Re: [PATCH 2/9] drivers/acpi/asus_acpi.c: Correct use of ! and &

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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? or can one always say that
!NON_ZERO_VALUE == 0 and !0 == 1?

Cheers, Mark.
--
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

[Index of Archives]     [Kernel Development]     [Kernel Announce]     [Kernel Newbies]     [Linux Networking Development]     [Share Photos]     [IDE]     [Security]     [Git]     [Netfilter]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Device Mapper]

  Powered by Linux