On 05/06/2018 09:54, Sergio Lopez wrote: > Only retry on serial_xmit if qemu_chr_fe_write returns 0, as this is the > only recoverable error. > > Retrying with any other scenario, in addition to being a waste of CPU > cycles, can compromise the Guest stability if by the vCPU issuing the > write and the main loop thread are, by chance or explicit pinning, > running on the same pCPU. > > Previous discussion: > > https://lists.nongnu.org/archive/html/qemu-devel/2018-05/msg06998.html > > Signed-off-by: Sergio Lopez <s...@redhat.com> > --- > hw/char/serial.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/hw/char/serial.c b/hw/char/serial.c > index 605b0d0..6de6c29 100644 > --- a/hw/char/serial.c > +++ b/hw/char/serial.c > @@ -260,7 +260,7 @@ static void serial_xmit(SerialState *s) > if (s->mcr & UART_MCR_LOOP) { > /* in loopback mode, say that we just received a char */ > serial_receive1(s, &s->tsr, 1); > - } else if (qemu_chr_fe_write(&s->chr, &s->tsr, 1) != 1 && > + } else if (qemu_chr_fe_write(&s->chr, &s->tsr, 1) == 0 && > s->tsr_retry < MAX_XMIT_RETRY) { > assert(s->watch_tag == 0); > s->watch_tag = >
Queued, thanks to you and all those who participated in the discussion. Paolo
