Re: [PATCH] tty: serial: Replace deprecated PCI API

[Philipp Stanner <phasta@mailbox.org>]

On Wed, 2025-11-26 at 09:02 -0800, Guenter Roeck wrote:
> On 11/26/25 01:10, Philipp Stanner wrote:
> > pcim_iomap_table() is deprecated. Moreover, its special usage in 8250,
> > causes a WARN_ON to fire (in pcim_add_mapping_to_legacy_table()).
> > 
> > 8250's function serial8250_pci_setup_port() effectively maps the same
> > BAR multiple times and adds an offset to the start address. While
> > mapping and adding offsets is not a bug, it can be achieved in a far
> > more straightforward way by using the specialized function
> > pcim_iomap_range().
> > 
> > pcim_iomap_range() does not add the mapping addresses to the deprecated
> > iomap table - that's not a problem, however, because non of the users of
> > serial8250_pci_setup_port() uses pcim_iomap_table().
> > 
> > Replace the deprecated PCI functions with pcim_iomap_range().
> > 
> > Cc: Guenter Roeck <linux@roeck-us.net>
> > Link: https://lore.kernel.org/dri-devel/16cd212f-6ea0-471d-bf32-34f55d7292fe@roeck-us.net/
> > Signed-off-by: Philipp Stanner <phasta@kernel.org>
> > ---
> > @Guenther: Can you please test this? I hope it fixes your issue.
> 
> Yes, it does. Thanks a lot for fixing this!
> 
> Tested-by: Guenter Roeck <linux@roeck-us.net>

@Greg:
Can you apply this?

P.


> 
> > ---
> >   drivers/tty/serial/8250/8250_pcilib.c | 9 +++++----
> >   1 file changed, 5 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/tty/serial/8250/8250_pcilib.c b/drivers/tty/serial/8250/8250_pcilib.c
> > index d8d0ae0d7238..f98eb2ab1005 100644
> > --- a/drivers/tty/serial/8250/8250_pcilib.c
> > +++ b/drivers/tty/serial/8250/8250_pcilib.c
> > @@ -28,13 +28,14 @@ int serial8250_pci_setup_port(struct pci_dev *dev, struct uart_8250_port *port,
> >   		return -EINVAL;
> >   
> >   	if (pci_resource_flags(dev, bar) & IORESOURCE_MEM) {
> > -		if (!pcim_iomap(dev, bar, 0) && !pcim_iomap_table(dev))
> > -			return -ENOMEM;
> > -
> >   		port->port.iotype = UPIO_MEM;
> >   		port->port.iobase = 0;
> >   		port->port.mapbase = pci_resource_start(dev, bar) + offset;
> > -		port->port.membase = pcim_iomap_table(dev)[bar] + offset;
> > +
> > +		port->port.membase = pcim_iomap_range(dev, bar, offset, 0);
> > +		if (IS_ERR(port->port.membase))
> > +			return PTR_ERR(port->port.membase);
> > +
> >   		port->port.regshift = regshift;
> >   	} else if (IS_ENABLED(CONFIG_HAS_IOPORT)) {
> >   		port->port.iotype = UPIO_PORT;
>