Subject: [PATCH 3/3] clk: keystone: Add sci-clk driver support

From: [email-masked] (Stephen Boyd)
Date: Thu, 8 Dec 2016 13:10:44 -0800

On 12/08, Tero Kristo wrote:
> On 08/12/16 02:13, Stephen Boyd wrote:
> >On 10/21, Tero Kristo wrote:
> >>diff --git a/drivers/clk/keystone/sci-clk.c b/drivers/clk/keystone/sci-clk.c
> >>new file mode 100644
> >>index 0000000..f6af5bd
> >>--- /dev/null
> >>+++ b/drivers/clk/keystone/sci-clk.c
> 
> >
> >>+
> >>+	handle = devm_ti_sci_get_handle(dev);
> >>+	if (IS_ERR(handle))
> >>+		return PTR_ERR(handle);
> >>+
> >>+	provider = devm_kzalloc(dev, sizeof(*provider), GFP_KERNEL);
> >>+	if (!provider)
> >>+		return -ENOMEM;
> >>+
> >>+	provider->clocks = data;
> >>+
> >>+	provider->sci = handle;
> >>+	provider->ops = &handle->ops.clk_ops;
> >>+	provider->dev = dev;
> >>+
> >>+	ti_sci_init_clocks(provider);
> >
> >And if this fails?
> 
> Yea this is kind of controversial. ti_sci_init_clocks() can fail if
> any of the clocks registered will fail. I decided to have it this
> way so that at least some clocks might work in failure cause, and
> you might have a booting device instead of total lock-up.
> 
> Obviously it could be done so that if any clock fails, we would
> de-register all clocks at that point, but personally I think this is
> a worse option.
> 
> ti_sci_init_clocks could probably be modified to continue
> registering clocks when a single clock fails though. Currently it
> aborts at first failure.
> 

That sounds like a better approach if we don't care about
failures to register a clock. Returning a value from a function
and not using it isn't really a great design.

I worry that if we start returning errors from clk_hw_register()
that something will go wrong though, so really I don't know why
we want to ignore errors at all. Just for debugging a boot hang?
Can't we use early console to at least see that this driver is
failing to probe and debug that way?

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