On Wed, Apr 13, 2016 at 06:15:46AM +0000, Miod Vallat wrote: > > It should be latched, at least on modern 16550-like UARTs. From > > a PC16550D datasheet: > > Keep in mind that com(4) is intended to support 16450 chips, which have > no FIFO. I believe that the current ordering of the operations is needed > to correctly support them, so you might want to decide at runtime where > to unmask this based upon whether the chip has a working FIFO or not.
In other words, some UARTs might not raise the interrupt then? Well, perhaps it is better to leave com(4) untouched and just suppress the spurious interrupt message in case of octeon UART interrupts. The message appears every time when comstart() is run by a secondary CPU if FIFOs are enabled.
