On 10/04/2018 06:12 AM, Eugeniy Paltsev wrote: > Disabling and reconfiguring of IOC are quite a tricky actions because > nobody knows what happens if there're IOC-ahndled tarnsactions in flight > when we're disabling IOC. > > And the problem is external DMA masters [that were initialized and set > in a bootlaoder that was executed before we got here] might continue > to send data to memory even at this point and we have no way to prevent > that. > > That said it's much safer to not enable IOC at all anywhere before Linux > kernel. > > As we can build u-boot with IOC support (mostly for debugging purposes) > let's check that kernel was started with disabled IOC regardless of > our plans to use it or not. > > Also while I'm at it, replace hardcoded bits in ARC_REG_IO_COH_PARTIAL > and ARC_REG_IO_COH_ENABLE registers by definitions. > > Inspired by: https://lkml.org/lkml/2018/1/19/557 > Applied with updated changelog ! -Vineet
