From 0956be29a96c1ce879b6a8fad1cc61f53c140ec8 Mon Sep 17 00:00:00 2001 From: Sergey Korolev Date: Wed, 22 Jan 2020 15:39:08 +0300 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 Signed-off-by: Paul Burton Cc: linux-mips@vger.kernel.org Cc: Ralf Baechle Cc: James Hogan Cc: linux-kernel@vger.kernel.org --- 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