[PATCH 3/3] ARM: early_printk: use printascii() rather than printch()

[Chris Brandt]

On Tuesday, October 31, 2017, Nicolas Pitre wrote:
> On Tue, 31 Oct 2017, Russell King - ARM Linux wrote:
> > On Tue, Oct 31, 2017 at 02:15:14PM -0400, Nicolas Pitre wrote:
> > > On Tue, 31 Oct 2017, Russell King - ARM Linux wrote:
> > > > So a printch('\n') produces "\n\r" on the UART.  If we're fixing
> > > > printascii() to emit "\r\n" instead of "\n\r" for a '\n', then
> > > > printch() should have the same fix, and should not truncate to
> > > > just '\n'.
> > >
> > > OK... That's easy to achieve, but is it desirable?
> >
> > Yes - remember, these are supposed to be usable from assembly,
> > and we really don't want to have the complexity of:
> >
> > 	mov	r0, #'\r'
> > 	bl	printch
> > 	mov	r0, #'\n'
> > 	bl	printch
> >
> > each time we want to begin a new line.
> 
> Fine with me.
> 
> diff --git a/arch/arm/kernel/debug.S b/arch/arm/kernel/debug.S
> index ea9646cc2a..01d746efff 100644
> --- a/arch/arm/kernel/debug.S
> +++ b/arch/arm/kernel/debug.S
> @@ -79,25 +79,28 @@ hexbuf:		.space 16
> 
>  ENTRY(printascii)
>  		addruart_current r3, r1, r2
> -		b	2f
> -1:		waituart r2, r3
> -		senduart r1, r3
> -		busyuart r2, r3
> -		teq	r1, #'\n'
> -		moveq	r1, #'\r'
> -		beq	1b
> -2:		teq	r0, #0
> +1:		teq	r0, #0
>  		ldrneb	r1, [r0], #1
>  		teqne	r1, #0
> -		bne	1b
> -		ret	lr
> +		reteq	lr
> +2:		teq     r1, #'\n'
> +		bne	3f
> +		mov	r1, '\r'
> +		waituart r2, r3
> +		senduart r1, r3
> +		busyuart r2, r3
> +		mov	r1, '\n'
> +3:		waituart r2, r3
> +		senduart r1, r3
> +		busyuart r2, r3
> +		b	1b
>  ENDPROC(printascii)
> 
>  ENTRY(printch)
>  		addruart_current r3, r1, r2
>  		mov	r1, r0
>  		mov	r0, #0
> -		b	1b
> +		b	2b
>  ENDPROC(printch)
> 
>  #ifdef CONFIG_MMU


This patch worked for me.
I get my carriage returns again.

Thanks.

Chris