Re: [PATCH 1/6] arm: zynq: platsmp: Fix CPU presence check

From: Sudeep KarkadaNagesha
Date: Thu Oct 31 2013 - 12:42:45 EST


Hi Soren,

On 31/10/13 16:10, Soren Brinkmann wrote:
> From: Peter Crosthwaite <peter.crosthwaite@xxxxxxxxxx>
>
> Fix an off-by-one error in the logic that checks if a CPU is present.
> The ncores variable is a count of cores while the cpu variable is a
> 0 based index. So if ncores == cpu, cpu is out of range. Fix this
> comparison so non-existent CPUs are not probed.
>

Not entirely related to this patch, I had found that zynq_smp_prepare_cpus is
setting cpu_present_mask which is redundant(CMIIW present == possible). I had
posted a patch[1] to remove that, consider including that in the series if you
think it make sense.

Regards,
Sudeep

[1] http://www.spinics.net/lists/arm-kernel/msg260734.html

> Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xxxxxxxxxx>
> Signed-off-by: Michal Simek <michal.simek@xxxxxxxxxx>
> ---
> arch/arm/mach-zynq/platsmp.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm/mach-zynq/platsmp.c b/arch/arm/mach-zynq/platsmp.c
> index 689fbbc3d9c8..2512624e657d 100644
> --- a/arch/arm/mach-zynq/platsmp.c
> +++ b/arch/arm/mach-zynq/platsmp.c
> @@ -39,7 +39,7 @@ int zynq_cpun_start(u32 address, int cpu)
> u32 trampoline_code_size = &zynq_secondary_trampoline_end -
> &zynq_secondary_trampoline;
>
> - if (cpu > ncores) {
> + if (cpu >= ncores) {
> pr_warn("CPU No. is not available in the system\n");
> return -1;
> }
>


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