From: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
To: Felipe Balbi <balbi@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Thinh Nguyen <Thinh.Nguyen@synopsys.com>,
linux-usb@vger.kernel.org
Cc: John Youn <John.Youn@synopsys.com>
Subject: [PATCH v2 3/4] usb: dwc3: gadget: Issue END_TRANSFER to retry isoc transfer
Date: Sun, 29 Mar 2020 16:13:10 -0700 [thread overview]
Message-ID: <dda524d74ae8b31a75fe8e6678e37e5bce3b3575.1585523081.git.thinhn@synopsys.com> (raw)
In-Reply-To: <cover.1585523081.git.thinhn@synopsys.com>
After a number of unsuccessful start isoc attempts due to bus-expiry
status, issue END_TRANSFER command and retry on the next XferNotReady
event.
Signed-off-by: Thinh Nguyen <thinhn@synopsys.com>
---
drivers/usb/dwc3/gadget.c | 36 +++++++++++++++++++++++++++++++++++-
1 file changed, 35 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 7989fe663300..ee87b7b383f6 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1413,7 +1413,8 @@ static int __dwc3_gadget_start_isoc(struct dwc3_ep *dep)
int ret;
int i;
- if (list_empty(&dep->pending_list)) {
+ if (list_empty(&dep->pending_list) &&
+ list_empty(&dep->started_list)) {
dep->flags |= DWC3_EP_PENDING_REQUEST;
return -EAGAIN;
}
@@ -1436,6 +1437,27 @@ static int __dwc3_gadget_start_isoc(struct dwc3_ep *dep)
break;
}
+ /*
+ * After a number of unsuccessful start attempts due to bus-expiry
+ * status, issue END_TRANSFER command and retry on the next XferNotReady
+ * event.
+ */
+ if (ret == -EAGAIN) {
+ struct dwc3_gadget_ep_cmd_params params;
+ u32 cmd;
+
+ cmd = DWC3_DEPCMD_ENDTRANSFER |
+ DWC3_DEPCMD_CMDIOC |
+ DWC3_DEPCMD_PARAM(dep->resource_index);
+
+ dep->resource_index = 0;
+ memset(¶ms, 0, sizeof(params));
+
+ ret = dwc3_send_gadget_ep_cmd(dep, cmd, ¶ms);
+ if (!ret)
+ dep->flags |= DWC3_EP_END_TRANSFER_PENDING;
+ }
+
return ret;
}
@@ -2645,6 +2667,18 @@ static void dwc3_gadget_endpoint_transfer_not_ready(struct dwc3_ep *dep,
const struct dwc3_event_depevt *event)
{
dwc3_gadget_endpoint_frame_from_event(dep, event);
+
+ /*
+ * The XferNotReady event is generated only once before the endpoint
+ * starts. It will be generated again when END_TRANSFER command is
+ * issued. For some controller versions, the XferNotReady event may be
+ * generated while the END_TRANSFER command is still in process. Ignore
+ * it and wait for the next XferNotReady event after the command is
+ * completed.
+ */
+ if (dep->flags & DWC3_EP_END_TRANSFER_PENDING)
+ return;
+
(void) __dwc3_gadget_start_isoc(dep);
}
--
2.11.0
next prev parent reply other threads:[~2020-03-29 23:13 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-29 23:12 [PATCH v2 0/4] usb: dwc3: gadget: Improve isoc starting mechanism Thinh Nguyen
2020-03-29 23:12 ` [PATCH v2 1/4] usb: dwc3: gadget: Properly handle failed kick_transfer Thinh Nguyen
2020-03-29 23:13 ` [PATCH v2 2/4] usb: dwc3: gadget: Store resource index of start cmd Thinh Nguyen
2020-03-29 23:13 ` Thinh Nguyen [this message]
2020-03-29 23:13 ` [PATCH v2 4/4] usb: dwc3: gadget: WARN on no-resource status Thinh Nguyen
2020-03-30 8:15 ` [PATCH v2 0/4] usb: dwc3: gadget: Improve isoc starting mechanism Felipe Balbi
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