2020-01-22 12:41:09

by Sergey Korolev

Subject: [PATCH] MIPS: sync-r4k: do slave counter synchronization with disabled HW interrupts

synchronise_count_slave() called with an enabled in mips_clockevent_init()
timer interrupt which may decrease synchronization precision.

Signed-off-by: Sergey Korolev <[email protected]>
---
arch/mips/kernel/sync-r4k.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/arch/mips/kernel/sync-r4k.c b/arch/mips/kernel/sync-r4k.c
index f2973ce87f53..abdd7aaa3311 100644
--- a/arch/mips/kernel/sync-r4k.c
+++ b/arch/mips/kernel/sync-r4k.c
@@ -90,6 +90,9 @@ void synchronise_count_master(int cpu)
void synchronise_count_slave(int cpu)
{
int i;
+ unsigned long flags;
+
+ local_irq_save(flags);

/*
* Not every cpu is online at the time this gets called,
@@ -113,5 +116,7 @@ void synchronise_count_slave(int cpu)
}
/* Arrange for an interrupt in a short while */
write_c0_compare(read_c0_count() + COUNTON);
+
+ local_irq_restore(flags);
}
#undef NR_LOOPS
--
2.20.1

2020-01-23 19:46:25

by Paul Burton

Subject: Re: [PATCH] MIPS: sync-r4k: do slave counter synchronization with disabled HW interrupts

Hello,

Sergey Korolev wrote:
> synchronise_count_slave() called with an enabled in mips_clockevent_init()
> timer interrupt which may decrease synchronization precision.

Applied to mips-next.

> commit 0956be29a96c
> https://git.kernel.org/mips/c/0956be29a96c
>
> Signed-off-by: Sergey Korolev <[email protected]>
> Signed-off-by: Paul Burton <[email protected]>

Thanks,
Paul

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