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usb: chipidea: need to mask when writting endptflush and endptprime 

ENDPTFLUSH and ENDPTPRIME registers are set by software and clear
by hardware. There is a bit for each endpoint. When we are setting
a bit for an endpoint we should make sure we do not touch other
endpoint bit. There is a race condition if the hardware clear the
bit between the read and the write in hw_write.

Cc: stable <stable@vger.kernel.org> # 3.11+
Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Matthieu CASTET <matthieu.castet@parrot.com>
Tested-by: Michael Grzeschik <mgrzeschik@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Matthieu CASTET 2014-02-19 13:46:31 +08:00 committed by Greg Kroah-Hartman
parent 0fd7a82067
commit 5bf5dbeda2
1 changed files with 2 additions and 2 deletions
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4
drivers/usb/chipidea/udc.c
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@ -105,7 +105,7 @@ static int hw_ep_flush(struct ci_hdrc *ci, int num, int dir)
do {
/* flush any pending transfer */
hw_write(ci, OP_ENDPTFLUSH, BIT(n), BIT(n));
hw_write(ci, OP_ENDPTFLUSH, ~0, BIT(n));
while (hw_read(ci, OP_ENDPTFLUSH, BIT(n)))
cpu_relax();
} while (hw_read(ci, OP_ENDPTSTAT, BIT(n)));
@ -205,7 +205,7 @@ static int hw_ep_prime(struct ci_hdrc *ci, int num, int dir, int is_ctrl)
if (is_ctrl && dir == RX && hw_read(ci, OP_ENDPTSETUPSTAT, BIT(num)))
return -EAGAIN;
hw_write(ci, OP_ENDPTPRIME, BIT(n), BIT(n));
hw_write(ci, OP_ENDPTPRIME, ~0, BIT(n));
while (hw_read(ci, OP_ENDPTPRIME, BIT(n)))
cpu_relax();