Hi Geert,
> -----Original Message-----
> From: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> Sent: Friday, April 21, 2023 10:38 AM
> To: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>; Jiri Slaby
> <jirislaby@xxxxxxxxxx>; Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx>; linux-
> serial@xxxxxxxxxxxxxxx; Prabhakar Mahadev Lad <prabhakar.mahadev-
> lad.rj@xxxxxxxxxxxxxx>; linux-renesas-soc@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH v4 4/5] tty: serial: sh-sci: Add support for tx end
> interrupt handling
>
> Hi Biju,
>
> On Wed, Apr 12, 2023 at 4:57 PM Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote:
> > As per the RZ/G2L users hardware manual (Rev.1.20 Sep, 2022), section
> > 23.3.7 Serial Data Transmission (Asynchronous Mode), it is mentioned
> > that, set the SCR.TIE bit to 0 and SCR.TEIE bit to 1, after the last
> > data to be transmitted are written to the TDR.
> >
> > This will generate tx end interrupt and in the handler set SCR.TE and
> > SCR.TEIE to 0.
> >
> > Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
>
> Thanks for your patch!
>
> > --- a/drivers/tty/serial/sh-sci.c
> > +++ b/drivers/tty/serial/sh-sci.c
> > @@ -860,9 +860,16 @@ static void sci_transmit_chars(struct uart_port
> > *port)
> >
> > if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
> > uart_write_wakeup(port);
> > - if (uart_circ_empty(xmit))
> > - sci_stop_tx(port);
> > + if (uart_circ_empty(xmit)) {
> > + if (port->type == PORT_SCI) {
> > + ctrl = serial_port_in(port, SCSCR);
> > + ctrl &= ~SCSCR_TIE;
> > + ctrl |= SCSCR_TEIE;
> > + serial_port_out(port, SCSCR, ctrl);
>
> Clearing SCSCR_TIE is already done in sci_stop_tx() below, so I think it
> would be better to just add
>
> if (port->type == PORT_SCI)
> ctrl |= SCSCR_TEIE
>
> to sci_stop_tx() instead.
I have tested this change and it works ok.
Cheers,
Biju
>
> > + }
> >
> > + sci_stop_tx(port);
> > + }
> > }
>
> The rest LGTM.
>
> Gr{oetje,eeting}s,
>
> Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-
> m68k.org
>
> 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
