On Mon, 2019-02-11 at 19:34 -0200, Fabio Estevam wrote: > Hi Trent, > > On Mon, Feb 11, 2019 at 6:44 PM Trent Piepho <tpiepho@xxxxxxxxxx> wrote: > > > I've had more time to test. > > > > Without DMA, I can reload my FPGA hundreds of times and get days of > > uptime using linux-next. > > > > With DMA, loading is unreliable. The higher the SPI speed, the less > > reliable it is. Unfortunately, it's hard to duplicate the problem with > > a small amount of data, and with a large amount of data I can't examine > > it in depth enough to determine if the problem is related to SPI bus > > timing or IMX sDMA sending the wrong bytes to the spi controller. > > > > Using DMA with SPI causes kernel panics. Not always immediately, but > > after using DMA it's a smaller of minutes before something crashes. > > The backtraces are all over the place and don't usually point back into > > SPI. It does seem like they usually hit something has allocated or is > > allocating DMA memory. > > Did you test with an external SDMA firmware or with the ROM SDMA firmware? > > Just trying to understand if the SDMA firmware plays a role on this > behavior or not. The ROM firmware only.
