Re: [PATCH 6/9] serial: core: prevent irrelevant I/O infos display for UPIO_BUS

[Hugo Villeneuve]

On Fri, 24 Apr 2026 13:51:52 +0300 (EEST)
Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> wrote:

> On Thu, 23 Apr 2026, Hugo Villeneuve wrote:
> 
> > From: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>
> > 
> > It doesn't make sense to display irrelevant MMIO or legacy I/O information
> > for serial devices on I2C or SPI busses. Now that we have a separate I/O
> > type for these types of devices, prevent display of I/O information for
> > them. Using uart_iotype_*() functions to do so also addresses the now
> > invalid check for "iotype >= UPIO_MEM".
> > 
> > Signed-off-by: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>
> > ---
> >  drivers/tty/serial/serial_core.c | 50 ++++++++++++++++++----------------------
> >  1 file changed, 22 insertions(+), 28 deletions(-)
> > 
> > diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
> > index 0bfdb69817e4259681fbc4658c9a68200aa2b65f..42559eda6fc134de77c3a7b850d565ebdc89e216 100644
> > --- a/drivers/tty/serial/serial_core.c
> > +++ b/drivers/tty/serial/serial_core.c
> > @@ -2011,13 +2011,18 @@ static void uart_line_info(struct seq_file *m, struct uart_state *state)
> >  	if (!uport)
> >  		return;
> >  
> > -	mmio = uport->iotype >= UPIO_MEM;
> > -	seq_printf(m, "%u: uart:%s %s%08llX irq:%u",
> > -			uport->line, uart_type(uport),
> > -			mmio ? "mmio:0x" : "port:",
> > -			mmio ? (unsigned long long)uport->mapbase
> > -			     : (unsigned long long)uport->iobase,
> > -			uport->irq);
> > +	seq_printf(m, "%u: uart:%s", uport->line, uart_type(uport));
> > +
> > +	mmio = uart_iotype_mmio(uport->iotype);
> > +
> > +	if (mmio || uart_iotype_legacy_io(uport->iotype)) {
> > +		seq_printf(m, " %s%08llX",
> > +			   mmio ? "mmio:0x" : "port:",
> > +			   mmio ? (unsigned long long)uport->mapbase
> > +			   : (unsigned long long)uport->iobase);
> 
> This should align to ?

Ok, my auto-indent is not working for that.

Will change it to:
    seq_printf(m, " %s%08llX", mmio ? "mmio:0x" : "port:",
               mmio ? (unsigned long long)uport->mapbase
                    : (unsigned long long)uport->iobase);

> 
> > +	}
> > +
> > +	seq_printf(m, "irq:%u", uport->irq);
> >  
> >  	if (uport->type == PORT_UNKNOWN) {
> >  		seq_putc(m, '\n');
> > @@ -2482,31 +2487,20 @@ EXPORT_SYMBOL(uart_resume_port);
> >  static inline void
> >  uart_report_port(struct uart_driver *drv, struct uart_port *port)
> >  {
> > -	char address[64];
> > +	char address[64] = "";
> >  
> > -	switch (port->iotype) {
> > -	case UPIO_PORT:
> > -		snprintf(address, sizeof(address), "I/O 0x%lx", port->iobase);
> > -		break;
> > -	case UPIO_HUB6:
> > +	if (uart_iotype_mmio(port->iotype))
> >  		snprintf(address, sizeof(address),
> > -			 "I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
> > -		break;
> > -	case UPIO_MEM:
> > -	case UPIO_MEM16:
> > -	case UPIO_MEM32:
> > -	case UPIO_MEM32BE:
> > -	case UPIO_AU:
> > -	case UPIO_TSI:
> > -		snprintf(address, sizeof(address),
> > -			 "MMIO 0x%llx", (unsigned long long)port->mapbase);
> > -		break;
> > -	default:
> > -		strscpy(address, "*unknown*", sizeof(address));
> > -		break;
> > +			 " at MMIO 0x%llx", (unsigned long long)port->mapbase);
> > +	else if (uart_iotype_legacy_io(port->iotype)) {
> > +		if (port->iotype == UPIO_PORT)
> > +			snprintf(address, sizeof(address), " at I/O 0x%lx", port->iobase);
> > +		else if (port->iotype == UPIO_HUB6)
> > +			snprintf(address, sizeof(address),
> > +				 " at I/O 0x%lx offset 0x%x", port->iobase, port->hub6);
> 
> Please use scnprintf() so we could perhaps one day get rid of snprintf() 
> entirely.

Ok will do.

> 
> >  	}
> >  
> > -	pr_info("%s%s%s at %s (irq = %u, base_baud = %u) is a %s\n",
> > +	pr_info("%s%s%s%s (irq = %u, base_baud = %u) is a %s\n",
> >  		port->dev ? dev_name(port->dev) : "",
> >  		port->dev ? ": " : "",
> >  		port->name,
> > 
> > 
> 
> -- 
>  i.
> 
> 


-- 
Hugo Villeneuve