From da10bcdd6f70dc9977f2cf18f4783cf78520623a Mon Sep 17 00:00:00 2001
From: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Date: Wed, 18 Dec 2019 18:14:50 -0800
Subject: [PATCH] usb: dwc3: gadget: Delay starting transfer
Git-commit: da10bcdd6f70dc9977f2cf18f4783cf78520623a
Patch-mainline: v5.6-rc1
References: git-fixes
If the END_TRANSFER command hasn't completed yet, then don't send the
START_TRANSFER command. The controller may not be able to start if
that's the case. Some controller revisions depend on this. See
commit 76a638f8ac0d ("usb: dwc3: gadget: wait for End Transfer to
complete"). Let's only send START_TRANSFER command after the
END_TRANSFER command had completed.
Fixes: 3aec99154db3 ("usb: dwc3: gadget: remove DWC3_EP_END_TRANSFER_PENDING")
Signed-off-by: Thinh Nguyen <thinhn@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/usb/dwc3/core.h | 1 +
drivers/usb/dwc3/gadget.c | 11 +++++++++++
2 files changed, 12 insertions(+)
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index da0af11fbc1a..77c4a9abe365 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -690,6 +690,7 @@ struct dwc3_ep {
#define DWC3_EP_TRANSFER_STARTED BIT(3)
#define DWC3_EP_END_TRANSFER_PENDING BIT(4)
#define DWC3_EP_PENDING_REQUEST BIT(5)
+#define DWC3_EP_DELAY_START BIT(6)
/* This last one is specific to EP0 */
#define DWC3_EP0_DIR_IN BIT(31)
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index cf163dcc5524..696fbeb8d03a 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1450,6 +1450,12 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req)
list_add_tail(&req->list, &dep->pending_list);
req->status = DWC3_REQUEST_STATUS_QUEUED;
+ /* Start the transfer only after the END_TRANSFER is completed */
+ if (dep->flags & DWC3_EP_END_TRANSFER_PENDING) {
+ dep->flags |= DWC3_EP_DELAY_START;
+ return 0;
+ }
+
/*
* NOTICE: Isochronous endpoints should NEVER be prestarted. We must
* wait for a XferNotReady event so we will know what's the current
@@ -2631,6 +2637,11 @@ static void dwc3_endpoint_interrupt(struct dwc3 *dwc,
dep->flags &= ~DWC3_EP_END_TRANSFER_PENDING;
dep->flags &= ~DWC3_EP_TRANSFER_STARTED;
dwc3_gadget_ep_cleanup_cancelled_requests(dep);
+ if ((dep->flags & DWC3_EP_DELAY_START) &&
+ !usb_endpoint_xfer_isoc(dep->endpoint.desc))
+ __dwc3_gadget_kick_transfer(dep);
+
+ dep->flags &= ~DWC3_EP_DELAY_START;
}
break;
case DWC3_DEPEVT_STREAMEVT:
--
2.16.4