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

Hugo Villeneuve
2026-04-24T14:24:58Z

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

> On Thu, 23 Apr 2026, Hugo Villeneuve wrote:
>
> > From: Hugo Villeneuve <hvilleneuve@dimonoff.com>
> >
> > 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@dimonoff.com>
> > ---
> > 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