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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Cristian Birsan <cristian.birsan@microchip.com>,
        Felipe Balbi <balbi@kernel.org>
Subject: [PATCH 5.4 08/83] usb: gadget: udc: atmel: Fix vbus disconnect handling
Date:   Fri,  1 May 2020 15:22:47 +0200
Message-Id: <20200501131525.999344083@linuxfoundation.org>
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From: Cristian Birsan <cristian.birsan@microchip.com>

commit 12b94da411f9c6d950beb067d913024fd5617a61 upstream.

A DMA transfer can be in progress while vbus is lost due to a cable
disconnect. For endpoints that use DMA, this condition can lead to
peripheral hang. The patch ensures that endpoints are disabled before
the clocks are stopped to prevent this issue.

Fixes: a64ef71ddc13 ("usb: gadget: atmel_usba_udc: condition clocks to vbus state")
Signed-off-by: Cristian Birsan <cristian.birsan@microchip.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/usb/gadget/udc/atmel_usba_udc.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/usb/gadget/udc/atmel_usba_udc.c
+++ b/drivers/usb/gadget/udc/atmel_usba_udc.c
@@ -1950,10 +1950,10 @@ static irqreturn_t usba_vbus_irq_thread(
 			usba_start(udc);
 		} else {
 			udc->suspended = false;
-			usba_stop(udc);
-
 			if (udc->driver->disconnect)
 				udc->driver->disconnect(&udc->gadget);
+
+			usba_stop(udc);
 		}
 		udc->vbus_prev = vbus;
 	}