On Fri, 2024-11-22 at 07:18 -0800, Guenter Roeck wrote: > On Fri, Apr 05, 2024 at 05:29:24PM +0200, Niklas Schnelle wrote: > > In a future patch HAS_IOPORT=n will disable inb()/outb() and friends at > > compile time. We thus need to add HAS_IOPORT as dependency for those > > drivers using them unconditionally. For 8250 based drivers some support > > MMIO only use so fence only the parts requiring I/O ports. > > > > Co-developed-by: Arnd Bergmann <arnd@xxxxxxxxxx> > > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxxxx> > > Signed-off-by: Niklas Schnelle <schnelle@xxxxxxxxxxxxx> > ... > > @@ -422,10 +443,12 @@ static void set_io_from_upio(struct uart_port *p) > > up->dl_write = default_serial_dl_write; > > > > + default: > > + WARN(1, "Unsupported UART type %x\n", p->iotype); > > So, according to this patch, the serial uart on microblaze, nios2, > openrisc, xtensa, and possibly others is not or no longer supported. > > WARNING: CPU: 0 PID: 0 at drivers/tty/serial/8250/8250_port.c:470 serial8250_set_defaults+0x1a8/0x22c > Unsupported UART type 0 > > Any special reason ? > > Guenter So according to the warning the p->iotype is 0 which is UPIO_PORT. For UPIO_PORT the switch above the WARN would pick io_serial_in() and io_serial_out() as handlers. These use inb() respectively outb() to access the serial so I don't see how they would work with !HAS_IOPORT and it most definitely won't work for s390. Now for Microblaze Kconfig says to select HAS_IOPORT if PCI so I'd assume that it can use inb()/outb() and maybe the PCI requirement is not correct if this isn't a PCI device and it used to work with inb()/outb()? For nios2, openrisc, and xtensa they don't select HAS_IOPORT so either it really won't work anyway or they should select it. Can you tell us more about the devices involved where you saw this? Thanks, Niklas
