3.16.61-rc1 review patch. If anyone has any objections, please let me know.
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From: Paul Bolle pebolle@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 pebolle@tiscali.nl Signed-off-by: Darren Hart dvhart@linux.intel.com Signed-off-by: Ben Hutchings ben@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)