[PATCH] ARM: EXYNOS: Don't use LDREX and STREX after disabling cache coherency

[PATCH] ARM: EXYNOS: Don't use LDREX and STREX after disabling cache coherency

[Krzysztof Kozlowski]

During CPU shutdown the exynos_cpu_power_down() is called after
disabling cache coherency and it uses LDREX and STREX instructions (by
calling of_machine_is_compatible() -> kobject_get() -> kref_get()).

The LDREX and STREX should not be used after disabling the cache
coherency so just use soc_is_exynos().

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Fixes: adc548d77c22 ("ARM: EXYNOS: Use MCPM call-backs to support S2R on exynos5420")
Cc: <stable@vger.kernel.org>
Reported-by: Stephen Boyd <sboyd@codeaurora.org>
---
 arch/arm/mach-exynos/platsmp.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/arm/mach-exynos/platsmp.c b/arch/arm/mach-exynos/platsmp.c
index 7a1ebfeeeeb8..0abb7dff73ab 100644
--- a/arch/arm/mach-exynos/platsmp.c
+++ b/arch/arm/mach-exynos/platsmp.c
@@ -126,8 +126,7 @@ static inline void platform_do_lowpower(unsigned int cpu, int *spurious)
  */
 void exynos_cpu_power_down(int cpu)
 {
-	if (cpu == 0 && (of_machine_is_compatible("samsung,exynos5420") ||
-		of_machine_is_compatible("samsung,exynos5800"))) {
+	if (cpu == 0 && (soc_is_exynos5420() || soc_is_exynos5800())) {
 		/*
 		 * Bypass power down for CPU0 during suspend. Check for
 		 * the SYS_PWR_REG value to decide if we are suspending
-- 
1.9.1

Re: [PATCH] ARM: EXYNOS: Don't use LDREX and STREX after disabling cache coherency

[Stephen Boyd]

On 02/16/15 05:36, Krzysztof Kozlowski wrote:
> During CPU shutdown the exynos_cpu_power_down() is called after
> disabling cache coherency and it uses LDREX and STREX instructions (by
> calling of_machine_is_compatible() -> kobject_get() -> kref_get()).
>
> The LDREX and STREX should not be used after disabling the cache
> coherency so just use soc_is_exynos().
>
> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
> Fixes: adc548d77c22 ("ARM: EXYNOS: Use MCPM call-backs to support S2R on exynos5420")
> Cc: <stable@vger.kernel.org>
> Reported-by: Stephen Boyd <sboyd@codeaurora.org>
> ---

Looks good to me.

Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH] ARM: EXYNOS: Don't use LDREX and STREX after disabling cache coherency

[Kukjin Kim]

On 02/18/15 07:24, Stephen Boyd wrote:
> On 02/16/15 05:36, Krzysztof Kozlowski wrote:
>> During CPU shutdown the exynos_cpu_power_down() is called after
>> disabling cache coherency and it uses LDREX and STREX instructions (by
>> calling of_machine_is_compatible() -> kobject_get() -> kref_get()).
>>
>> The LDREX and STREX should not be used after disabling the cache
>> coherency so just use soc_is_exynos().
>>
>> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
>> Fixes: adc548d77c22 ("ARM: EXYNOS: Use MCPM call-backs to support S2R on exynos5420")
>> Cc: <stable@vger.kernel.org>
>> Reported-by: Stephen Boyd <sboyd@codeaurora.org>
>> ---
> 
> Looks good to me.
> 
> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
> 
Thanks for this fix, applied.

- Kukjin