Re: [PATCH] serial: core: Fix serial_base_match() after fixing controller port name

[Greg Kroah-Hartman]

On Wed, Aug 02, 2023 at 02:48:43PM +0300, Tony Lindgren wrote:
> While fixing DEVNAME to be more usable, I broke serial_base_match() as
> the ctrl and port prefix for device seemed unnecessary.
> 
> Let's fix the issue by checking against dev->type and drv->name.
> 
> Fixes: 1ef2c2df1199 ("serial: core: Fix serial core controller port name to show controller id")
> Reported-by: kernel test robot <oliver.sang@xxxxxxxxx>
> Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
> ---
>  drivers/tty/serial/serial_base.h     |  3 +++
>  drivers/tty/serial/serial_base_bus.c | 10 ++++++++--
>  drivers/tty/serial/serial_ctrl.c     |  2 +-
>  drivers/tty/serial/serial_port.c     |  2 +-
>  4 files changed, 13 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/tty/serial/serial_base.h b/drivers/tty/serial/serial_base.h
> --- a/drivers/tty/serial/serial_base.h
> +++ b/drivers/tty/serial/serial_base.h
> @@ -6,6 +6,9 @@
>   * Author: Tony Lindgren <tony@xxxxxxxxxxx>
>   */
>  
> +#define SERIAL_BASE_CTRL_NAME	"ctrl"
> +#define SERIAL_BASE_PORT_NAME	"port"
> +
>  #define to_serial_base_ctrl_device(d) container_of((d), struct serial_ctrl_device, dev)
>  #define to_serial_base_port_device(d) container_of((d), struct serial_port_device, dev)
>  
> diff --git a/drivers/tty/serial/serial_base_bus.c b/drivers/tty/serial/serial_base_bus.c
> --- a/drivers/tty/serial/serial_base_bus.c
> +++ b/drivers/tty/serial/serial_base_bus.c
> @@ -29,9 +29,15 @@ static const struct device_type serial_port_type = {
>  
>  static int serial_base_match(struct device *dev, struct device_driver *drv)
>  {
> -	int len = strlen(drv->name);
> +	if (dev->type == &serial_ctrl_type &&
> +	    !strncmp(SERIAL_BASE_CTRL_NAME, drv->name, 4))

maybe:
	    !strncmp(SERIAL_BASE_CTRL_NAME, drv->name, strlen(SERIAL_BASE_CTRL_NAME))

as "4" is a magic number :)


thanks,

greg k-h