[PATCH 3.13.y-ckt 042/103] usb: gadget: udc: atmel: fix possible IN hang issue

From: Kamal Mostafa
Date: Wed Feb 18 2015 - 19:54:35 EST

3.13.11-ckt16 -stable review patch. If anyone has any objections, please let me know.


From: Bo Shen <voice.shen@xxxxxxxxx>

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@xxxxxxxxx>
Signed-off-by: Bo Shen <voice.shen@xxxxxxxxx>
Signed-off-by: Felipe Balbi <balbi@xxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
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);
- usba_ep_writel(ep, CLR_STA, USBA_RX_BK_RDY);


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/