[Intel-wired-lan] [PATCH] intel: ice: Do not enable NAPI on q_vectors that have no rings

[Jeff Kirsher <jeffrey.t.kirsher@intel.com>]

On Wed, 2018-11-28 at 12:24 +0000, Yang Xiao wrote:
> From: Young Xiao <YangX92@hotmail.com>
> 
> If ice driver has q_vectors w/ active NAPI that has no rings,
> then this will result in a divide by zero error. To correct it
> I am updating the driver code so that we only support NAPI on
> q_vectors that have 1 or more rings allocated to them.
> 
> See commit 13a8cd191a2b ("i40e: Do not enable NAPI on q_vectors
> that have no rings") for detail.
> 
> Signed-off-by: Young Xiao <YangX92@hotmail.com>
> ---
>  drivers/net/ethernet/intel/ice/ice_main.c | 16 ++++++++++++----
>  1 file changed, 12 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/ice/ice_main.c
> b/drivers/net/ethernet/intel/ice/ice_main.c
> index 333312a..9cc988a 100644
> --- a/drivers/net/ethernet/intel/ice/ice_main.c
> +++ b/drivers/net/ethernet/intel/ice/ice_main.c
> @@ -2563,8 +2563,12 @@ static void ice_napi_enable_all(struct ice_vsi
> *vsi)
>  	if (!vsi->netdev)
>  		return;
>  
> -	for (q_idx = 0; q_idx < vsi->num_q_vectors; q_idx++)
> -		napi_enable(&vsi->q_vectors[q_idx]->napi);
> +	for (q_idx = 0; q_idx < vsi->num_q_vectors; q_idx++) {
> +		struct ice_q_vector *q_vector = vsi->q_vectors[q_idx];
> +
> +		if (q_vector->rx.ring || q_vector->tx.ring)
> +			napi_enable(&q_vector->napi);
> +	}
>  }
>  
>  /**
> @@ -2931,8 +2935,12 @@ static void ice_napi_disable_all(struct
> ice_vsi *vsi)
>  	if (!vsi->netdev)
>  		return;
>  
> -	for (q_idx = 0; q_idx < vsi->num_q_vectors; q_idx++)
> -		napi_disable(&vsi->q_vectors[q_idx]->napi);
> +	for (q_idx = 0; q_idx < vsi->num_q_vectors; q_idx++) {
> +		struct ice_q_vector *q_vector = vsi->q_vectors[q_idx];
> +
> +		if (q_vector->rx.ring || q_vector->tx.ring)
> +			napi_enable(&q_vector->napi);

Looks like a cut and paste error, you should be 'disabling' NAPI, not
enabling it here.

> +	}
>  }
>  
>  /**

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