Re: [Qemu-devel] [PATCH v2 1/4] hw/char: Implement nRF51 SoC UART

[Stefan Hajnoczi]

On Wed, Aug 8, 2018 at 10:07 PM, Julia Suvorova <address@hidden> wrote:
> +static uint64_t uart_read(void *opaque, hwaddr addr, unsigned int size)
> +{
> +    NRF51UARTState *s = NRF51_UART(opaque);
> +    uint64_t r;
> +
> +    if (!s->enabled) {
> +        return 0;
> +    }
> +
> +    switch (addr) {
> +    case A_UART_RXD:
> +        r = s->rx_fifo[s->rx_fifo_pos];
> +        if (s->rx_started && s->rx_fifo_len) {
> +            qemu_chr_fe_accept_input(&s->chr);

Should this be called after popping a byte from the rx fifo?  That way
.can_receive() will return true again.

> +static void nrf51_uart_realize(DeviceState *dev, Error **errp)
> +{
> +    NRF51UARTState *s = NRF51_UART(dev);
> +
> +    qemu_chr_fe_set_handlers(&s->chr, uart_can_receive, uart_receive,
> +                             uart_event, NULL, s, NULL, true);
> +}

unrealize() should set the handlers to NULL.  That way the device can
be removed without leaving callbacks registered.