On Tue, 18 Oct 2022, Martin Hundebøll wrote:
> The logic to find unused ports when registering new 8250 uart ports
> searches only up to CONFIG_SERIAL_8250_RUNTIME_UARTS, which forces users
> of external 8250 ports to increase the number of runtime ports
> artificially.
>
> Fix this by initializing each allocated port structure with basic
> settings like line number and uart operation callbacks, and by searching
> the entire array of allocated ports to find an unused one.
So nr_uarts no longer means "Maximum number of UARTs supported." ?
Perhaps it should be reworded too.
--
i.
> Signed-off-by: Martin Hundebøll <martin@xxxxxxxxxx>
> ---
> drivers/tty/serial/8250/8250_core.c | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
> index 94fbf0add2ce..a166cc66e7d1 100644
> --- a/drivers/tty/serial/8250/8250_core.c
> +++ b/drivers/tty/serial/8250/8250_core.c
> @@ -500,7 +500,7 @@ static void __init serial8250_isa_init_ports(void)
> if (nr_uarts > UART_NR)
> nr_uarts = UART_NR;
>
> - for (i = 0; i < nr_uarts; i++) {
> + for (i = 0; i < UART_NR; i++) {
> struct uart_8250_port *up = &serial8250_ports[i];
> struct uart_port *port = &up->port;
>
> @@ -926,15 +926,16 @@ static struct uart_8250_port *serial8250_find_match_or_unused(const struct uart_
>
> /* try line number first if still available */
> i = port->line;
> - if (i < nr_uarts && serial8250_ports[i].port.type == PORT_UNKNOWN &&
> + if (i < UART_NR && serial8250_ports[i].port.type == PORT_UNKNOWN &&
> serial8250_ports[i].port.iobase == 0)
> return &serial8250_ports[i];
> +
> /*
> * We didn't find a matching entry, so look for the first
> * free entry. We look for one which hasn't been previously
> * used (indicated by zero iobase).
> */
> - for (i = 0; i < nr_uarts; i++)
> + for (i = 0; i < UART_NR; i++)
> if (serial8250_ports[i].port.type == PORT_UNKNOWN &&
> serial8250_ports[i].port.iobase == 0)
> return &serial8250_ports[i];
> @@ -943,7 +944,7 @@ static struct uart_8250_port *serial8250_find_match_or_unused(const struct uart_
> * That also failed. Last resort is to find any entry which
> * doesn't have a real port associated with it.
> */
> - for (i = 0; i < nr_uarts; i++)
> + for (i = 0; i < UART_NR; i++)
> if (serial8250_ports[i].port.type == PORT_UNKNOWN)
> return &serial8250_ports[i];
>
>
