Re: [PATCH] Proposed removal of IS_ERR_OR_NULL() (was: Re: [PATCH1/4] gpiolib: introduce descriptor-based GPIO interface)

From: Russell King - ARM Linux
Date: Wed Jan 09 2013 - 10:52:07 EST


On Wed, Jan 09, 2013 at 10:27:53AM -0500, Nicolas Pitre wrote:
> Anyone with good coccinelle skills around to deal with the users?

I'm not sure that's a solution.

For example:

err = gpio_request(en_vdd_1v05, "EN_VDD_1V05");
if (err) {
pr_err("%s: gpio_request failed: %d\n", __func__, err);
return err;
}
...
regulator = regulator_get(NULL, "vdd_ldo0,vddio_pex_clk");
if (IS_ERR_OR_NULL(regulator)) {
pr_err("%s: regulator_get failed: %d\n", __func__,
(int)PTR_ERR(regulator));
goto err_reg;
}

regulator_enable(regulator);

err = tegra_pcie_init(true, true);
...
err_reg:
gpio_free(en_vdd_1v05);

return err;
}

Now, regulator_get() returns error-pointers for real errors when it's
configured in. When regulator support is not configured, it returns
NULL.

So, one solution here would be:

if (IS_ERR(regulator)) {
err = PTR_ERR(regulator);
pr_err("%s: regulator_get failed: %d\n", __func__, err);
goto err_reg;
}

but leaves us with the question: is it safe to call tegra_pcie_init()
without regulator support?

The problem there is that "fixing" this causes a behavioural change in
the code, and we don't know what effect that change may have.
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