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 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.

Signed-off-by: Matthieu CASTET <matthieu.cas...@parrot.com>
---
 drivers/usb/chipidea/udc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c
index 69d20fb..9e2e39b 100644
--- a/drivers/usb/chipidea/udc.c
+++ b/drivers/usb/chipidea/udc.c
@@ -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();
-- 
1.8.5.2

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