[Linux-stm32] [PATCH net-next 3/3] net: stmmac: Introducing support for Page Pool

[Jon Hunter]

On 29/07/2019 09:16, Jose Abreu wrote:
> From: Jose Abreu <joabreu at synopsys.com>
> Date: Jul/27/2019, 16:56:37 (UTC+00:00)
> 
>> From: Jon Hunter <jonathanh at nvidia.com>
>> Date: Jul/26/2019, 15:11:00 (UTC+00:00)
>>
>>>
>>> On 25/07/2019 16:12, Jose Abreu wrote:
>>>> From: Jon Hunter <jonathanh at nvidia.com>
>>>> Date: Jul/25/2019, 15:25:59 (UTC+00:00)
>>>>
>>>>>
>>>>> On 25/07/2019 14:26, Jose Abreu wrote:
>>>>>
>>>>> ...
>>>>>
>>>>>> Well, I wasn't expecting that :/
>>>>>>
>>>>>> Per documentation of barriers I think we should set descriptor fields 
>>>>>> and then barrier and finally ownership to HW so that remaining fields 
>>>>>> are coherent before owner is set.
>>>>>>
>>>>>> Anyway, can you also add a dma_rmb() after the call to 
>>>>>> stmmac_rx_status() ?
>>>>>
>>>>> Yes. I removed the debug print added the barrier, but that did not help.
>>>>
>>>> So, I was finally able to setup NFS using your replicated setup and I 
>>>> can't see the issue :(
>>>>
>>>> The only difference I have from yours is that I'm using TCP in NFS 
>>>> whilst you (I believe from the logs), use UDP.
>>>
>>> So I tried TCP by setting the kernel boot params to 'nfsvers=3' and
>>> 'proto=tcp' and this does appear to be more stable, but not 100% stable.
>>> It still appears to fail in the same place about 50% of the time.
>>>
>>>> You do have flow control active right ? And your HW FIFO size is >= 4k ?
>>>
>>> How can I verify if flow control is active?
>>
>> You can check it by dumping register MTL_RxQ_Operation_Mode (0xd30).

Where would be the appropriate place to dump this? After probe? Maybe
best if you can share a code snippet of where to dump this.

>> Can you also add IOMMU debug in file "drivers/iommu/iommu.c" ?

You can find a boot log here:

https://paste.ubuntu.com/p/qtRqtYKHGF/

> And, please try attached debug patch.

With this patch it appears to boot fine. So far no issues seen.

Jon

-- 
nvpublic