Re: [Qemu-devel] [PATCH v3 1/1] char/serial: Fix emptyness handling

[Paolo Bonzini]

Il 28/03/2014 12:43, Don Slutz ha scritto:
> Ping.  (Since this is a bug fix, I think it can go into 2.0)
>     -Don Slutz

I think the problem is that not many people understand the 8250 device 
model.  CCing someone who hopefully does...

Paolo

> On 03/18/14 12:29, Don Slutz wrote:
> > The commit 88c1ee73d3231c74ff90bcfc084a7589670ec244
> > char/serial: Fix emptyness check
> >
> > Still causes extra NULL byte(s) to be sent.
> >
> > So if the fifo is empty, do not send an extra NULL byte.
> >
> > Reviewed-by: Peter Crosthwaite <address@hidden>
> > Signed-off-by: Don Slutz <address@hidden>
> > ---
> > Changes V2 to v3
> >    Revert v2 changes
> >    Fix coding style issues.
> > Changes v1 to v2
> >    Do full state change on fifo8_is_empty.
> >
> >   hw/char/serial.c | 6 ++++--
> >   1 file changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git a/hw/char/serial.c b/hw/char/serial.c
> > index 6d3b5af..f4d167f 100644
> > --- a/hw/char/serial.c
> > +++ b/hw/char/serial.c
> > @@ -225,8 +225,10 @@ static gboolean serial_xmit(GIOChannel *chan,
> > GIOCondition cond, void *opaque)
> >         if (s->tsr_retry <= 0) {
> >           if (s->fcr & UART_FCR_FE) {
> > -            s->tsr = fifo8_is_empty(&s->xmit_fifo) ?
> > -                        0 : fifo8_pop(&s->xmit_fifo);
> > +            if (fifo8_is_empty(&s->xmit_fifo)) {
> > +                return FALSE;
> > +            }
> > +            s->tsr = fifo8_pop(&s->xmit_fifo);
> >               if (!s->xmit_fifo.num) {
> >                   s->lsr |= UART_LSR_THRE;
> >               }