Re: [PATCH 2/4] irqchip: bcm2836: Add SMP support for the 2836

2016-01-02 Thread Andrea Merello
Agreed.
This probably comes from the downstream code, I think.. But I agree
it's actually redundant.

Thank you for pointing this out.

On Sat, Jan 2, 2016 at 11:27 AM, Russell King - ARM Linux
 wrote:
> On Sat, Dec 26, 2015 at 01:47:22PM -0800, Eric Anholt wrote:
>> +int __init bcm2836_smp_boot_secondary(unsigned int cpu,
>> +   struct task_struct *idle)
>> +{
>> + unsigned long secondary_startup_phys =
>> + (unsigned long)virt_to_phys((void *)secondary_startup);
>> +
>> + dsb();
>> + writel(secondary_startup_phys,
>> +intc.base + LOCAL_MAILBOX3_SET0 + 16 * cpu);
>
> Please explain why you need this dsb() - I can't see a reason for it.
> writel() has a barrier internally prior to writing the register, and
> therefore I think the above dsb() is entirely redundant.
>
> --
> RMK's Patch system: http://www.arm.linux.org.uk/developer/patches/
> FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
> according to speedtest.net.
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Re: [PATCH 2/4] irqchip: bcm2836: Add SMP support for the 2836

2016-01-02 Thread Russell King - ARM Linux
On Sat, Dec 26, 2015 at 01:47:22PM -0800, Eric Anholt wrote:
> +int __init bcm2836_smp_boot_secondary(unsigned int cpu,
> +   struct task_struct *idle)
> +{
> + unsigned long secondary_startup_phys =
> + (unsigned long)virt_to_phys((void *)secondary_startup);
> +
> + dsb();
> + writel(secondary_startup_phys,
> +intc.base + LOCAL_MAILBOX3_SET0 + 16 * cpu);

Please explain why you need this dsb() - I can't see a reason for it.
writel() has a barrier internally prior to writing the register, and
therefore I think the above dsb() is entirely redundant.

-- 
RMK's Patch system: http://www.arm.linux.org.uk/developer/patches/
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.
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