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Date:   Thu, 20 Feb 2020 10:11:01 -0800 (PST)
Message-Id: <20200220.101101.1993510182065744262.davem@davemloft.net>
To:     esben@geanix.com
Cc:     netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org, andrew@lunn.ch,
        michal.simek@xilinx.com, ynezz@true.cz
Subject: Re: [PATCH net 2/4] net: ll_temac: Add more error handling of
 dma_map_single() calls
From:   David Miller <davem@davemloft.net>
In-Reply-To: <87v9o18xqd.fsf@geanix.com>
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        <20200219.105954.1568022053134111448.davem@davemloft.net>
        <87v9o18xqd.fsf@geanix.com>
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From: Esben Haabendal <esben@geanix.com>
Date: Thu, 20 Feb 2020 09:32:58 +0100

> David Miller <davem@davemloft.net> writes:
> 
>> From: Esben Haabendal <esben@geanix.com>
>> Date: Wed, 19 Feb 2020 11:54:00 +0100
>>
>>> @@ -863,12 +865,13 @@ temac_start_xmit(struct sk_buff *skb, struct net_device *ndev)
>>>  	skb_dma_addr = dma_map_single(ndev->dev.parent, skb->data,
>>>  				      skb_headlen(skb), DMA_TO_DEVICE);
>>>  	cur_p->len = cpu_to_be32(skb_headlen(skb));
>>> +	if (WARN_ON_ONCE(dma_mapping_error(ndev->dev.parent, skb_dma_addr)))
>>> +		return NETDEV_TX_BUSY;
>>
>> The appropriate behavior in this situation is to drop the packet and return
>> NETDEV_TX_OK.
> 
> Ok, and I guess the same goes for the error handling of dma_map_single()
> of one of the fragments later in same function.

Yes.