Re: [Qemu-devel] [RFC PATCH v2 06/49] serial: fixing vmstate for save/restore

["Pavel Dovgaluk" <Pavel.Dovgaluk@ispras.ru>]

> -----Original Message-----
> From: Paolo Bonzini [mailto:paolo.bonzini@gmail.com] On Behalf Of Paolo Bonzini
> Sent: Monday, July 28, 2014 1:59 PM
> To: Pavel Dovgalyuk; qemu-devel@nongnu.org
> Cc: peter.maydell@linaro.org; peter.crosthwaite@xilinx.com; mark.burton@greensocs.com;
> real@ispras.ru; batuzovk@ispras.ru; fred.konrad@greensocs.com
> Subject: Re: [RFC PATCH v2 06/49] serial: fixing vmstate for save/restore
> 
> Il 17/07/2014 13:02, Pavel Dovgalyuk ha scritto:
> > -    .version_id = 3,
> > +    .version_id = 4,
> >      .minimum_version_id = 2,
> >      .pre_save = serial_pre_save,
> >      .post_load = serial_post_load,
> >      .fields = (VMStateField[]) {
> >          VMSTATE_UINT16_V(divider, SerialState, 2),
> >          VMSTATE_UINT8(rbr, SerialState),
> > +        VMSTATE_UINT8_V(thr, SerialState, 4),
> > +        VMSTATE_UINT8_V(tsr, SerialState, 4),
> >          VMSTATE_UINT8(ier, SerialState),
> >          VMSTATE_UINT8(iir, SerialState),
> >          VMSTATE_UINT8(lcr, SerialState),
> > @@ -613,6 +627,15 @@ const VMStateDescription vmstate_serial = {
> >          VMSTATE_UINT8(msr, SerialState),
> >          VMSTATE_UINT8(scr, SerialState),
> >          VMSTATE_UINT8_V(fcr_vmstate, SerialState, 3),
> > +        VMSTATE_INT32_V(thr_ipending, SerialState, 4),
> 
> Subsection, only migrated if it doesn't match "(s->iir & UART_IIR_ID) ==
> UART_IIR_THRI".

 thr_ipending is set here:
    if (s->lsr & UART_LSR_THRE) {
        s->lsr |= UART_LSR_TEMT;
        s->thr_ipending = 1;
        serial_update_irq(s);
    }

 serial_update_irq has several if-else branches. One of them sets tmp_iir = UART_IIR_THRI, as you said.
Couldn't be possible, that this branch will not be reached, because one of the previous ones will be executed?

Pavel Dovgalyuk