From 332349518f1958b0bc1ae3febc2e4f75f214d255 Mon Sep 17 00:00:00 2001 From: Ben Dooks Date: Sun, 23 Dec 2007 03:09:34 +0100 Subject: [PATCH] [ARM] 4731/1: S3C2412: Check for incomplete sleep Check if the sleep command returns due to a pending interrupt in the standby unit. If this happens, try and ack the IRQ before re-trying the resume. It is currently unclear whether the resume can be backed out of at this stage as this could cause a problem with level based interrupts. Signed-off-by: Ben Dooks Signed-off-by: Russell King --- arch/arm/mach-s3c2412/Makefile | 2 +- arch/arm/mach-s3c2412/pm.c | 17 ++------- arch/arm/mach-s3c2412/sleep.S | 68 ++++++++++++++++++++++++++++++++++ 3 files changed, 72 insertions(+), 15 deletions(-) create mode 100644 arch/arm/mach-s3c2412/sleep.S diff --git a/arch/arm/mach-s3c2412/Makefile b/arch/arm/mach-s3c2412/Makefile index f8e011691b31..7b782c7df7b4 100644 --- a/arch/arm/mach-s3c2412/Makefile +++ b/arch/arm/mach-s3c2412/Makefile @@ -13,7 +13,7 @@ obj-$(CONFIG_CPU_S3C2412) += s3c2412.o obj-$(CONFIG_CPU_S3C2412) += irq.o obj-$(CONFIG_CPU_S3C2412) += clock.o obj-$(CONFIG_S3C2412_DMA) += dma.o -obj-$(CONFIG_S3C2412_PM) += pm.o +obj-$(CONFIG_S3C2412_PM) += pm.o sleep.o # Machine support diff --git a/arch/arm/mach-s3c2412/pm.c b/arch/arm/mach-s3c2412/pm.c index 974ffb130479..d4ffb2d98076 100644 --- a/arch/arm/mach-s3c2412/pm.c +++ b/arch/arm/mach-s3c2412/pm.c @@ -33,6 +33,8 @@ #include +extern void s3c2412_sleep_enter(void); + static void s3c2412_cpu_suspend(void) { unsigned long tmp; @@ -43,20 +45,7 @@ static void s3c2412_cpu_suspend(void) tmp |= S3C2412_PWRCFG_STANDBYWFI_SLEEP; __raw_writel(tmp, S3C2412_PWRCFG); - /* issue the standby signal into the pm unit. Note, we - * issue a write-buffer drain just in case */ - - tmp = 0; - - asm("b 1f\n\t" - ".align 5\n\t" - "1:\n\t" - "mcr p15, 0, %0, c7, c10, 4\n\t" - "mcr p15, 0, %0, c7, c0, 4" :: "r" (tmp)); - - /* we should never get past here */ - - panic("sleep resumed to originator?"); + s3c2412_sleep_enter(); } static void s3c2412_pm_prepare(void) diff --git a/arch/arm/mach-s3c2412/sleep.S b/arch/arm/mach-s3c2412/sleep.S new file mode 100644 index 000000000000..db32cac4199a --- /dev/null +++ b/arch/arm/mach-s3c2412/sleep.S @@ -0,0 +1,68 @@ +/* linux/arch/arm/mach-s3c2412/sleep.S + * + * Copyright (c) 2007 Simtec Electronics + * Ben Dooks + * + * S3C2412 Power Manager low-level sleep support + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA +*/ + +#include +#include +#include +#include + +#include + + .text + + .global s3c2412_sleep_enter + +s3c2412_sleep_enter: + mov r0, #0 /* argument for coprocessors */ + ldr r1, =S3C2410_INTPND + ldr r2, =S3C2410_SRCPND + ldr r3, =S3C2410_EINTPEND + + teq r0, r0 + bl s3c2412_sleep_enter1 + teq pc, r0 + bl s3c2412_sleep_enter1 + + .align 5 + + /* this is called twice, first with the Z flag to ensure that the + * instructions have been loaded into the cache, and the second + * time to try and suspend the system. + */ +s3c2412_sleep_enter1: + mcr p15, 0, r0, c7, c10, 4 + mcrne p15, 0, r0, c7, c0, 4 + + /* if we return from here, it is because an interrupt was + * active when we tried to shutdown. Try and ack the IRQ and + * retry, as simply returning causes the system to lock. + */ + + ldrne r9, [ r1 ] + strne r9, [ r1 ] + ldrne r9, [ r2 ] + strne r9, [ r2 ] + ldrne r9, [ r3 ] + strne r9, [ r3 ] + bne s3c2412_sleep_enter1 + + mov pc, r14