From mboxrd@z Thu Jan  1 00:00:00 1970
From: Wu Zhangjin <wuzhangjin@gmail.com>
Subject: Re: [PATCH v8 5/8] Loongson: YeeLoong: add hardware monitoring
 driver
Date: Mon, 07 Dec 2009 17:41:10 +0800
Message-ID: <1260178870.9092.34.camel@falcon.domain.org>
References: <cover.1260082252.git.wuzhangjin@gmail.com>
	 <d8789fa7e97d8a170c4e2516d7ef2d2fbbe42cc6.1260082252.git.wuzhangjin@gmail.com>
	 <20091206084717.GD2766@ucw.cz> <1260147298.3126.2.camel@falcon.domain.org>
	 <20091207080446.GB23088@elf.ucw.cz>
Reply-To: wuzhangjin@gmail.com
Mime-Version: 1.0
Content-Transfer-Encoding: 7bit
Return-path: <linux-laptop-owner@vger.kernel.org>
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=gmail.com; s=gamma;
        h=domainkey-signature:received:received:subject:from:reply-to:to:cc
         :in-reply-to:references:content-type:organization:date:message-id
         :mime-version:x-mailer:content-transfer-encoding;
        bh=iueJ1ZW90iKbeFUGWAPugb/6njng6PWnLl9laIu155A=;
        b=wq44n3qQQ0JoGWw8fDiKXwriH9TLrrqLRqo5MfbpKW0238mC2cZgn23QKQVdS23SIN
         8rOsOgnfyMB+p9DzJWoanZlLrGBGS5FjWWo56TE2rmaL78DaK/9ZgNUvsoeqFIyODE62
         UI5zWim8MkzCx9633mMO3Cw1FpT87AaTJW30c=
In-Reply-To: <20091207080446.GB23088@elf.ucw.cz>
Sender: linux-laptop-owner@vger.kernel.org
List-ID: <linux-laptop.vger.kernel.org>
Content-Type: text/plain; charset="us-ascii"
To: Pavel Machek <pavel@ucw.cz>
Cc: Ralf Baechle <ralf@linux-mips.org>, akpm@linux-foundation.org, linux-mips@linux-mips.org, linux-kernel@vger.kernel.org, Dmitry Torokhov <dmitry.torokhov@gmail.com>, "Rafael J . Wysocki" <rjw@sisk.pl>, zhangfx@lemote.com, linux-laptop@vger.kernel.org, Stephen Rothwell <sfr@canb.auug.org.au>

On Mon, 2009-12-07 at 09:04 +0100, Pavel Machek wrote:
> > > What is going on here? I thought the value is already in two's
> > > complement... Is the above equivalent of
> > > 
> > > 	      if (value < 0)
> > > 	      	 value = -value; 
> > > 
> > > ? If so, why? If not, can you add a comment?
> > 
> > Right, then, will use this instead:
> > 
> > static int get_battery_current(void)
> > { 
> > 	s16 value;
> > 
> > 	value = (ec_read(REG_BAT_CURRENT_HIGH) << 8) |
> > 		(ec_read(REG_BAT_CURRENT_LOW));
> > 
> > 	return abs(value);
> > }
> 
> That's certainly better. But... why not return signed value? Current
> flowing from the battery is certainly very different from current
> flowing into it...

You are totally right ;)

Just test it, when flowing from the battery, the value is negative, and
when flowing into the battery, the value is positive, so, no abs()
needed. thanks!

BTW: This part of source code was written by another EC guy, not checked
it carefully, sorry ;)

Best Regards,
	Wu Zhangjin