On Tue, 2018-01-16 at 04:13 +0100, Ingo Molnar wrote: > * Andy Shevchenko <andriy.shevche...@linux.intel.com> wrote: > > > If user supplied serial base address via kernel command line and > > value > > is higher than IO space limit (64k boundary), assume for now that > > MMIO > > byte access is required. > > > > Later we might expand or modify this if needed. > > Is this a standard pattern for serial code configuration values?
I didn't get what you meant under "standard" here. IO space limit comes from generic io.h header and AFAIU is a hardware limitation (outN (%dx), ...; inX (%dx); dx is 16 bit register). Using mmio8 out of the IO space is dictated by the (modern) x86 platforms with non-standard (okay, high speed) UART location in address space. -- Andy Shevchenko <andriy.shevche...@linux.intel.com> Intel Finland Oy
