[Intel-wired-lan] [PATCH net-queue v1] igc: Fix trying to register an already registered xdp_rxq

[Lennert Buytenhek <buytenh@wantstofly.org>]

On Wed, Jan 12, 2022 at 04:40:15PM -0800, Vinicius Costa Gomes wrote:

> When changing the number of RX descriptors, for example, by doing
> 
>  $ ethtool -G enp3s0 rx 1024
> 
> the XDP RX queue information (xdp_rxq) may be already registered, if
> it's registered there's no need to do any thing in relation to
> xdp_rxq, none of it's parameters will change if we change the number
> of descriptors, for example.
> 
> Fixes: 4609ffb9f615 ("igc: Refactor XDP rxq info registration")
> Reported-by: Lennert Buytenhek <buytenh@wantstofly.org>
> Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
> ---
> Lennert, I added your name and email to the Reported-by tag, please
> see if you are ok with it.

This patch seems to work -- thank you!

Tested-by: Lennert Buytenhek <buytenh@arista.com>

Could you use the same email address for Reported-by: ?


> diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
> index e29aadbc6744..d163139161fc 100644
> --- a/drivers/net/ethernet/intel/igc/igc_main.c
> +++ b/drivers/net/ethernet/intel/igc/igc_main.c
> @@ -1,6 +1,7 @@
>  // SPDX-License-Identifier: GPL-2.0
>  /* Copyright (c)  2018 Intel Corporation */
>  
> +#include "net/xdp.h"
>  #include <linux/module.h>
>  #include <linux/types.h>
>  #include <linux/if_vlan.h>
> @@ -499,12 +500,14 @@ int igc_setup_rx_resources(struct igc_ring *rx_ring)
>  	u8 index = rx_ring->queue_index;
>  	int size, desc_len, res;
>  
> -	res = xdp_rxq_info_reg(&rx_ring->xdp_rxq, ndev, index,
> -			       rx_ring->q_vector->napi.napi_id);
> -	if (res < 0) {
> -		netdev_err(ndev, "Failed to register xdp_rxq index %u\n",
> -			   index);
> -		return res;
> +	if (!xdp_rxq_info_is_reg(&rx_ring->xdp_rxq)) {
> +		res = xdp_rxq_info_reg(&rx_ring->xdp_rxq, ndev, index,
> +				       rx_ring->q_vector->napi.napi_id);
> +		if (res < 0) {
> +			netdev_err(ndev, "Failed to register xdp_rxq index %u\n",
> +				   index);
> +			return res;
> +		}
>  	}
>  
>  	size = sizeof(struct igc_rx_buffer) * rx_ring->count;
> -- 
> 2.34.1