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* [PATCH] MIPS: sync-r4k: do slave counter synchronization with disabled HW interrupts
@ 2020-01-22 12:39 Sergey Korolev
  2020-01-23 19:44 ` Paul Burton
  0 siblings, 1 reply; 2+ messages in thread
From: Sergey Korolev @ 2020-01-22 12:39 UTC (permalink / raw)
  To: linux-mips
  Cc: s.korolev, Ralf Baechle, Paul Burton, James Hogan, linux-kernel

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

Signed-off-by: Sergey Korolev <s.korolev@ndmsystems.com>
---
 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


^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [PATCH] MIPS: sync-r4k: do slave counter synchronization with  disabled HW interrupts
  2020-01-22 12:39 [PATCH] MIPS: sync-r4k: do slave counter synchronization with disabled HW interrupts Sergey Korolev
@ 2020-01-23 19:44 ` Paul Burton
  0 siblings, 0 replies; 2+ messages in thread
From: Paul Burton @ 2020-01-23 19:44 UTC (permalink / raw)
  To: Sergey Korolev
  Cc: linux-mips, s.korolev, Ralf Baechle, Paul Burton, James Hogan,
	linux-kernel, linux-mips

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 <s.korolev@ndmsystems.com>
> Signed-off-by: Paul Burton <paulburton@kernel.org>

Thanks,
    Paul

[ This message was auto-generated; if you believe anything is incorrect
  then please email paulburton@kernel.org to report it. ]

^ permalink raw reply	[flat|nested] 2+ messages in thread

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