[PATCH v3 3/4] serial: 8250_dw: configure the Allwinner H616 UART

[Andy Shevchenko]

On Tue, Oct 27, 2026 at 09:21:57AM +0200, Andy Shevchenko wrote:
> On Sat, Oct 24, 2026 at 02:22:25PM -0600, James Hilliard wrote:

...

> > +static int dw8250_sunxi_set_rxtrig(struct uart_port *p, unsigned char bytes)
> > +{
> > +	struct uart_8250_port *up = up_to_u8250p(p);
> > +	unsigned int i;
> > +	int ret;
> > +
> > +	/* Use the nearest lower threshold, as the generic 8250 implementation does. */
> > +	for (i = 1; i < UART_FCR_R_TRIG_MAX_STATE; i++)
> > +		if (bytes < dw8250_sunxi_rxtrig_bytes(p, i))
> > +			break;
> 
> Can we provide an array of the possible values and deduplicate this loop?
> 
> drivers/tty/serial/8250/8250.h:
> 
> static inline int serial8250_bytes_to_fcr(unsigned char *rxtrig_bytes, unsigned char bytes)
> {
> 	for (unsigned int i = 1; i < UART_FCR_R_TRIG_MAX_STATE; i++) {
> 		if (bytes < rxtrig_bytes[i])
> 			/* Use the nearest lower value */
> 			return (--i) << UART_FCR_R_TRIG_SHIFT;
>         }
> 
>         return UART_FCR_R_TRIG_11;
> }
> 
> drivers/tty/serial/8250/8250_port.c:
> 
> static int bytes_to_fcr_rxtrig(struct uart_8250_port *up, unsigned char bytes)
> {
>         const struct serial8250_config *conf_type = &uart_config[up->port.type];

>         if (!conf_type->rxtrig_bytes[UART_FCR_R_TRIG_BITS(UART_FCR_R_TRIG_00)])
>                 return -EOPNOTSUPP;

Even this probably should be moved above as well.

> 	return serial8250_bytes_to_fcr(conf_type->rxtrig_bytes, bytes);
> }

> (this split should be done in a separate preparatory change).

-- 
With Best Regards,
Andy Shevchenko