From a2a571b74a3881963d8d09deb272d13afe5b49e3 Mon Sep 17 00:00:00 2001 From: Nicolas Ferre Date: Fri, 22 Oct 2010 18:55:39 +0200 Subject: [PATCH] AT91: pm: make sure that r0 is 0 when dealing with cache operations When using CP15 cache operations (c7), we make sure that Rd (r0) is actually 0 as ARM 926 TRM is saying. Signed-off-by: Nicolas Ferre --- arch/arm/mach-at91/pm.c | 9 +++++++-- arch/arm/mach-at91/pm.h | 3 ++- arch/arm/mach-at91/pm_slowclock.S | 1 + 3 files changed, 10 insertions(+), 3 deletions(-) diff --git a/arch/arm/mach-at91/pm.c b/arch/arm/mach-at91/pm.c index 87a31baf1cb3..dafbacc25eb1 100644 --- a/arch/arm/mach-at91/pm.c +++ b/arch/arm/mach-at91/pm.c @@ -261,8 +261,13 @@ static int at91_pm_enter(suspend_state_t state) * For ARM 926 based chips, this requirement is weaker * as at91sam9 can access a RAM in self-refresh mode. */ - asm("b 1f; .align 5; 1:"); - asm("mcr p15, 0, r0, c7, c10, 4"); /* drain write buffer */ + asm volatile ( "mov r0, #0\n\t" + "b 1f\n\t" + ".align 5\n\t" + "1: mcr p15, 0, r0, c7, c10, 4\n\t" + : /* no output */ + : /* no input */ + : "r0"); saved_lpr = sdram_selfrefresh_enable(); wait_for_interrupt_enable(); sdram_selfrefresh_disable(saved_lpr); diff --git a/arch/arm/mach-at91/pm.h b/arch/arm/mach-at91/pm.h index 2c4424bfa6c4..ce9a20699111 100644 --- a/arch/arm/mach-at91/pm.h +++ b/arch/arm/mach-at91/pm.h @@ -21,7 +21,8 @@ static inline u32 sdram_selfrefresh_enable(void) } #define sdram_selfrefresh_disable(saved_lpr) at91_sys_write(AT91_SDRAMC_LPR, saved_lpr) -#define wait_for_interrupt_enable() asm("mcr p15, 0, r0, c7, c0, 4") +#define wait_for_interrupt_enable() asm volatile ("mcr p15, 0, %0, c7, c0, 4" \ + : : "r" (0)) #elif defined(CONFIG_ARCH_AT91CAP9) #include diff --git a/arch/arm/mach-at91/pm_slowclock.S b/arch/arm/mach-at91/pm_slowclock.S index b6b00a1f6125..f7922a436172 100644 --- a/arch/arm/mach-at91/pm_slowclock.S +++ b/arch/arm/mach-at91/pm_slowclock.S @@ -124,6 +124,7 @@ ENTRY(at91_slow_clock) ldr r5, .at91_va_base_ramc1 /* Drain write buffer */ + mov r0, #0 mcr p15, 0, r0, c7, c10, 4 #ifdef CONFIG_ARCH_AT91RM9200 -- 2.20.1