At probe time, a clock device may not be ready when some other device wants to use it.

This patch lets the functions clk_get/devm_clk_get return a probe defer when the clock is defined in the DT but not yet available.

It also fixes an erroneous call to clk_get_sys() when __clk_get() fails.

Signed-off-by: Jean-Francois Moine moinejf@free.fr --- resend: - patch subject change from [PATCH v3 1/2] ASoC: kirkwood: clk: probe defer when clock not yet ready - base kernel 3.13.0-rc1 v2: fix __clk_get() failure (from Russell King) --- drivers/clk/clk.c | 2 +- drivers/clk/clkdev.c | 7 ++++++- 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 2cf2ea6..41361c6 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -2187,7 +2187,7 @@ EXPORT_SYMBOL_GPL(of_clk_del_provider); struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec) { struct of_clk_provider *provider; - struct clk *clk = ERR_PTR(-ENOENT); + struct clk *clk = ERR_PTR(-EPROBE_DEFER);

/* Check if we have such a provider in our array */ mutex_lock(&of_clk_lock); diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c index 442a313..1f402b9 100644 --- a/drivers/clk/clkdev.c +++ b/drivers/clk/clkdev.c @@ -157,7 +157,12 @@ struct clk *clk_get(struct device *dev, const char *con_id)

if (dev) { clk = of_clk_get_by_name(dev->of_node, con_id); - if (!IS_ERR(clk) && __clk_get(clk)) + if (!IS_ERR(clk)) { + if (!__clk_get(clk)) + clk = ERR_PTR(-ENOENT); + return clk; + } + if (PTR_ERR(clk) == -EPROBE_DEFER) return clk; }