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    SubjectRe: [PATCH 14/26] clk: mvebu: Convert to clk_hw based provider APIs
    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;
    --
    Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
    a Linux Foundation Collaborative Project

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