From 3c6bf7a324b8995b9c7d790c8d2abf0668f51551 Mon Sep 17 00:00:00 2001 From: Alexander Kochetkov Date: Thu, 3 Jul 2025 17:04:53 +0300 Subject: [PATCH] ARM: rockchip: fix kernel hang during smp initialization [ Upstream commit 7cdb433bb44cdc87dc5260cdf15bf03cc1cd1814 ] In order to bring up secondary CPUs main CPU write trampoline code to SRAM. The trampoline code is written while secondary CPUs are powered on (at least that true for RK3188 CPU). Sometimes that leads to kernel hang. Probably because secondary CPU execute trampoline code while kernel doesn't expect. The patch moves SRAM initialization step to the point where all secondary CPUs are powered down. That fixes rarely hangs on RK3188: [ 0.091568] CPU0: thread -1, cpu 0, socket 0, mpidr 80000000 [ 0.091996] rockchip_smp_prepare_cpus: ncores 4 Signed-off-by: Alexander Kochetkov Link: https://lore.kernel.org/r/20250703140453.1273027-1-al.kochet@gmail.com Signed-off-by: Heiko Stuebner Signed-off-by: Sasha Levin --- arch/arm/mach-rockchip/platsmp.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/arch/arm/mach-rockchip/platsmp.c b/arch/arm/mach-rockchip/platsmp.c index 649e0a54784c..246a525d1d26 100644 --- a/arch/arm/mach-rockchip/platsmp.c +++ b/arch/arm/mach-rockchip/platsmp.c @@ -279,11 +279,6 @@ static void __init rockchip_smp_prepare_cpus(unsigned int max_cpus) } if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9) { - if (rockchip_smp_prepare_sram(node)) { - of_node_put(node); - return; - } - /* enable the SCU power domain */ pmu_set_power_domain(PMU_PWRDN_SCU, true); @@ -316,11 +311,19 @@ static void __init rockchip_smp_prepare_cpus(unsigned int max_cpus) asm ("mrc p15, 1, %0, c9, c0, 2\n" : "=r" (l2ctlr)); ncores = ((l2ctlr >> 24) & 0x3) + 1; } - of_node_put(node); /* Make sure that all cores except the first are really off */ for (i = 1; i < ncores; i++) pmu_set_power_domain(0 + i, false); + + if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9) { + if (rockchip_smp_prepare_sram(node)) { + of_node_put(node); + return; + } + } + + of_node_put(node); } static void __init rk3036_smp_prepare_cpus(unsigned int max_cpus)