diff options
| -rw-r--r-- | hw/char/serial.c | 26 |
1 files changed, 12 insertions, 14 deletions
diff --git a/hw/char/serial.c b/hw/char/serial.c index 8c42d03faf..9adb12667d 100644 --- a/hw/char/serial.c +++ b/hw/char/serial.c @@ -224,21 +224,23 @@ static gboolean serial_xmit(GIOChannel *chan, GIOCondition cond, void *opaque) SerialState *s = opaque; do { + assert(!(s->lsr & UART_LSR_TEMT)); if (s->tsr_retry <= 0) { + assert(!(s->lsr & UART_LSR_THRE)); + if (s->fcr & UART_FCR_FE) { - if (fifo8_is_empty(&s->xmit_fifo)) { - return FALSE; - } + assert(!fifo8_is_empty(&s->xmit_fifo)); s->tsr = fifo8_pop(&s->xmit_fifo); if (!s->xmit_fifo.num) { s->lsr |= UART_LSR_THRE; } - } else if ((s->lsr & UART_LSR_THRE)) { - return FALSE; } else { s->tsr = s->thr; s->lsr |= UART_LSR_THRE; - s->lsr &= ~UART_LSR_TEMT; + } + if ((s->lsr & UART_LSR_THRE) && !s->thr_ipending) { + s->thr_ipending = 1; + serial_update_irq(s); } } @@ -256,17 +258,13 @@ static gboolean serial_xmit(GIOChannel *chan, GIOCondition cond, void *opaque) } else { s->tsr_retry = 0; } + /* Transmit another byte if it is already available. It is only possible when FIFO is enabled and not empty. */ - } while ((s->fcr & UART_FCR_FE) && !fifo8_is_empty(&s->xmit_fifo)); + } while (!(s->lsr & UART_LSR_THRE)); s->last_xmit_ts = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); - - if (s->lsr & UART_LSR_THRE) { - s->lsr |= UART_LSR_TEMT; - s->thr_ipending = 1; - serial_update_irq(s); - } + s->lsr |= UART_LSR_TEMT; return FALSE; } @@ -323,10 +321,10 @@ static void serial_ioport_write(void *opaque, hwaddr addr, uint64_t val, fifo8_pop(&s->xmit_fifo); } fifo8_push(&s->xmit_fifo, s->thr); - s->lsr &= ~UART_LSR_TEMT; } s->thr_ipending = 0; s->lsr &= ~UART_LSR_THRE; + s->lsr &= ~UART_LSR_TEMT; serial_update_irq(s); if (s->tsr_retry <= 0) { serial_xmit(NULL, G_IO_OUT, s); |