From a500bd0238e0db994642ed7487de3e9e4b17dd3d Mon Sep 17 00:00:00 2001 From: Masayuki Ishikawa Date: Fri, 20 Nov 2020 13:45:53 +0900 Subject: [PATCH] arch: k210: Fix the pause handler for SMP Summary: - Apply the same logic added to cxd56_cpupause.c Impact: - SMP only Testing: - Tested with maix-bit:smp (QEMU) - Run smp and ostest Signed-off-by: Masayuki Ishikawa --- arch/risc-v/src/k210/k210_cpupause.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/arch/risc-v/src/k210/k210_cpupause.c b/arch/risc-v/src/k210/k210_cpupause.c index 88af783511..2eaa5737b6 100644 --- a/arch/risc-v/src/k210/k210_cpupause.c +++ b/arch/risc-v/src/k210/k210_cpupause.c @@ -205,6 +205,7 @@ int up_cpu_paused(int cpu) int riscv_pause_handler(int irq, void *c, FAR void *arg) { int cpu = up_cpu_index(); + int ret = OK; /* Clear machine software interrupt */ @@ -217,10 +218,21 @@ int riscv_pause_handler(int irq, void *c, FAR void *arg) if (spin_islocked(&g_cpu_paused[cpu])) { - return up_cpu_paused(cpu); + /* NOTE: up_cpu_paused() needs to be executed in a critical section + * to ensure that this CPU holds g_cpu_irqlock. However, adding + * a critical section in up_cpu_paused() is not a good idea, + * because it is also called in enter_critical_section() to break + * a deadlock + */ + + irqstate_t flags = enter_critical_section(); + + ret = up_cpu_paused(cpu); + + leave_critical_section(flags); } - return OK; + return ret; } /****************************************************************************