Re: [PATCH tty v4 3/6] serial: sh-sci: Avoid deprecated UPF_CONS_FLOW

From: Geert Uytterhoeven

Date: Wed May 06 2026 - 08:54:41 EST


On Wed, 6 May 2026 at 14:39, Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
> On Wed, 6 May 2026 at 14:16, John Ogness <john.ogness@xxxxxxxxxxxxx> wrote:
> > Avoid setting the uart_port.flags deprecated UPF_CONS_FLOW bit if it
> > has been configured in the platform data. Use the new cons_flow
> > wrappers instead.
> >
> > Signed-off-by: John Ogness <john.ogness@xxxxxxxxxxxxx>
>
> Thanks for your patch!
>
> > --- a/drivers/tty/serial/sh-sci.c
> > +++ b/drivers/tty/serial/sh-sci.c
> > @@ -3369,9 +3369,12 @@ static int sci_init_single(struct platform_device *dev,
> > }
> >
> > port->type = SCI_PUBLIC_PORT_ID(p->type);
> > - port->flags = UPF_FIXED_PORT | UPF_BOOT_AUTOCONF | p->flags;
> > + port->flags = UPF_FIXED_PORT | UPF_BOOT_AUTOCONF |
> > + (p->flags & ~UPF_CONS_FLOW);
>
> This seems over-cautious to me.
> The last setter of p->flags was removed in commit 37744feebc086908
> ("sh: remove sh5 support") in v5.8. No platform data ever set the
> UPF_CONS_FLOW flag before. I would rather remove plat_sci_port.flags
> and this "| p->flags", so we don't have to care about UPF_CONS_FLOW
> in this driver at all.

I have sent a patch to remove it:
https://lore.kernel.org/20260506124643.128021-1-geert+renesas@xxxxxxxxx/

Builds on Renesas ARM/ARM64/RISCV/SH, and boots on QEMU
(rts7751)r2d.

>
> > port->fifosize = sci_port->params->fifosize;
> >
> > + uart_set_cons_flow_enabled(port, p->flags & UPF_CONS_FLOW);
> > +
> > if (p->type == PORT_SCI && !dev->dev.of_node) {
> > if (sci_port->reg_size >= 0x20)
> > port->regshift = 2;

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds