Re: [PATCH] powerpc/xmon: Change printk() to pr_cont()

From: Michael Ellerman
Date: Fri Dec 04 2020 - 05:58:13 EST


Christophe Leroy <christophe.leroy@xxxxxxxxxx> writes:
> Since some time now, printk() adds carriage return, leading to
> unusable xmon output:
>
> [ 54.288722] sysrq: Entering xmon
> [ 54.292209] Vector: 0 at [cace3d2c]
> [ 54.292274] pc:
> [ 54.292331] c0023650

...

> diff --git a/arch/powerpc/xmon/nonstdio.c b/arch/powerpc/xmon/nonstdio.c
> index 5c1a50912229..9b0d85bff021 100644
> --- a/arch/powerpc/xmon/nonstdio.c
> +++ b/arch/powerpc/xmon/nonstdio.c
> @@ -178,7 +178,7 @@ void xmon_printf(const char *format, ...)
>
> if (n && rc == 0) {
> /* No udbg hooks, fallback to printk() - dangerous */
> - printk("%s", xmon_outbuf);
> + pr_cont("%s", xmon_outbuf);
> }

Ah OK, in the case where there's no udbg backend. We basically always
have a udbg backend on 64-bit, via hvc console. Which explains why we
haven't noticed it.

Will pick up the patch.

cheers