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Commit 95369a73 authored by Paul Bolle's avatar Paul Bolle Committed by Darren Hart
Browse files

eeepc-laptop: simplify parse_arg() 



parse_arg() has three possible return values:
    -EINVAL if sscanf(), in short, fails;
    zero if "count" is zero; and
    "count" in all other cases

But "count" will never be zero. See, parse_arg() is called by the
various store functions. And the callchain of these functions starts
with sysfs_kf_write(). And that function checks for a zero "count". So
we can stop checking for a zero "count", drop the "count" argument
entirely, and transform parse_arg() into a function that returns zero on
success or a negative error. That, in turn, allows to make those store
functions just return "count" on success. The net effect is that the
code becomes a bit easier to understand.

A nice side effect is that this GCC warning is silenced too:
    drivers/platform/x86/eeepc-laptop.c: In function ‘store_sys_acpi’:
    drivers/platform/x86/eeepc-laptop.c:279:10: warning: ‘value’ may be used uninitialized in this function [-Wmaybe-uninitialized]
      int rv, value;

Which is, of course, the reason to have a look at parse_arg().

Signed-off-by: default avatarPaul Bolle <pebolle@tiscali.nl>
Signed-off-by: default avatarDarren Hart <dvhart@linux.intel.com>
parent a3d3c53f

drivers/platform/x86/eeepc-laptop.c

+18 −18
Original line number Diff line number Diff line
@@ -263,13 +263,11 @@ static int acpi_setter_handle(struct eeepc_laptop *eeepc, int cm, 
/*

 * Sys helpers

 */

static int parse_arg(const char *buf, unsigned long count, int *val)

static int parse_arg(const char *buf, int *val)

{

	if (!count)

		return 0;

	if (sscanf(buf, "%i", val) != 1)

		return -EINVAL;

	return count;

	return 0;

}



static ssize_t store_sys_acpi(struct device *dev, int cm,
@@ -278,12 +276,13 @@ static ssize_t store_sys_acpi(struct device *dev, int cm, 
	struct eeepc_laptop *eeepc = dev_get_drvdata(dev);

	int rv, value;



	rv = parse_arg(buf, count, &value);

	if (rv > 0)

		value = set_acpi(eeepc, cm, value);

	if (value < 0)

		return -EIO;

	rv = parse_arg(buf, &value);

	if (rv < 0)

		return rv;

	rv = set_acpi(eeepc, cm, value);

	if (rv < 0)

		return -EIO;

	return count;

}



static ssize_t show_sys_acpi(struct device *dev, int cm, char *buf)
@@ -377,13 +376,13 @@ static ssize_t store_cpufv(struct device *dev, 
		return -EPERM;

	if (get_cpufv(eeepc, &c))

		return -ENODEV;

	rv = parse_arg(buf, count, &value);

	rv = parse_arg(buf, &value);

	if (rv < 0)

		return rv;

	if (!rv || value < 0 || value >= c.num)

	if (value < 0 || value >= c.num)

		return -EINVAL;

	set_acpi(eeepc, CM_ASL_CPUFV, value);

	return rv;

	return count;

}



static ssize_t show_cpufv_disabled(struct device *dev,
@@ -402,7 +401,7 @@ static ssize_t store_cpufv_disabled(struct device *dev, 
	struct eeepc_laptop *eeepc = dev_get_drvdata(dev);

	int rv, value;



	rv = parse_arg(buf, count, &value);

	rv = parse_arg(buf, &value);

	if (rv < 0)

		return rv;
@@ -412,7 +411,7 @@ static ssize_t store_cpufv_disabled(struct device *dev, 
			pr_warn("cpufv enabled (not officially supported "

				"on this model)\n");

		eeepc->cpufv_disabled = false;

		return rv;

		return count;

	case 1:

		return -EPERM;

	default:
@@ -1042,10 +1041,11 @@ static ssize_t store_sys_hwmon(void (*set)(int), const char *buf, size_t count) 
{

	int rv, value;



	rv = parse_arg(buf, count, &value);

	if (rv > 0)

		set(value);

	rv = parse_arg(buf, &value);

	if (rv < 0)

		return rv;

	set(value);

	return count;

}



static ssize_t show_sys_hwmon(int (*get)(void), char *buf)