* Paolo Bonzini (pbonz...@redhat.com) wrote:
> Otherwise, a serial port can get stuck if it is migrated while flow control
> is in effect.
>
> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
> ---
> hw/char/serial.c | 16 ++++++++++++++--
> include/hw/char/serial.h | 1 +
> 2 files changed, 15 insertions(+), 2 deletions(-)
>
> diff --git a/hw/char/serial.c b/hw/char/serial.c
> index e65e9e0..6f0a49e 100644
> --- a/hw/char/serial.c
> +++ b/hw/char/serial.c
> @@ -639,8 +639,20 @@ static int serial_post_load(void *opaque, int version_id)
> if (s->thr_ipending == -1) {
> s->thr_ipending = ((s->iir & UART_IIR_ID) == UART_IIR_THRI);
> }
> - if (s->tsr_retry > MAX_XMIT_RETRY) {
> - s->tsr_retry = MAX_XMIT_RETRY;
Why remove the check you just added?
> +
> + if (s->tsr_retry > 0) {
> + /* tsr_retry > 0 implies LSR.TEMT = 0 (transmitter not empty). */
> + if (s->lsr & UART_LSR_TEMT) {
> + return -1;
> + }
> +
> + assert(s->watch_tag == 0);
> + s->watch_tag = qemu_chr_fe_add_watch(s->chr, G_IO_OUT|G_IO_HUP,
> serial_xmit, s);
> + } else {
> + /* tsr_retry == 0 implies LSR.TEMT = 1 (transmitter empty). */
> + if (!(s->lsr & UART_LSR_TEMT)) {
> + return -1;
If you're failing migration (-1) then please error_report to say why
so when someone hits it I can immediately see why.
Dave
> + }
> }
>
> s->last_break_enable = (s->lcr >> 6) & 1;
> diff --git a/include/hw/char/serial.h b/include/hw/char/serial.h
> index ef90615..2ab835c 100644
> --- a/include/hw/char/serial.h
> +++ b/include/hw/char/serial.h
> @@ -56,6 +56,7 @@ struct SerialState {
> int it_shift;
> int baudbase;
> unsigned tsr_retry;
> + unsigned watch_tag;
> uint32_t wakeup;
>
> /* Time when the last byte was successfully sent out of the tsr */
> --
> 2.5.5
>
>
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
