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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 <felipe.balbi@linux.intel.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.9 45/65] usb: gadget: udc: atmel: Fix interrupt storm in FIFO mode.
Date:   Mon, 11 Nov 2019 19:28:45 +0100
Message-Id: <20191111181349.079145966@linuxfoundation.org>
In-Reply-To: <20191111181331.917659011@linuxfoundation.org>
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From: Cristian Birsan <cristian.birsan@microchip.com>

[ Upstream commit ba3a1a915c49cc3023e4ddfc88f21e7514e82aa4 ]

Fix interrupt storm generated by endpoints when working in FIFO mode.
The TX_COMPLETE interrupt is used only by control endpoints processing.
Do not enable it for other types of endpoints.

Fixes: 914a3f3b3754 ("USB: add atmel_usba_udc driver")
Signed-off-by: Cristian Birsan <cristian.birsan@microchip.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/usb/gadget/udc/atmel_usba_udc.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/gadget/udc/atmel_usba_udc.c b/drivers/usb/gadget/udc/atmel_usba_udc.c
index 9705bcdbc577f..57dd3bad95397 100644
--- a/drivers/usb/gadget/udc/atmel_usba_udc.c
+++ b/drivers/usb/gadget/udc/atmel_usba_udc.c
@@ -403,9 +403,11 @@ static void submit_request(struct usba_ep *ep, struct usba_request *req)
 		next_fifo_transaction(ep, req);
 		if (req->last_transaction) {
 			usba_ep_writel(ep, CTL_DIS, USBA_TX_PK_RDY);
-			usba_ep_writel(ep, CTL_ENB, USBA_TX_COMPLETE);
+			if (ep_is_control(ep))
+				usba_ep_writel(ep, CTL_ENB, USBA_TX_COMPLETE);
 		} else {
-			usba_ep_writel(ep, CTL_DIS, USBA_TX_COMPLETE);
+			if (ep_is_control(ep))
+				usba_ep_writel(ep, CTL_DIS, USBA_TX_COMPLETE);
 			usba_ep_writel(ep, CTL_ENB, USBA_TX_PK_RDY);
 		}
 	}
-- 
2.20.1