Re: [PATCH v2] sunxi: psci: Fix sunxi_power_switch on sun8i-r40 platform

qianfan
2022-05-14T05:09:42Z

在 2022/5/14 11:52, Chen-Yu Tsai 写道:
> Hi,
>
> On Sat, May 14, 2022 at 11:19 AM <qianfanguijin@163.com> wrote:
>> From: qianfan Zhao <qianfanguijin@163.com>
>>
>> linux system will die if we offline one of the cpu on R40 based board:
>> eg: echo 0 > /sys/devices/system/cpu/cpu3/online
>>
>> Fixed sunxi_power_switch based on allwinner lichee 3.10 kernel driver.
>>
>> Signed-off-by: qianfan Zhao <qianfanguijin@163.com>
> Please add a Fixes tag.
>
>> ---
>> v2 changes: Fix the commit message, the source code doesn't change.
>>
>> arch/arm/cpu/armv7/sunxi/psci.c | 24 +++++++++++++++++++-----
>> 1 file changed, 19 insertions(+), 5 deletions(-)
>>
>> diff --git a/arch/arm/cpu/armv7/sunxi/psci.c b/arch/arm/cpu/armv7/sunxi/psci.c
>> index 1ac50f558a..63186a9388 100644
>> --- a/arch/arm/cpu/armv7/sunxi/psci.c
>> +++ b/arch/arm/cpu/armv7/sunxi/psci.c
>> @@ -79,8 +79,7 @@ static void __secure __mdelay(u32 ms)
>> static void __secure clamp_release(u32 __maybe_unused *clamp)
>> {
>> #if defined(CONFIG_MACH_SUN6I) || defined(CONFIG_MACH_SUN7I) || \
>> - defined(CONFIG_MACH_SUN8I_H3) || \
>> - defined(CONFIG_MACH_SUN8I_R40)
>> + defined(CONFIG_MACH_SUN8I_H3)
>> u32 tmp = 0x1ff;
>> do {
>> tmp >>= 1;
>> @@ -88,15 +87,30 @@ static void __secure clamp_release(u32 __maybe_unused *clamp)
>> } while (tmp);
>>
>> __mdelay(10);
>> +#elif defined(CONFIG_MACH_SUN8I_R40)
>> + u8 i, tmp = 0xfe;
>> +
>> + for (i = 0; i < 5; i++) { /* 0xfe, 0xf8, 0xe0, 0x80, 0x00 */
>> + writel(tmp, clamp);
>> + tmp <<= 2;
>> + }
>> +
>> + while (0x00 != readl(clamp)) {
>> + ;
>> + }
>> #endif
>> }
>>
>> static void __secure clamp_set(u32 __maybe_unused *clamp)
>> {
>> #if defined(CONFIG_MACH_SUN6I) || defined(CONFIG_MACH_SUN7I) || \
>> - defined(CONFIG_MACH_SUN8I_H3) || \
>> - defined(CONFIG_MACH_SUN8I_R40)
>> + defined(CONFIG_MACH_SUN8I_H3)
>> writel(0xff, clamp);
>> +#elif defined(CONFIG_MACH_SUN8I_R40)
>> + writel(0xff, clamp);
>> + while (0xff != readl(clamp)) {
>> + ;
>> + }
>> #endif
>> }
>>
>> @@ -153,7 +167,7 @@ static void __secure sunxi_cpu_set_power(int cpu, bool on)
>>
>> sunxi_power_switch((void *)cpucfg + SUN8I_R40_PWR_CLAMP(cpu),
>> (void *)cpucfg + SUN8I_R40_PWROFF,
>> - on, 0);
>> + on, cpu);
> I think this is the only change that is needed. Looking again at the
> R40 user manual, the original code turned off core 0 regardless of
> which core was being brought down.
>
> Could you give that a try? The power clamp stuff shouldn't change
> much, as the end result is the same. The readback might make a
> difference, but if it does, it should be applied to all SoCs.
Just change the last params of sunxi_power_switch can also work fine.

diff --git a/arch/arm/cpu/armv7/sunxi/psci.c
b/arch/arm/cpu/armv7/sunxi/psci.c
index 1ac50f558a..ae21879e69 100644
--- a/arch/arm/cpu/armv7/sunxi/psci.c
+++ b/arch/arm/cpu/armv7/sunxi/psci.c
@@ -153,7 +153,7 @@ static void __secure sunxi_cpu_set_power(int cpu,
bool on)

sunxi_power_switch((void *)cpucfg + SUN8I_R40_PWR_CLAMP(cpu),
(void *)cpucfg + SUN8I_R40_PWROFF,
-                          on, 0);
+                          on, cpu);
}
#else /* ! CONFIG_MACH_SUN7I && ! CONFIG_MACH_SUN8I_R40 */
static void __secure sunxi_cpu_set_power(int cpu, bool on)

The readback might as same as __mdelay.

But I can't make sure the 0xfe, 0x80 ... 0x00 sequence number when
clame_release.
>
>
> Regards
> ChenYu
>
>> }
>> #else /* ! CONFIG_MACH_SUN7I && ! CONFIG_MACH_SUN8I_R40 */
>> static void __secure sunxi_cpu_set_power(int cpu, bool on)
>> --
>> 2.25.1
>>