Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Esben Haabendal <esben@geanix.com>
To:     David Miller <davem@davemloft.net>
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
References: <cover.1582108989.git.esben@geanix.com>
        <65907810dd82de3fcaad9869f328ab32800c67ea.1582108989.git.esben@geanix.com>
        <20200219.105954.1568022053134111448.davem@davemloft.net>
Date:   Thu, 20 Feb 2020 09:32:58 +0100
In-Reply-To: <20200219.105954.1568022053134111448.davem@davemloft.net> (David
        Miller's message of "Wed, 19 Feb 2020 10:59:54 -0800 (PST)")
Message-ID: <87v9o18xqd.fsf@geanix.com>
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.3 (gnu/linux)
MIME-Version: 1.0
Content-Type: text/plain
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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.

/Esben