Re: [PATCH v2] arm64: dts: rockchip: add rk3399 UART DMAs

[Robin Murphy]

On 2019-03-27 12:00 pm, Heiko Stuebner wrote:
> Hi,
>
> Am Dienstag, 26. MÃrz 2019, 14:49:16 CET schrieb Katsuhiro Suzuki:
> > Hello Robin,
> >
> > Sorry for inconvenience. Since I don't adhere enabling DMA for UARTs,
> > please revert my patch if you need.
>
> I've dropped the patch from my queue now.
>
> > BTW, there are DMA properties in RK3328 device-tree like as this patch.
> > RK3328 UART DMA could not work correctly too...??
>
> I remember Rockcihip dma-controllers having issues with burst-sizes
> and flushing (there is a no-flushp option in pl330), so it's
> possible that all share the same error up to rk3399 and rk3328
>
> But so far no-one has shouted regarding the rk3328.

Let me be the first, then, I guess :)

I found an easy way to observe the problem on my 3399, and I've just 
fired up my 3328 box with a 5.0 distro kernel to find that it behaves 
the same. Basically just dump a large pile of text into 'less' on the 
serial console, and scroll through line-by-line - certain lines get 
dropped except for a few characters at the end.

I'll see if I can narrow it down a bit, starting with trying 
broken-flushp...

Robin.