[Letux-kernel] DMA driver (was Re: [PATCH 00/20] A bunch of JZ4730 fixups for letux-kernel)

[Paul Boddie]

On Friday, 15 January 2021 09:49:34 CET H. Nikolaus Schaller wrote:
> 
> Am 15.01.2021 um 00:49 schrieb Paul Boddie <paul at boddie.org.uk>:
> > 
> > Paul<0001-JZ4730-Fixed-DMA-interrupt-pending-tests.patch>
> 
> Thanks! I gave it a try but we still have the waiting for mmc issue.

Yes, it was a long shot, but definitely something that needed fixing.

> Hm. Maybe we need a different test strategy.
> 
> Boot with non-dma MMC driver and try to use DMA for something else after
> successful boot. Maybe a dummy driver which just tries to copy bytes around
> which can be loaded through modprobe from the command line?
> 
> Then we can easily inspect register values and activities of the isolated
> driver and how it interacts with the DMA controller registers.

Yes, this was effectively what I was doing in my own environment. Just 
scheduling some memory-to-memory transfers via DMA would be informative.

Paul