diff options
| -rw-r--r-- | hw/char/serial.c | 25 |
1 files changed, 23 insertions, 2 deletions
diff --git a/hw/char/serial.c b/hw/char/serial.c index af39e8f867..3442f47d36 100644 --- a/hw/char/serial.c +++ b/hw/char/serial.c @@ -644,8 +644,29 @@ 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; + + if (s->tsr_retry > 0) { + /* tsr_retry > 0 implies LSR.TEMT = 0 (transmitter not empty). */ + if (s->lsr & UART_LSR_TEMT) { + error_report("inconsistent state in serial device " + "(tsr empty, tsr_retry=%d", s->tsr_retry); + return -1; + } + + if (s->tsr_retry > MAX_XMIT_RETRY) { + s->tsr_retry = MAX_XMIT_RETRY; + } + + assert(s->watch_tag == 0); + s->watch_tag = qemu_chr_fe_add_watch(s->chr, G_IO_OUT|G_IO_HUP, + serial_watch_cb, s); + } else { + /* tsr_retry == 0 implies LSR.TEMT = 1 (transmitter empty). */ + if (!(s->lsr & UART_LSR_TEMT)) { + error_report("inconsistent state in serial device " + "(tsr not empty, tsr_retry=0"); + return -1; + } } s->last_break_enable = (s->lcr >> 6) & 1; |