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From: Freddy Xin <freddy@asix.com.tw>
To: David Miller <davem@davemloft.net>
Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
	netdev@vger.kernel.org, louis@asix.com.tw, allan@asix.com.tw
Subject: Re: [PATCH 1/1] AX88179_178A: Enable the hardware pseudo header in case of the NET_IP_ALIGN equals 0
Date: Wed, 11 Dec 2013 14:17:59 +0800	[thread overview]
Message-ID: <52A80397.2080508@asix.com.tw> (raw)
In-Reply-To: <20131209.200131.1376169274733452706.davem@davemloft.net>


On 2013年12月10日 09:01, David Miller wrote:
> From: freddy@asix.com.tw
> Date: Fri,  6 Dec 2013 17:58:18 +0800
>
>> From: Freddy Xin <freddy@asix.com.tw>
>>
>> The AX88179_178A has a hardware feature that it can insert a 2-bytes pseudo
>> header in front of each received frame by setting the AX_RX_CTL_IPE bit.
>> This feature is used to let the IP header be aligned on a doubleword-aligned address,
>> but the NET_IP_ALIGN may equals to 2 and the __netdev_alloc_skb_ip_align in USBNET will
>> reserve 2 bytes also, so in this case the driver shouldn't enable this bit.
>>
>> This patch modifies the driver to set AX_RX_CTL_IPE just in case of the NET_IP_ALIGN equals 0.
>>
>> Signed-off-by: Freddy Xin <freddy@asix.com.tw>
> Please avoid larger than 80 column lines in your commit messages,
> people use text-only tools to viee these.
>
> Next, it makes no sense to restrict your change to NET_IP_ALIGN==0
>
> Simply handle any case, by undoing the reservation if it's getting
> in the way.  If there isn't an appropriate helper for this, add one.
>
I think there is no way of undoing the reservation in the driver.
Can I add a flag of the driver_info, and use it to determine
whether undoing the reservation in rx_submit of usbnet?

  reply	other threads:[~2013-12-11  6:23 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-12-06  9:58 [PATCH 1/1] AX88179_178A: Enable the hardware pseudo header in case of the NET_IP_ALIGN equals 0 freddy
2013-12-10  1:01 ` David Miller
2013-12-11  6:17   ` Freddy Xin [this message]
2013-12-11 10:33     ` David Laight
2013-12-11 17:16     ` David Miller

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