ARM: 9006/1: uncompress: Wait for ready and busy in debug prints

For some platforms such as Qualcomm we need to wait for the
UART to be ready before writing characters to the UART
in the same manner as the macro in debug.S used with the
main "Uncompressing Linux ..." text. Pass an extra temporary
variable to writeb and make it call waituarttxrdy and
busyuart just like the other decomression messages.

Optionally it will also call waituartcts if and only if
CONFIG_DEBUG_UART_FLOW_CONTROL is selected.

After this the decompression debug messages work fine on
Qualcomm platforms if you compile head.S with -DDEBUG.

Cc: Nicolas Pitre <nico@fluxnic.net>
Cc: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

arch/arm/boot/compressed/head.S

@@ -28,19 +28,19 @@
 #if defined(CONFIG_CPU_V6) || defined(CONFIG_CPU_V6K) || defined(CONFIG_CPU_V7)
 		.macro	loadsp, rb, tmp1, tmp2
 		.endm
-		.macro	writeb, ch, rb
+		.macro	writeb, ch, rb, tmp
 		mcr	p14, 0, \ch, c0, c5, 0
 		.endm
 #elif defined(CONFIG_CPU_XSCALE)
 		.macro	loadsp, rb, tmp1, tmp2
 		.endm
-		.macro	writeb, ch, rb
+		.macro	writeb, ch, rb, tmp
 		mcr	p14, 0, \ch, c8, c0, 0
 		.endm
 #else
 		.macro	loadsp, rb, tmp1, tmp2
 		.endm
-		.macro	writeb, ch, rb
+		.macro	writeb, ch, rb, tmp
 		mcr	p14, 0, \ch, c1, c0, 0
 		.endm
 #endif
@@ -49,8 +49,13 @@
 
 #include CONFIG_DEBUG_LL_INCLUDE
 
-		.macro	writeb,	ch, rb
+		.macro	writeb,	ch, rb, tmp
+#ifdef CONFIG_DEBUG_UART_FLOW_CONTROL
+		waituartcts \tmp, \rb
+#endif
+		waituarttxrdy \tmp, \rb
 		senduart \ch, \rb
+		busyuart \tmp, \rb
 		.endm
 
 #if defined(CONFIG_ARCH_SA1100)
@@ -1326,7 +1331,7 @@ puts:		loadsp	r3, r2, r1
 1:		ldrb	r2, [r0], #1
 		teq	r2, #0
 		moveq	pc, lr
-2:		writeb	r2, r3
+2:		writeb	r2, r3, r1
 		mov	r1, #0x00020000
 3:		subs	r1, r1, #1
 		bne	3b