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

[Jon Hunter]

On 23/07/2019 11:07, Jose Abreu wrote:
> From: Jon Hunter <jonathanh@xxxxxxxxxx>
> Date: Jul/23/2019, 11:01:24 (UTC+00:00)
> 
>> This appears to be a winner and by disabling the SMMU for the ethernet
>> controller and reverting commit 954a03be033c7cef80ddc232e7cbdb17df735663
>> this worked! So yes appears to be related to the SMMU being enabled. We
>> had to enable the SMMU for ethernet recently due to commit
>> 954a03be033c7cef80ddc232e7cbdb17df735663.
> 
> Finally :)
> 
> However, from "git show 954a03be033c7cef80ddc232e7cbdb17df735663":
> 
> +         There are few reasons to allow unmatched stream bypass, and
> +         even fewer good ones.  If saying YES here breaks your board
> +         you should work on fixing your board.
> 
> So, how can we fix this ? Is your ethernet DT node marked as 
> "dma-coherent;" ?

TBH I have no idea. I can't say I fully understand your change or how it
is breaking things for us.

Currently, the Tegra DT binding does not have 'dma-coherent' set. I see
this is optional, but I am not sure how you determine whether or not
this should be set.

Jon

-- 
nvpublic