Hi John, CC linux-sh (SH-specific code) CC linux-renesas-soc (JFYI) On Mon, Nov 7, 2022 at 3:20 PM John Ogness <john.ogness@xxxxxxxxxxxxx> wrote: > When setting up the early console, the setup() callback of the > regular console is used. It is called manually before registering > the early console instead of providing a setup() callback for the > early console. This is probably because the early setup needs a > different @options during the early stage. > > The issue here is that the setup() callback is called without the > console_list_lock held and functions such as uart_set_options() > expect that. > > Rather than manually calling the setup() function before registering, > provide an early console setup() callback that will use the different > early options. This ensures that the error checking, ordering, and > locking context when setting up the early console are correct. > > Note that technically the current implementation works because it is > only used in early boot. And since the early console setup is > performed before registering, it cannot race with anything and thus > does not need any locking. However, longterm maintenance is easier > when drivers rely on the subsystem API rather than manually > implementing steps that could cause breakage in the future. > > 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 > @@ -3054,15 +3054,26 @@ static struct console serial_console = { > }; > > #ifdef CONFIG_SUPERH > +static char early_serial_buf[32]; > + > +static int early_serial_console_setup(struct console *co, char *options) > +{ > + WARN_ON(options); > + /* > + * Use @early_serial_buf because @options will always be > + * NULL at this early stage. > + */ > + return serial_console_setup(co, early_serial_buf); > +} > + > static struct console early_serial_console = { > .name = "early_ttySC", > .write = serial_console_write, > + .setup = early_serial_console_setup, > .flags = CON_PRINTBUFFER, > .index = -1, > }; > > -static char early_serial_buf[32]; > - > static int sci_probe_earlyprintk(struct platform_device *pdev) > { > const struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev); > @@ -3074,8 +3085,6 @@ static int sci_probe_earlyprintk(struct platform_device *pdev) > > sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true); > > - serial_console_setup(&early_serial_console, early_serial_buf); > - > if (!strstr(early_serial_buf, "keep")) > early_serial_console.flags |= CON_BOOT; > > -- > 2.30.2 LGTM, so Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> 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