On Tue, Feb 12, 2019 at 10:07 PM Trent Piepho <tpiepho@xxxxxxxxxx> wrote: > Tried SDMA firmware 4.2. Still broken. No apparent change. > > Get 4 cycle pause after each byte. > > And crash while/after using DMA. Clearly some sort of memory > corruption going on. Fortunately, it's very reliable that using DMA > almost immediately causes a problem and this is easy to reproduce. I > think that indicates it's either clobbers a lot of RAM, or consistently > manages to hit a very important location for kernel memory allocators. > > I've got an idea of where that might be happening that I'm looking > into. Ok, thanks for investigating this issue. > > I think it's reasonable to add the dma attributes, but put a check in > the spi-imx driver to disable DMA on imx7d at least. Something like this? http://dark-code.bulix.org/urfoh8-580174
