From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jose Abreu <Jose.Abreu@synopsys.com>
Subject: Re: STMMAC driver with TSO enabled issue
Date: Fri, 25 May 2018 15:32:28 +0100
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To: Bhadram Varka <vbhadram@nvidia.com>,
        Jose Abreu <Jose.Abreu@synopsys.com>,
        "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
        Joao Pinto <Joao.Pinto@synopsys.com>
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On 25-05-2018 15:25, Bhadram Varka wrote:
> Hi Jose,
>
> On 5/25/2018 7:35 PM, Jose Abreu wrote:
>> Hi Bhadram,
>>
>> On 25-05-2018 05:41, Bhadram Varka wrote:
>>> Hi Jose,
>>>
>>> On 5/24/2018 3:01 PM, Jose Abreu wrote:
>>>> Hi Bhadram,
>>>>
>>>> On 24-05-2018 06:58, Bhadram Varka wrote:
>>>>>
>>>>> After some time if check Tx descriptor status - then I see
>>>>> only
>>>>> below
>>>>>
>>>>> [..]
>>>>> [85788.286730] 027 [0x827951b0]: 0xf854f000 0x0 0x16d8
>>>>> 0x90000000
>>>>>
>>>>> index 025 and 026 descriptors processed but not index 027.
>>>>>
>>>>> At this stage Tx DMA is always in below state -
>>>>>
>>>>> ■ 3'b011: Running (Reading Data from system memory
>>>>> buffer and queuing it to the Tx buffer (Tx FIFO))
>>>>
>>>> Thats strange, I think the descriptors look okay though. I will
>>>> need the registers values (before the lock) and, if
>>>> possible, the
>>>> git bisect output.
>>>
>>> Attaching the register dump file after the issue observed.
>>> Please check once.
>>>
>>
>> ----->8-----
>> 0x112c = 0x0000003F
>> 0x11ac = 0x0000003F
>> 0x122c = 0x0000003F
>> 0x12ac = 0x0000003F
>>
>> 0x1130 = 0x0000003F
>> 0x11b0 = 0x0000003F
>> 0x1230 = 0x0000003F
>> 0x12b0 = 0x0000003F
>> ----->8-----
>>
>> This can't be right, it should be DMA_{RX/TX}_SIZE - 1 = 511. Did
>> you change these values in the code?
>>
>
> Yes. I have changed the descriptor length to 64 - so that
> searching for the current descriptor status would be easy.

Ok, it shouldn't impact anything. The only thing I'm remembering
now is that you can have TSO not enabled in all DMA channels (HW
configuration allows this). Please check if TSO in single-queue
works.

Thanks and Best Regards,
Jose Miguel Abreu