serial: core: Controller id cannot be negative

The controller id cannot be negative. Let's fix the ctrl_id in preparation
for adding port_id to fix the device name.

Fixes: 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM")
Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20230725054216.45696-2-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 6d58c57..201813d 100644 (file)
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -459,7 +459,7 @@ struct uart_port {
                                                struct serial_rs485 *rs485);
        int                     (*iso7816_config)(struct uart_port *,
                                                  struct serial_iso7816 *iso7816);
-       int                     ctrl_id;                /* optional serial core controller id */
+       unsigned int            ctrl_id;                /* optional serial core controller id */
        unsigned int            irq;                    /* irq number */
        unsigned long           irqflags;               /* irq flags  */
        unsigned int            uartclk;                /* base uart clock */