->tag) - 1;
+ idx = be16_to_cpup(&iu->tag) - TAG_OFFSET;
if (idx >= MAX_CMNDS || !devinfo->cmnd[idx]) {
dev_err(&urb->dev->dev,
- "stat urb: no pending cmd for uas-tag %d\n", idx + 1);
+ "stat urb: no pending cmd for uas-tag %d\n", idx +
TAG_OFFSET);
goto out;
}
@@ -653,7 +659,7 @@ static int uas_queuecommand_lck(struct scsi_cmnd *cmnd,
if (!devinfo->cmnd[idx])
break;
}
- if (idx == devinfo->qdepth) {
+ if (idx >= devinfo->qdepth - 1) {
spin_unlock_irqrestore(&devinfo->lock, flags);
return SCSI_MLQUEUE_DEVICE_BUSY;
}
@@ -661,7 +667,11 @@ static int uas_queuecommand_lck(struct scsi_cmnd *cmnd,
cmnd->scsi_done = done;
memset(cmdinfo, 0, sizeof(*cmdinfo));
- cmdinfo->uas_tag = idx + 1; /* uas-tag == usb-stream-id, so 1 based */
+ cmdinfo->uas_tag = idx + TAG_OFFSET;
+ /*
+ * uas-tag == usb-stream-id, so 1 based
+ * and 1 reserved for management
+ */
cmdinfo->state = SUBMIT_STATUS_URB | ALLOC_CMD_URB | SUBMIT_CMD_URB;
switch (cmnd->sc_data_direction) {
@@ -717,7 +727,7 @@ static int uas_eh_abort_handler(struct scsi_cmnd *cmnd)
cmdinfo->state |= COMMAND_ABORTED;
/* Drop all refs to this cmnd, kill data urbs to break their ref */
- devinfo->cmnd[cmdinfo->uas_tag - 1] = NULL;
+ devinfo->cmnd[cmdinfo->uas_tag - TAG_OFFSET] = NULL;
if (cmdinfo->state & DATA_IN_URB_INFLIGHT)
data_in_urb = usb_get_urb(cmdinfo->data_in_urb);
if (cmdinfo->state & DATA_OUT_URB_INFLIGHT)
@@ -826,7 +836,13 @@ static int uas_slave_configure(struct scsi_device *sdev)
if (devinfo->flags & US_FL_BROKEN_FUA)
sdev->broken_fua = 1;
- scsi_change_queue_depth(sdev, devinfo->qdepth - 2);
+ /*
+ * We take three slots, one each for
+ * - untagged commands
+ * - guarding against firmware bugs about the indexing
+ * - the TMF tag
+ */
+ scsi_change_queue_depth(sdev, devinfo->qdepth - 3);
return 0;
}
--
2.1.4
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