[PATCH 3.2 100/152] usb: gadget: udc: atmel: fix possible IN hang issue

From: Ben Hutchings
Date: Mon Feb 16 2015 - 21:08:57 EST

3.2.67-rc1 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>
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
drivers/usb/gadget/atmel_usba_udc.c | 1 -
1 file changed, 1 deletion(-)

--- a/drivers/usb/gadget/atmel_usba_udc.c
+++ b/drivers/usb/gadget/atmel_usba_udc.c
@@ -1597,7 +1597,6 @@ static void usba_ep_irq(struct usba_udc
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);

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