This is a note to let you know that I've just added the patch titled
usb: dwc3: gadget: fix missed isoc
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-next branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
>From 7efea86c2868b8fd9df65e589e33aebe498ce21d Mon Sep 17 00:00:00 2001
From: Pratyush Anand <[email protected]>
Date: Mon, 14 Jan 2013 15:59:32 +0530
Subject: usb: dwc3: gadget: fix missed isoc
There are two reasons to generate missed isoc.
1. when the host does not poll for all the data.
2. because of application-side delays that prevent all the data from
being transferred in programmed microframe.
Current code was able to handle first case only. This patch handles
scenario 2 as well.Scenario 2 sometime may occur with complex gadget
application, however it can be easily reproduced for testing purpose as
follows:
a. use isoc binterval as 1 in f_sourcesink.
b. use pattern=0
c. introduce a delay of 150us deliberately in source_sink_complete, so
that after few frames it lands into scenario 2.
d. now run testusb 16 (isoc in test). You will notice that if this
patch is not applied then isoc transfer is not able to recover after
first missed.
Current patch's approach is as under:
If missed isoc occurs and there is no request queued then issue END
TRANSFER, so that core generates next xfernotready and we will issue a
fresh START TRANSFER.
If there are still queued request then wait, do not issue either END or
UPDATE TRANSFER, just attach next request in request_list during giveback.
If any future queued request is successfully transferred then we will issue
UPDATE TRANSFER for all request in the request_list.
Cc: <[email protected]> # v3.6 v3.7 v3.8
Signed-off-by: Pratyush Anand <[email protected]>
Signed-off-by: Felipe Balbi <[email protected]>
---
drivers/usb/dwc3/core.h | 2 --
drivers/usb/dwc3/gadget.c | 36 ++++++++++++++++++++++++------------
2 files changed, 24 insertions(+), 14 deletions(-)
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index b7ca82c..7610cf5 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -407,7 +407,6 @@ struct dwc3_event_buffer {
* @number: endpoint number (1 - 15)
* @type: set to bmAttributes & USB_ENDPOINT_XFERTYPE_MASK
* @resource_index: Resource transfer index
- * @current_uf: Current uf received through last event parameter
* @interval: the intervall on which the ISOC transfer is started
* @name: a human readable name e.g. ep1out-bulk
* @direction: true for TX, false for RX
@@ -441,7 +440,6 @@ struct dwc3_ep {
u8 number;
u8 type;
u8 resource_index;
- u16 current_uf;
u32 interval;
char name[20];
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 113ec80..356a5a2 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1115,16 +1115,6 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep,
struct dwc3_request *req)
dep->name);
}
- /*
- * 3. Missed ISOC Handling. We need to start isoc transfer on the saved
- * uframe number.
- */
- if (usb_endpoint_xfer_isoc(dep->endpoint.desc) &&
- (dep->flags & DWC3_EP_MISSED_ISOC)) {
- __dwc3_gadget_start_isoc(dwc, dep, dep->current_uf);
- dep->flags &= ~DWC3_EP_MISSED_ISOC;
- }
-
return 0;
}
@@ -1686,14 +1676,29 @@ static int dwc3_cleanup_done_reqs(struct dwc3 *dwc,
struct dwc3_ep *dep,
if (trb_status == DWC3_TRBSTS_MISSED_ISOC) {
dev_dbg(dwc->dev, "incomplete IN
transfer %s\n",
dep->name);
- dep->current_uf = event->parameters &
- ~(dep->interval - 1);
+ /*
+ * If missed isoc occurred and there is
+ * no request queued then issue END
+ * TRANSFER, so that core generates
+ * next xfernotready and we will issue
+ * a fresh START TRANSFER.
+ * If there are still queued request
+ * then wait, do not issue either END
+ * or UPDATE TRANSFER, just attach next
+ * request in request_list during
+ * giveback.If any future queued request
+ * is successfully transferred then we
+ * will issue UPDATE TRANSFER for all
+ * request in the request_list.
+ */
dep->flags |= DWC3_EP_MISSED_ISOC;
} else {
dev_err(dwc->dev, "incomplete IN
transfer %s\n",
dep->name);
status = -ECONNRESET;
}
+ } else {
+ dep->flags &= ~DWC3_EP_MISSED_ISOC;
}
} else {
if (count && (event->status & DEPEVT_STATUS_SHORT))
@@ -1720,6 +1725,13 @@ static int dwc3_cleanup_done_reqs(struct dwc3 *dwc,
struct dwc3_ep *dep,
break;
} while (1);
+ if (list_empty(&dep->req_queued) &&
+ (dep->flags & DWC3_EP_MISSED_ISOC)) {
+ dwc3_stop_active_transfer(dwc, dep->number);
+ dep->flags &= ~DWC3_EP_MISSED_ISOC;
+ return 1;
+ }
+
if ((event->status & DEPEVT_STATUS_IOC) &&
(trb->ctrl & DWC3_TRB_CTRL_IOC))
return 0;
--
1.8.1.rc1.5.g7e0651a
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
