3.16.61-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Paul Bolle <pebo...@tiscali.nl>
commit 95369a73a957ad221f1d6b8f11a63a376f38c544 upstream.
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: Paul Bolle <pebo...@tiscali.nl>
Signed-off-by: Darren Hart <dvh...@linux.intel.com>
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
drivers/platform/x86/eeepc-laptop.c | 36 ++++++++++++++---------------
1 file changed, 18 insertions(+), 18 deletions(-)
--- a/drivers/platform/x86/eeepc-laptop.c
+++ b/drivers/platform/x86/eeepc-laptop.c
@@ -263,13 +263,11 @@ static int acpi_setter_handle(struct eee
/*
* 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 dev
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)
+ rv = parse_arg(buf, &value);
+ if (rv < 0)
+ return rv;
+ rv = set_acpi(eeepc, cm, value);
+ if (rv < 0)
return -EIO;
- return rv;
+ 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
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(stru
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(stru
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 (*se
{
int rv, value;
- rv = parse_arg(buf, count, &value);
- if (rv > 0)
- set(value);
- return rv;
+ 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)
