On 07/05/2019 at 16:29, Harini Katakam wrote:
> External E-Mail
>
>
> Current order in open:
> -> Enable interrupts (macb_init_hw)
> -> Enable NAPI
> -> Start PHY
>
> Sequence of RX handling:
> -> RX interrupt occurs
> -> Interrupt is cleared and interrupt bits disabled in handler
> -> NAPI is scheduled
> -> In NAPI, RX budget is processed and RX interrupts are re-enabled
>
> With the above, on QEMU or fixed link setups (where PHY state doesn't
> matter), there's a chance macb RX interrupt occurs before NAPI is
> enabled. This will result in NAPI being scheduled before it is enabled.
> Fix this macb open by changing the order.
>
> Fixes: ae1f2a56d273 ("net: macb: Added support for many RX queues")
> Signed-off-by: Harini Katakam <harini.kata...@xilinx.com>
it looks okay to me:
Acked-by: Nicolas Ferre <nicolas.fe...@microchip.com>
> ---
> drivers/net/ethernet/cadence/macb_main.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/ethernet/cadence/macb_main.c
> b/drivers/net/ethernet/cadence/macb_main.c
> index 5d5c9d7..c049410 100644
> --- a/drivers/net/ethernet/cadence/macb_main.c
> +++ b/drivers/net/ethernet/cadence/macb_main.c
> @@ -2427,12 +2427,12 @@ static int macb_open(struct net_device *dev)
> goto pm_exit;
> }
>
> - bp->macbgem_ops.mog_init_rings(bp);
> - macb_init_hw(bp);
> -
> for (q = 0, queue = bp->queues; q < bp->num_queues; ++q, ++queue)
> napi_enable(&queue->napi);
>
> + bp->macbgem_ops.mog_init_rings(bp);
> + macb_init_hw(bp);
> +
> /* schedule a link state check */
> phy_start(dev->phydev);
>
>
--
Nicolas Ferre
