On 10/14, Thomas Petazzoni wrote:
> On Fri, 31 Jul 2015 10:03:54 -0700, Stephen Boyd wrote:
> > @@ -209,9 +208,8 @@ static void __init of_cpu_clk_setup(struct device_node
> > *node)
> > goto bail_out;
> >
> > sprintf(clk_name, "cpu%d", cpu);
> > - parent_clk = of_clk_get(node, 0);
> >
> > - cpuclk[cpu].parent_name = __clk_get_name(parent_clk);
> > + cpuclk[cpu].parent_name = of_clk_get_parent_name(node, 0);
> > cpuclk[cpu].clk_name = clk_name;
> > cpuclk[cpu].cpu = cpu;
> > cpuclk[cpu].reg_base = clock_complex_base;
>
> Sorry to chime in only right now, but this patch causes a regression on
> Armada XP: the cpu clocks are no longer seen as child of their parent
> and therefore their rate is always 0. This breaks cpufreq on this
> platform.
>
[...]
>
> Stephen, what do you suggest to fix this issue?
Simplest fix is to revert this hunk. Longer term, we should look
into making of_clk_get_parent_name() use whatever string has been
used when registering the clock, or completely change how we do
parent child linkages so that strings aren't necessary.
>
> The easiest solution is to add a clock-output-names property to the
> coreclk node. This way, of_clk_get_parent_name() will properly resolve
> the clock name to its correct name (i.e, "cpuclk" in our case) and
> everything works fine (I've tested). The drawback of this solution is
> that it breaks backward compatibility with old DTs: a 4.2 DT for Armada
> XP would no longer work with a >= 4.3 kernel.
>
> Do you have some other suggestions to make ?
>
How about this patch?
---8<----
diff --git a/drivers/clk/mvebu/clk-cpu.c b/drivers/clk/mvebu/clk-cpu.c
index 5837eb8a212f..85da8b983256 100644
--- a/drivers/clk/mvebu/clk-cpu.c
+++ b/drivers/clk/mvebu/clk-cpu.c
@@ -197,6 +197,7 @@ static void __init of_cpu_clk_setup(struct device_node
*node)
for_each_node_by_type(dn, "cpu") {
struct clk_init_data init;
struct clk *clk;
+ struct clk *parent_clk;
char *clk_name = kzalloc(5, GFP_KERNEL);
int cpu, err;
@@ -208,8 +209,9 @@ static void __init of_cpu_clk_setup(struct device_node
*node)
goto bail_out;
sprintf(clk_name, "cpu%d", cpu);
+ parent_clk = of_clk_get(node, 0);
- cpuclk[cpu].parent_name = of_clk_get_parent_name(node, 0);
+ cpuclk[cpu].parent_name = __clk_get_name(parent_clk);
cpuclk[cpu].clk_name = clk_name;
cpuclk[cpu].cpu = cpu;
cpuclk[cpu].reg_base = clock_complex_base;
--
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