Re: [PATCH v2 1/2] clocksource: arm_arch_timer: Use stable count reader in erratum sne

[zhukeqian]

Hi Marc,

On 2020/12/3 22:58, Marc Zyngier wrote:
> On 2020-08-18 04:28, Keqian Zhu wrote:
>> In commit 0ea415390cd3 ("clocksource/arm_arch_timer: Use 
>> arch_timer_read_counter
>> to access stable counters"), we separate stable and normal count reader to 
>> omit
>> unnecessary overhead on systems that have no timer erratum.
>>
>> However, in erratum_set_next_event_tval_generic(), count reader becomes 
>> normal
>> reader. This converts it to stable reader.
>>
>> Fixes: 0ea415390cd3 ("clocksource/arm_arch_timer: Use
>>arch_timer_read_counter to access stable counters")
> 
> On a single line.
Addressed. Thanks.

> 
>> Signed-off-by: Keqian Zhu 
>> ---
>>  drivers/clocksource/arm_arch_timer.c | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/clocksource/arm_arch_timer.c
>> b/drivers/clocksource/arm_arch_timer.c
>> index 6c3e841..777d38c 100644
>> --- a/drivers/clocksource/arm_arch_timer.c
>> +++ b/drivers/clocksource/arm_arch_timer.c
>> @@ -396,10 +396,10 @@ static void
>> erratum_set_next_event_tval_generic(const int access, unsigned long
>>  ctrl &= ~ARCH_TIMER_CTRL_IT_MASK;
>>
>>  if (access == ARCH_TIMER_PHYS_ACCESS) {
>> -cval = evt + arch_counter_get_cntpct();
>> +cval = evt + arch_counter_get_cntpct_stable();
>>  write_sysreg(cval, cntp_cval_el0);
>>  } else {
>> -cval = evt + arch_counter_get_cntvct();
>> +cval = evt + arch_counter_get_cntvct_stable();
>>  write_sysreg(cval, cntv_cval_el0);
>>  }
> 
> With that fixed:
> 
> Acked-by: Marc Zyngier 
> 
> This should go via the clocksource tree.
Added Cc to it's maintainers, thanks.

> 
> Thanks,
> 
> M.
Cheers,
Keqian

Re: [PATCH v2 1/2] clocksource: arm_arch_timer: Use stable count reader in erratum sne

[Marc Zyngier]

On 2020-08-18 04:28, Keqian Zhu wrote:
In commit 0ea415390cd3 ("clocksource/arm_arch_timer: Use 
arch_timer_read_counter
to access stable counters"), we separate stable and normal count reader 
to omit

unnecessary overhead on systems that have no timer erratum.

However, in erratum_set_next_event_tval_generic(), count reader becomes 
normal

reader. This converts it to stable reader.

Fixes: 0ea415390cd3 ("clocksource/arm_arch_timer: Use
   arch_timer_read_counter to access stable counters")


On a single line.


Signed-off-by: Keqian Zhu 
---
 drivers/clocksource/arm_arch_timer.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/clocksource/arm_arch_timer.c
b/drivers/clocksource/arm_arch_timer.c
index 6c3e841..777d38c 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -396,10 +396,10 @@ static void
erratum_set_next_event_tval_generic(const int access, unsigned long
ctrl &= ~ARCH_TIMER_CTRL_IT_MASK;

if (access == ARCH_TIMER_PHYS_ACCESS) {
-   cval = evt + arch_counter_get_cntpct();
+   cval = evt + arch_counter_get_cntpct_stable();
write_sysreg(cval, cntp_cval_el0);
} else {
-   cval = evt + arch_counter_get_cntvct();
+   cval = evt + arch_counter_get_cntvct_stable();
write_sysreg(cval, cntv_cval_el0);
}


With that fixed:

Acked-by: Marc Zyngier 

This should go via the clocksource tree.

Thanks,

M.
--
Jazz is not dead. It just smells funny...