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From:   Wesley Cheng <wcheng@codeaurora.org>
To:     balbi@kernel.org, gregkh@linuxfoundation.org
Cc:     linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org,
        Wesley Cheng <wcheng@codeaurora.org>
Subject: [PATCH] usb: dwc3: gadget: Restart DWC3 gadget when enabling pullup
Date:   Tue, 29 Dec 2020 15:00:37 -0800
Message-Id: <1609282837-21666-1-git-send-email-wcheng@codeaurora.org>
Precedence: bulk

usb_gadget_deactivate/usb_gadget_activate does not execute the UDC start
operation, which may leave EP0 disabled and event IRQs disabled when
re-activating the function. Move the enabling/disabling of USB EP0 and
device event IRQs to be performed in the pullup routine.

Fixes: ae7e86108b12 ("usb: dwc3: Stop active transfers before halting the
controller")

Tested-by: Michael Tretter <m.tretter@pengutronix.de>
Reported-by: Michael Tretter <m.tretter@pengutronix.de>
Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>
---
 drivers/usb/dwc3/gadget.c | 14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 5d879b7606d5..922c8b76e534 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1988,6 +1988,7 @@ static int dwc3_gadget_run_stop(struct dwc3 *dwc, int is_on, int suspend)
 
 static void dwc3_gadget_disable_irq(struct dwc3 *dwc);
 static void __dwc3_gadget_stop(struct dwc3 *dwc);
+static int __dwc3_gadget_start(struct dwc3 *dwc);
 
 static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)
 {
@@ -2050,6 +2051,8 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)
 			dwc->ev_buf->lpos = (dwc->ev_buf->lpos + count) %
 						dwc->ev_buf->length;
 		}
+	} else {
+		__dwc3_gadget_start(dwc);
 	}
 
 	ret = dwc3_gadget_run_stop(dwc, is_on, false);
@@ -2224,10 +2227,6 @@ static int dwc3_gadget_start(struct usb_gadget *g,
 	}
 
 	dwc->gadget_driver	= driver;
-
-	if (pm_runtime_active(dwc->dev))
-		__dwc3_gadget_start(dwc);
-
 	spin_unlock_irqrestore(&dwc->lock, flags);
 
 	return 0;
@@ -2253,13 +2252,6 @@ static int dwc3_gadget_stop(struct usb_gadget *g)
 	unsigned long		flags;
 
 	spin_lock_irqsave(&dwc->lock, flags);
-
-	if (pm_runtime_suspended(dwc->dev))
-		goto out;
-
-	__dwc3_gadget_stop(dwc);
-
-out:
 	dwc->gadget_driver	= NULL;
 	spin_unlock_irqrestore(&dwc->lock, flags);
 
-- 
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