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

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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>
This commit is contained in:
Linus Walleij 2020-08-27 23:29:34 +01:00 committed by Russell King
parent 4df24fef09
commit 0b0c1dbd50
1 changed files with 10 additions and 5 deletions
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15
arch/arm/boot/compressed/head.S
View File

@ -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