On Wed, Sep 17, 2014 at 01:35:10PM -0700, Darren Hart wrote: > 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? > > Frans, can you confirm testing when you get a chance please? Tested. Looks OK to me. Frans -- 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
