If the device node is not found or the of_iomap() failed, calling scu_enable would not be safe and could lead to an undefined system state. So warn in both failure paths before returning.
Signed-off-by: Nicholas Mc Guire <hof...@osadl.org> Link: http://lkml.org/lkml/2018/7/16/219 Fixes: commit 65ebcc115889 ("ARM: sti: Add STiH415 SOC support") --- V2: replacement of WARN_ON() by a meaningful pr_err as suggested by Patrice CHOTARD <patrice.chot...@st.com>. Problem was found by an experimental coccinelle script Patch was compile tested with: multi_v7_defconfig (implies CONFIG_ARCH_STI=y, CONFIG_SMP=y) (with one sparse warning unrelated to the proposed change) Patch is against 4.18-rc4 (localversion-next is next-20180716) arch/arm/mach-sti/platsmp.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/arch/arm/mach-sti/platsmp.c b/arch/arm/mach-sti/platsmp.c index 231f19e..530e9a5 100644 --- a/arch/arm/mach-sti/platsmp.c +++ b/arch/arm/mach-sti/platsmp.c @@ -107,12 +107,22 @@ static void __init sti_smp_prepare_cpus(unsigned int max_cpus) np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu"); - if (np) { - scu_base = of_iomap(np, 0); - scu_enable(scu_base); - of_node_put(np); + if (!np) { + pr_err("SCU not found at %s:%s():%d\n", + __FILE__, __func__, __LINE__); + return; } + scu_base = of_iomap(np, 0); + of_node_put(np); + if (!scu_base) { + pr_err("SCU remap failed at %s:%s():%d\n", + __FILE__, __func__, __LINE__); + return; + } + + scu_enable(scu_base); + if (max_cpus <= 1) return; -- 2.1.4
