can: cc770: Fix stalls on rt-linux, remove redundant IRQ ack

commit f4353daf4905c0099fd25fa742e2ffd4a4bab26a upstream.

This has been reported to cause stalls on rt-linux.

Suggested-by: Richard Weinberger <richard@nod.at>
Tested-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andri Yngvason <andri.yngvason@marel.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/can/cc770/cc770.c b/drivers/net/can/cc770/cc770.c
index 1e37313054f3950ee30e6c6fccad874d9262013a..9fed163262e0be4a066bbeaba735df4045e65293 100644 (file)
--- a/drivers/net/can/cc770/cc770.c
+++ b/drivers/net/can/cc770/cc770.c
@@ -447,15 +447,6 @@ static netdev_tx_t cc770_start_xmit(struct sk_buff *skb, struct net_device *dev)
 
        stats->tx_bytes += dlc;
 
-
-       /*
-        * HM: We had some cases of repeated IRQs so make sure the
-        * INT is acknowledged I know it's already further up, but
-        * doing again fixed the issue
-        */
-       cc770_write_reg(priv, msgobj[mo].ctrl0,
-                       MSGVAL_UNC | TXIE_UNC | RXIE_UNC | INTPND_RES);
-
        return NETDEV_TX_OK;
 }
 
@@ -684,12 +675,6 @@ static void cc770_tx_interrupt(struct net_device *dev, unsigned int o)
        /* Nothing more to send, switch off interrupts */
        cc770_write_reg(priv, msgobj[mo].ctrl0,
                        MSGVAL_RES | TXIE_RES | RXIE_RES | INTPND_RES);
-       /*
-        * We had some cases of repeated IRQ so make sure the
-        * INT is acknowledged
-        */
-       cc770_write_reg(priv, msgobj[mo].ctrl0,
-                       MSGVAL_UNC | TXIE_UNC | RXIE_UNC | INTPND_RES);
 
        stats->tx_packets++;
        can_get_echo_skb(dev, 0);