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Date:   Tue, 24 May 2022 11:51:35 +0800
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Subject: Re: [PATCH V2] octeon_ep: Remove unnecessary cast
To:     Joe Perches <joe@perches.com>
CC:     <aayarekar@marvell.com>, <davem@davemloft.net>, <kuba@kernel.org>,
        <linux-kernel@vger.kernel.org>, <netdev@vger.kernel.org>,
        <pabeni@redhat.com>, <vburru@marvell.com>
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From:   baihaowen <baihaowen@meizu.com>
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在 2022/5/24 上午11:48, Joe Perches 写道:
> On Tue, 2022-05-24 at 11:28 +0800, Haowen Bai wrote:
>> ./drivers/net/ethernet/marvell/octeon_ep/octep_rx.c:161:18-40: WARNING:
>> casting value returned by memory allocation function to (struct
>> octep_rx_buffer *) is useless.
> []
>> diff --git a/drivers/net/ethernet/marvell/octeon_ep/octep_rx.c b/drivers/net/ethernet/marvell/octeon_ep/octep_rx.c
> []
>> @@ -158,8 +158,7 @@ static int octep_setup_oq(struct octep_device *oct, int q_no)
>>  		goto desc_dma_alloc_err;
>>  	}
>>  
>> -	oq->buff_info = (struct octep_rx_buffer *)
>> -			vzalloc(oq->max_count * OCTEP_OQ_RECVBUF_SIZE);
>> +	oq->buff_info = vcalloc(oq->max_count, OCTEP_OQ_RECVBUF_SIZE);
> trivia:
>
> Perhaps better to remove the used once #define OCTEP_OQ_RECVBUF_SIZE
> and use the more obvious
>
> 	oq->buff_info = vcalloc(oq->max_count, sizeof(struct octep_rx_buffer));
>
> though I believe the vcalloc may be better as kvcalloc as max_count isn't
> particularly high and struct octep_rx_buffer is small.
>
> Maybe:
> ---
>  drivers/net/ethernet/marvell/octeon_ep/octep_rx.c | 8 ++++----
>  drivers/net/ethernet/marvell/octeon_ep/octep_rx.h | 2 --
>  2 files changed, 4 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/net/ethernet/marvell/octeon_ep/octep_rx.c b/drivers/net/ethernet/marvell/octeon_ep/octep_rx.c
> index d9ae0937d17a8..d6a0da61db449 100644
> --- a/drivers/net/ethernet/marvell/octeon_ep/octep_rx.c
> +++ b/drivers/net/ethernet/marvell/octeon_ep/octep_rx.c
> @@ -158,8 +158,8 @@ static int octep_setup_oq(struct octep_device *oct, int q_no)
>  		goto desc_dma_alloc_err;
>  	}
>  
> -	oq->buff_info = (struct octep_rx_buffer *)
> -			vzalloc(oq->max_count * OCTEP_OQ_RECVBUF_SIZE);
> +	oq->buff_info = kvcalloc(oq->max_count, sizeof(struct octep_rx_buffer),
> +				 GFP_KERNEL);
>  	if (unlikely(!oq->buff_info)) {
>  		dev_err(&oct->pdev->dev,
>  			"Failed to allocate buffer info for OQ-%d\n", q_no);
> @@ -176,7 +176,7 @@ static int octep_setup_oq(struct octep_device *oct, int q_no)
>  	return 0;
>  
>  oq_fill_buff_err:
> -	vfree(oq->buff_info);
> +	kvfree(oq->buff_info);
>  	oq->buff_info = NULL;
>  buf_list_err:
>  	dma_free_coherent(oq->dev, desc_ring_size,
> @@ -230,7 +230,7 @@ static int octep_free_oq(struct octep_oq *oq)
>  
>  	octep_oq_free_ring_buffers(oq);
>  
> -	vfree(oq->buff_info);
> +	kvfree(oq->buff_info);
>  
>  	if (oq->desc_ring)
>  		dma_free_coherent(oq->dev,
> diff --git a/drivers/net/ethernet/marvell/octeon_ep/octep_rx.h b/drivers/net/ethernet/marvell/octeon_ep/octep_rx.h
> index 782a24f27f3e0..34a32d95cd4b3 100644
> --- a/drivers/net/ethernet/marvell/octeon_ep/octep_rx.h
> +++ b/drivers/net/ethernet/marvell/octeon_ep/octep_rx.h
> @@ -67,8 +67,6 @@ struct octep_rx_buffer {
>  	u64 len;
>  };
>  
> -#define OCTEP_OQ_RECVBUF_SIZE    (sizeof(struct octep_rx_buffer))
> -
>  /* Output Queue statistics. Each output queue has four stats fields. */
>  struct octep_oq_stats {
>  	/* Number of packets received from the Device. */
>
>
Good work, thanks for suggestion.

-- 
Haowen Bai

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