Re: [RFC PATCH 3/5] of: add clock providers

From: Paul Mundt
Date: Wed Jan 26 2011 - 00:47:47 EST


On Tue, Jan 25, 2011 at 09:44:17PM -0700, Grant Likely wrote:
> +struct clk *of_clk_get(struct device *dev, const char *id)
> +{
...
> + snprintf(prop_name, 32, "%s-clock", id ? id : "bus");
> + prop = of_get_property(dev->of_node, prop_name, &sz);
> + if (!prop || sz < 4)
> + return NULL;
...
> + * size of the property. */
> + if (strlen(prop) + 1 > sz)
> + return NULL;
> +
> + /* Find the clock provider node; check if it is registered as a
> + * provider, and ask it for the relevant clk structure */
> + provnode = of_find_node_by_phandle(provhandle);
> + if (!provnode) {
> + pr_warn("%s: %s property in node %s references invalid phandle",
> + __func__, prop_name, dev->of_node->full_name);
> + return NULL;
...

> + return clk;
> +}

On Tue, Jan 25, 2011 at 09:44:22PM -0700, Grant Likely wrote:
> @@ -79,6 +81,11 @@ EXPORT_SYMBOL(clk_get_sys);
> struct clk *clk_get(struct device *dev, const char *con_id)
> {
> const char *dev_id = dev ? dev_name(dev) : NULL;
> + struct clk *clk;
> +
> + clk = of_clk_get(dev, con_id);
> + if (clk && __clk_get(clk))
> + return clk;
>
> return clk_get_sys(dev_id, con_id);
> }
>

The return value for clk_get() by almost all users is checked for
specifically with IS_ERR() rather than an IS_ERR_OR_NULL(), so you're
going to want to change your of_clk_get() error paths to return
ERR_PTR()'s directly, or wrap it up like clk_get_sys() does.

Given that there are multiple reasons why of_clk_get() can fail however,
it's probably worth handing down the actual error rather than simply
chomping it in to an -ENOENT.
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