On Tue, Sep 11, 2018 at 03:21:34PM +0200, Paolo Bonzini wrote:
> On 01/09/2018 01:37, Guenter Roeck wrote:
> > The patch results in an unexpected DLL register value. Here is the
> > surrounding code from drivers/tty/serial/pxa.c:
> >
> > serial_out(up, UART_DLL, quot & 0xff); /* LS of divisor */
> >
> > /*
> > * work around Errata #75 according to Intel(R) PXA27x
> > * Processor Family Specification Update (Nov 2005)
> > */
> > dll = serial_in(up, UART_DLL);
> > WARN_ON(dll != (quot & 0xff)); // <-- warning
> >
> > Reverting the patch fixes the problem.
>
> I think it's a typo. Can you try this:
>
You are correct, the patch below fixes the problem.
Tested-by: Guenter Roeck <li...@roeck-us.net>
Thanks!
Guenter
> diff --git a/hw/char/serial.c b/hw/char/serial.c
> index 251f40fdac..02463e3388 100644
> --- a/hw/char/serial.c
> +++ b/hw/char/serial.c
> @@ -345,9 +345,9 @@ static void serial_ioport_write(void *opaque, hwaddr
> addr, uint64_t val,
> default:
> case 0:
> if (s->lcr & UART_LCR_DLAB) {
> - if (size == 2) {
> + if (size == 1) {
> s->divider = (s->divider & 0xff00) | val;
> - } else if (size == 4) {
> + } else {
> s->divider = val;
> }
> serial_update_parameters(s);
>
> Thanks,
>
> Paolo
