| From foo@baz Thu Dec 8 07:19:12 CET 2016 |
| From: Cyrille Pitchen <cyrille.pitchen@atmel.com> |
| Date: Mon, 28 Nov 2016 14:40:55 +0100 |
| Subject: net: macb: fix the RX queue reset in macb_rx() |
| |
| From: Cyrille Pitchen <cyrille.pitchen@atmel.com> |
| |
| |
| [ Upstream commit a0b44eea372b449ef9744fb1d90491cc063289b8 ] |
| |
| On macb only (not gem), when a RX queue corruption was detected from |
| macb_rx(), the RX queue was reset: during this process the RX ring |
| buffer descriptor was initialized by macb_init_rx_ring() but we forgot |
| to also set bp->rx_tail to 0. |
| |
| Indeed, when processing the received frames, bp->rx_tail provides the |
| macb driver with the index in the RX ring buffer of the next buffer to |
| process. So when the whole ring buffer is reset we must also reset |
| bp->rx_tail so the driver is synchronized again with the hardware. |
| |
| Since macb_init_rx_ring() is called from many locations, currently from |
| macb_rx() and macb_init_rings(), we'd rather add the "bp->rx_tail = 0;" |
| line inside macb_init_rx_ring() than add the very same line after each |
| call of this function. |
| |
| Without this fix, the rx queue is not reset properly to recover from |
| queue corruption and connection drop may occur. |
| |
| Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com> |
| Fixes: 9ba723b081a2 ("net: macb: remove BUG_ON() and reset the queue to handle RX errors") |
| Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/net/ethernet/cadence/macb.c | 3 +-- |
| 1 file changed, 1 insertion(+), 2 deletions(-) |
| |
| --- a/drivers/net/ethernet/cadence/macb.c |
| +++ b/drivers/net/ethernet/cadence/macb.c |
| @@ -959,6 +959,7 @@ static inline void macb_init_rx_ring(str |
| addr += bp->rx_buffer_size; |
| } |
| bp->rx_ring[RX_RING_SIZE - 1].addr |= MACB_BIT(RX_WRAP); |
| + bp->rx_tail = 0; |
| } |
| |
| static int macb_rx(struct macb *bp, int budget) |
| @@ -1597,8 +1598,6 @@ static void macb_init_rings(struct macb |
| bp->queues[0].tx_head = 0; |
| bp->queues[0].tx_tail = 0; |
| bp->queues[0].tx_ring[TX_RING_SIZE - 1].ctrl |= MACB_BIT(TX_WRAP); |
| - |
| - bp->rx_tail = 0; |
| } |
| |
| static void macb_reset_hw(struct macb *bp) |
