On Fri, 29 Feb 2008 19:06:48 +0100 Mark Pearson <devnull.port@xxxxxxxxxxxxxx> wrote: > Andrew Morton wrote: > >> Seems an odd way of doing: > >> > >> led_out ^= 0x01; > > > > It does. > > > >> It this due to some optimisation? > > > > Surely not ;) > > > ;) Thought so - one doesn't like to be too presumptuous ;) > > > That code has been there for many years. > > > > I changed the patch to this: > > > > --- a/drivers/acpi/asus_acpi.c~drivers-acpi-asus_acpic-correct-use-of-and > > +++ a/drivers/acpi/asus_acpi.c > > @@ -610,7 +610,7 @@ write_led(const char __user * buffer, un > > (led_out) ? (hotk->status | ledmask) : (hotk->status & ~ledmask); > > > > if (invert) /* invert target value */ > > - led_out = !led_out & 0x1; > > + led_out = !led_out; > > > > if (!write_acpi_int(hotk->handle, ledname, led_out, NULL)) > > printk(KERN_WARNING "Asus ACPI: LED (%s) write failed\n", > > _ > > > > > > Is the ! operator architecture/compiler dependent? It shouldn't be. > or can one always say that > !NON_ZERO_VALUE == 0 and !0 == 1? > I always have ;) I expect it's in the C standard somewhere. -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
