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Date: Mon, 1 Feb 2010 21:13:24 +0100
From: Jarek Poplawski <jarkao2@gmail.com>
To: Stephen Hemminger <shemminger@linux-foundation.org>
Cc: Michael Breuer <mbreuer@majjas.com>, David Miller <davem@davemloft.net>,
       akpm@linux-foundation.org, flyboy@gmail.com,
       linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
       Michael Chan <mchan@broadcom.com>, Don Fry <pcnet32@verizon.net>,
       Francois Romieu <romieu@fr.zoreil.com>,
       Matt Carlson <mcarlson@broadcom.com>
Subject: Re: [PATCH] sky2:  receive dma mapping error handling
Message-ID: <20100201201323.GA3096@del.dom.local>
References: <20100128225621.GD3109@del.dom.local>
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 <20100131003449.GA11935@del.dom.local>
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On Mon, Feb 01, 2010 at 10:20:18AM -0800, Stephen Hemminger wrote:
> This fixes the fact that re->flags is always zero without causing
> other confusion.

Actually, there is a slight confusion: after tx_init() slots #0 are
skipped and waiting for tx_complete. Of course, no big deal, but no
problem with fixing it too, so there is the main difference between
these two patches. (Moving re->flags and re->skb initializations is
an optimization, but I tried to change only the buggy parts.)

Jarek P.

> 
> --- a/drivers/net/sky2.c	2010-02-01 10:07:42.676296236 -0800
> +++ b/drivers/net/sky2.c	2010-02-01 10:18:12.575044064 -0800
> @@ -1025,11 +1025,8 @@ static void sky2_prefetch_init(struct sk
>  static inline struct sky2_tx_le *get_tx_le(struct sky2_port *sky2, u16 *slot)
>  {
>  	struct sky2_tx_le *le = sky2->tx_le + *slot;
> -	struct tx_ring_info *re = sky2->tx_ring + *slot;
>  
>  	*slot = RING_NEXT(*slot, sky2->tx_ring_size);
> -	re->flags = 0;
> -	re->skb = NULL;
>  	le->ctrl = 0;
>  	return le;
>  }
> @@ -1622,8 +1619,7 @@ static unsigned tx_le_req(const struct s
>  	return count;
>  }
>  
> -static void sky2_tx_unmap(struct pci_dev *pdev,
> -			  const struct tx_ring_info *re)
> +static void sky2_tx_unmap(struct pci_dev *pdev, struct tx_ring_info *re)
>  {
>  	if (re->flags & TX_MAP_SINGLE)
>  		pci_unmap_single(pdev, pci_unmap_addr(re, mapaddr),
> @@ -1633,6 +1629,7 @@ static void sky2_tx_unmap(struct pci_dev
>  		pci_unmap_page(pdev, pci_unmap_addr(re, mapaddr),
>  			       pci_unmap_len(re, maplen),
>  			       PCI_DMA_TODEVICE);
> +	re->flags = 0;
>  }
>  
>  /*
> @@ -1839,6 +1836,7 @@ static void sky2_tx_complete(struct sky2
>  			dev->stats.tx_packets++;
>  			dev->stats.tx_bytes += skb->len;
>  
> +			re->skb = NULL;
>  			dev_kfree_skb_any(skb);
>  
>  			sky2->tx_next = RING_NEXT(idx, sky2->tx_ring_size);