Subject: Re: [PATCH 1/2] net: macb: Separate rx and tx ring init function

From: Varka Bhadram <[email-masked]>
Date: Fri, 18 Jul 2014 15:40:08 +0530

On 07/18/2014 03:22 PM, Neil Armstrong wrote:
> A single method is called to initialize the TX and RX
> rings. Separate the methods into distinct ones for
> MACB and GEM context.
>
> Signed-off-by: Neil Armstrong <[email-masked]>
> ---
>   drivers/net/ethernet/cadence/macb.c |   33 ++++++++++++++++++++++++---------
>   drivers/net/ethernet/cadence/macb.h |    3 ++-
>   2 files changed, 26 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/net/ethernet/cadence/macb.c b/drivers/net/ethernet/cadence/macb.c
> index e9daa07..20ad483 100644
> --- a/drivers/net/ethernet/cadence/macb.c
> +++ b/drivers/net/ethernet/cadence/macb.c
> @@ -1219,7 +1219,14 @@ out_err:
>   	return -ENOMEM;
>   }
>   
> -static void gem_init_rings(struct macb *bp)
> +static void gem_init_rx_rings(struct macb *bp)
> +{
> +	bp->rx_tail = bp->rx_prepared_head = 0;
> +
> +	gem_rx_refill(bp);
> +}
> +
> +static void gem_init_tx_rings(struct macb *bp)
>   {
>   	int i;
>   
> @@ -1229,12 +1236,10 @@ static void gem_init_rings(struct macb *bp)
>   	}
>   	bp->tx_ring[TX_RING_SIZE - 1].ctrl |= MACB_BIT(TX_WRAP);
>   
> -	bp->rx_tail = bp->rx_prepared_head = bp->tx_head = bp->tx_tail = 0;
> -
> -	gem_rx_refill(bp);
> +	bp->tx_head = bp->tx_tail = 0;

This is not the preferred way of doing it....

multiple assignments should be avoided

>   }
>   
> -static void macb_init_rings(struct macb *bp)
> +static void macb_init_rx_rings(struct macb *bp)
>   {
>   	int i;
>   	dma_addr_t addr;
> @@ -1247,13 +1252,20 @@ static void macb_init_rings(struct macb *bp)
>   	}
>   	bp->rx_ring[RX_RING_SIZE - 1].addr |= MACB_BIT(RX_WRAP);
>   
> +	bp->rx_tail = 0;
> +}
> +
> +static void macb_init_tx_rings(struct macb *bp)
> +{
> +	int i;
> +
>   	for (i = 0; i < TX_RING_SIZE; i++) {
>   		bp->tx_ring[i].addr = 0;
>   		bp->tx_ring[i].ctrl = MACB_BIT(TX_USED);
>   	}
>   	bp->tx_ring[TX_RING_SIZE - 1].ctrl |= MACB_BIT(TX_WRAP);
>   
> -	bp->rx_tail = bp->tx_head = bp->tx_tail = 0;
> +	bp->tx_head = bp->tx_tail = 0;

Dto...

>   }
>   
>   static void macb_reset_hw(struct macb *bp)
> @@ -1554,7 +1566,8 @@ static int macb_open(struct net_device *dev)
>   
>   	napi_enable(&bp->napi);
>   
> -	bp->macbgem_ops.mog_init_rings(bp);
> +	bp->macbgem_ops.mog_init_rx_rings(bp);
> +	bp->macbgem_ops.mog_init_tx_rings(bp);
>   	macb_init_hw(bp);
>   
>   	/* schedule a link state check */
> @@ -1901,12 +1914,14 @@ static int __init macb_probe(struct platform_device *pdev)
>   	if (macb_is_gem(bp)) {
>   		bp->macbgem_ops.mog_alloc_rx_buffers = gem_alloc_rx_buffers;
>   		bp->macbgem_ops.mog_free_rx_buffers = gem_free_rx_buffers;
> -		bp->macbgem_ops.mog_init_rings = gem_init_rings;
> +		bp->macbgem_ops.mog_init_rx_rings = gem_init_rx_rings;
> +		bp->macbgem_ops.mog_init_tx_rings = gem_init_tx_rings;
>   		bp->macbgem_ops.mog_rx = gem_rx;
>   	} else {
>   		bp->macbgem_ops.mog_alloc_rx_buffers = macb_alloc_rx_buffers;
>   		bp->macbgem_ops.mog_free_rx_buffers = macb_free_rx_buffers;
> -		bp->macbgem_ops.mog_init_rings = macb_init_rings;
> +		bp->macbgem_ops.mog_init_rx_rings = macb_init_rx_rings;
> +		bp->macbgem_ops.mog_init_tx_rings = macb_init_tx_rings;
>   		bp->macbgem_ops.mog_rx = macb_rx;
>   	}
>   
> diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
> index 51c0244..8016d08 100644
> --- a/drivers/net/ethernet/cadence/macb.h
> +++ b/drivers/net/ethernet/cadence/macb.h
> @@ -550,7 +550,8 @@ struct macb;
>   struct macb_or_gem_ops {
>   	int	(*mog_alloc_rx_buffers)(struct macb *bp);
>   	void	(*mog_free_rx_buffers)(struct macb *bp);
> -	void	(*mog_init_rings)(struct macb *bp);
> +	void	(*mog_init_rx_rings)(struct macb *bp);
> +	void	(*mog_init_tx_rings)(struct macb *bp);
>   	int	(*mog_rx)(struct macb *bp, int budget);
>   };
>   

-- 
Regards,
Varka Bhadram.