[3.13.y-ckt stable] Patch "usb: gadget: udc: atmel: fix possible IN hang issue" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    usb: gadget: udc: atmel: fix possible IN hang issue

to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11-ckt16.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From b73cd260d086e5db9c71ddfea539fd9a07f2949c Mon Sep 17 00:00:00 2001
From: Bo Shen <voice.shen at atmel.com>
Date: Wed, 17 Dec 2014 17:18:49 +0800
Subject: usb: gadget: udc: atmel: fix possible IN hang issue

commit 6785a1034461c2d2c205215f63a50a740896e55b upstream.

When receive data, the RXRDY in status register set by hardware
after a new packet has been stored in the endpoint FIFO. When it
is copied from FIFO, this bit is cleared which make the FIFO can
be accessed again.

In the receive_data() function, this bit RXRDY has been cleared.
So, after the receive_data() function return, this bit should
not be cleared again, or else it may cause the accessing FIFO
corrupt, which will make the data loss.

Fixes: 914a3f3b3754 (USB: add atmel_usba_udc driver)
Acked-by: Nicolas Ferre <nicolas.ferre at atmel.com>
Signed-off-by: Bo Shen <voice.shen at atmel.com>
Signed-off-by: Felipe Balbi <balbi at ti.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/usb/gadget/atmel_usba_udc.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/usb/gadget/atmel_usba_udc.c b/drivers/usb/gadget/atmel_usba_udc.c
index c22e718..cfb54b3 100644
--- a/drivers/usb/gadget/atmel_usba_udc.c
+++ b/drivers/usb/gadget/atmel_usba_udc.c
@@ -1572,7 +1572,6 @@ static void usba_ep_irq(struct usba_udc *udc, struct usba_ep *ep)
 	if ((epstatus & epctrl) & USBA_RX_BK_RDY) {
 		DBG(DBG_BUS, "%s: RX data ready\n", ep->ep.name);
 		receive_data(ep);
-		usba_ep_writel(ep, CLR_STA, USBA_RX_BK_RDY);
 	}
 }

--
1.9.1