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From: David Miller <davem@davemloft.net>
To: thomas.lendacky@amd.com
Cc: netdev@vger.kernel.org
Subject: Re: [PATCH net] amd-xgbe: Fix jumbo MTU processing on newer hardware
Date: Wed, 15 Mar 2017 16:43:42 -0700 (PDT)	[thread overview]
Message-ID: <20170315.164342.1399522126912671968.davem@davemloft.net> (raw)
In-Reply-To: <1b4a099a-66a8-3fdb-01ed-bc110756244a@amd.com>

From: Tom Lendacky <thomas.lendacky@amd.com>
Date: Wed, 15 Mar 2017 17:52:44 -0500

> On 3/15/2017 5:41 PM, David Miller wrote:
>> From: Tom Lendacky <thomas.lendacky@amd.com>
>> Date: Wed, 15 Mar 2017 17:40:51 -0500
>>
>>> On 3/15/2017 5:37 PM, David Miller wrote:
>>>> From: Tom Lendacky <thomas.lendacky@amd.com>
>>>> Date: Wed, 15 Mar 2017 15:11:23 -0500
>>>>
>>>>> Newer hardware does not provide a cumulative payload length when
>>>>> multiple
>>>>> descriptors are needed to handle the data. Once the MTU increases
>>>>> beyond
>>>>> the size that can be handled by a single descriptor, the SKB does not
>>>>> get
>>>>> built properly by the driver.
>>>>>
>>>>> The driver will now calculate the size of the data buffers used by the
>>>>> hardware.  The first buffer of the first descriptor is for packet
>>>>> headers
>>>>> or packet headers and data when the headers can't be split. Subsequent
>>>>> descriptors in a multi-descriptor chain will not use the first
>>>>> buffer. The
>>>>> second buffer is used by all the descriptors in the chain for payload
>>>>> data.
>>>>> Based on whether the driver is processing the first, intermediate, or
>>>>> last
>>>>> descriptor it can calculate the buffer usage and build the SKB
>>>>> properly.
>>>>>
>>>>> Tested and verified on both old and new hardware.
>>>>>
>>>>> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
>>>>
>>>> Applied, thanks Tom.
>>>
>>> Thanks David.  This is another patch for 4.10 stable. Can you please
>>> queue it up?
>>
>> Can you properly state this in your patch postings, instead of always
>> mentioning it later?
>>
> 
> Sorry, yes, I can do that.  I didn't realize you preferred it that
> way.
> Do you want the "Cc" tag to stable included in the patch or just
> mention the stable targets in the patch description?  I know you
> coordinate the stable submissions and I don't want to mess anything
> up.

Just put a note after a "---" delimiter, requesting that I queue it up
for -stable.

Thanks.

      parent reply	other threads:[~2017-03-15 23:49 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-15 20:11 [PATCH net] amd-xgbe: Fix jumbo MTU processing on newer hardware Tom Lendacky
2017-03-15 22:37 ` David Miller
2017-03-15 22:40   ` Tom Lendacky
2017-03-15 22:41     ` David Miller
2017-03-15 22:52       ` Tom Lendacky
2017-03-15 23:11         ` Tom Lendacky
2017-03-15 23:43         ` David Miller [this message]

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