From mboxrd@z Thu Jan  1 00:00:00 1970
From: gregory.clement@free-electrons.com (Gregory CLEMENT)
Date: Tue, 23 Oct 2012 11:11:53 +0200
Subject: [PATCH 5/5] arm: mvebu: Added SMP support for Armada XP
In-Reply-To: <20121022184537.GN21046@lunn.ch>
References: <1350925368-24243-1-git-send-email-gregory.clement@free-electrons.com>
 <1350925368-24243-6-git-send-email-gregory.clement@free-electrons.com>
 <20121022184537.GN21046@lunn.ch>
Message-ID: <50865F59.8000507@free-electrons.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On 10/22/2012 08:45 PM, Andrew Lunn wrote:
> Hi Gregory
> 
>> +void __init set_secondary_cpus_clock(void)
>> +{
>> +	int cpu;
>> +	unsigned long rate;
>> +	struct clk *cpu_clk = NULL;
>> +	struct device_node *np = NULL;
>> +
>> +	cpu = smp_processor_id();
>> +	np = of_find_node_by_type(np, "cpu");
>> +	np = NULL;
>> +	while ((np = of_find_node_by_type(np, "cpu"))) {
>> +		const u32 *reg;
>> +		int len;
>> +		reg = of_get_property(np, "reg", &len);
>> +		if (!reg || len != 4) {
>> +			pr_err("%s missing reg property\n", np->full_name);
>> +			continue;
>> +		}
>> +		if (be32_to_cpup(reg) == cpu) {
>> +			cpu_clk = of_clk_get(np, 0);
>> +			break;
>> +		}
>> +	}
>> +	WARN_ON(IS_ERR(cpu_clk));
>> +	rate = clk_get_rate(cpu_clk);
>> +
>> +	/* set all the other CPU clk to the same rate than the boot CPU */
>> +	np = NULL;
>> +	while ((np = of_find_node_by_type(np, "cpu"))) {
>> +		const u32 *reg;
>> +		int len;
>> +		reg = of_get_property(np, "reg", &len);
>> +		if (!reg || len != 4) {
>> +			pr_err("%s missing reg property\n", np->full_name);
>> +			continue;
>> +		}
>> +		if (be32_to_cpup(reg) != cpu) {
>> +			cpu_clk = of_clk_get(np, 0);
>> +			clk_set_rate(cpu_clk, rate);
>> +		}
> 
> Maybe its hiding somewhere, but where is the clk_prepare_enable() for
> this cpu_clk clock?
> 

Well the clocks are always enable. In the clock framework, the cpu clocks
don't provide an enable function.
But maybe it is cleaner to call clk_prepare_enable() even if it does
nothing except update the usage count.

Thanks,

Gregory