On Wed, Sep 17, 2014 at 09:02:51PM +0200, Paul Bolle wrote: > 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@xxxxxxxxxx> > --- > Still build tested only, but now on top of v3.17-rc5. Has Frans tested > writing zero length values to these sysfs files? > > v3: store_sys_acpi() again returns -EIO if set_acpi() fails. > > v2: let store_sys_acpi() return whatever error set_acpi() returns > instead of remapping it to EIO. The new line about that in the commit > explanation is silly, but I couldn't come up with a better explanation. Queued, thanks. -- Darren Hart Intel Open Source Technology Center -- To unsubscribe from this list: send the line "unsubscribe platform-driver-x86" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
