[LINUX PATCHv5] clk: clk-fixed-factor: Return EPROBE_DEFER to wait for dependent drivers

[LINUX PATCHv5] clk: clk-fixed-factor: Return EPROBE_DEFER to wait for dependent drivers

[Shubhrajyoti Datta]

In case the provider clock is not yet probed the fixed factor does not
find the name of the parent clock. This is because the parent clock is
not yet probed and in case of zynqmp the output-names is omitted.

This is a temporary solution however the critical components
like firmware probe should happen early.
Fixes a probe failure.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
---
v2:Fix the return value in other cases

 drivers/clk/clk-fixed-factor.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-factor.c
index f3ae4ff..36cbb0c 100644
--- a/drivers/clk/clk-fixed-factor.c
+++ b/drivers/clk/clk-fixed-factor.c
@@ -171,6 +171,8 @@ static struct clk *_of_fixed_factor_clk_setup(struct device_node *node)

        of_property_read_string(node, "clock-output-names", &clk_name);
        parent_name = of_clk_get_parent_name(node, 0);
+       if (!parent_name)
+               return ERR_PTR(-EPROBE_DEFER);

        if (of_match_node(set_rate_parent_matches, node))
                flags |= CLK_SET_RATE_PARENT;
--
2.1.1

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Re: [LINUX PATCHv5] clk: clk-fixed-factor: Return EPROBE_DEFER to wait for dependent drivers

[Stephen Boyd]

Quoting Shubhrajyoti Datta (2019-03-30 05:02:18)
> In case the provider clock is not yet probed the fixed factor does not
> find the name of the parent clock. This is because the parent clock is
> not yet probed and in case of zynqmp the output-names is omitted.
> 
> This is a temporary solution however the critical components
> like firmware probe should happen early.
> Fixes a probe failure.
> 
> Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
> ---

I'd prefer we move this to use the clk parent rewrite series I sent the
other day. That way the parents can be fetched when the clk is
registered or found later when the parent is registered. Can you try out
that series?

	https://lkml.kernel.org/r/20190404215344.6330-1-sboyd@kernel.org