[PATCH] ARM: vexpress: spc: fix uniprocessor initialization

From: Arnd Bergmann
Date: Tue Mar 23 2021 - 08:58:02 EST


From: Arnd Bergmann <arnd@xxxxxxxx>

When CONFIG_SMP is disabled, topology_physical_package_id()
returns -1 and gcc notices undefined behavior:

arch/arm/mach-versatile/spc.c: In function 've_spc_clk_init':
arch/arm/mach-versatile/spc.c:583:21: error: array subscript -1 is below array bounds of 'bool[2]' {aka '_Bool[2]'} [-Werror=array-bounds]
583 | if (init_opp_table[cluster])
| ~~~~~~~~~~~~~~^~~~~~~~~
arch/arm/mach-versatile/spc.c:556:7: note: while referencing 'init_opp_table'
556 | bool init_opp_table[MAX_CLUSTERS] = { false };
| ^~~~~~~~~~~~~~

It's not clear to me what the correct behavior should be, but
it seems safe to just not continue with the initialization.

Fixes: 2a76352ad2cc ("ARM: vexpress: Set-up shared OPP table instead of individual for each CPU")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
arch/arm/mach-versatile/spc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/mach-versatile/spc.c b/arch/arm/mach-versatile/spc.c
index 1da11bdb1dfb..1c6500c4e6a1 100644
--- a/arch/arm/mach-versatile/spc.c
+++ b/arch/arm/mach-versatile/spc.c
@@ -580,7 +580,7 @@ static int __init ve_spc_clk_init(void)
}

cluster = topology_physical_package_id(cpu_dev->id);
- if (init_opp_table[cluster])
+ if (cluster < 0 || init_opp_table[cluster])
continue;

if (ve_init_opp_table(cpu_dev))
--
2.29.2