linux-kernel - Re: [PATCH] rtc-cmos: fix broken NVRAM bank 2 writing

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Message-Id: <201111230829.20010.linux@rainbow-software.org>
Date:	Wed, 23 Nov 2011 08:29:19 +0100
From:	Ondrej Zary <linux@...nbow-software.org>
To:	Andrew Morton <akpm@...ux-foundation.org>
Cc:	Alessandro Zummo <a.zummo@...ertech.it>,
	rtc-linux@...glegroups.com,
	Kernel development list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] rtc-cmos: fix broken NVRAM bank 2 writing

On Wednesday 23 November 2011, Andrew Morton wrote:
> On Sun, 13 Nov 2011 23:20:31 +0100
>
> Ondrej Zary <linux@...nbow-software.org> wrote:
> > Fix writing to NVRAM bank 2 in rtc-cmos driver. It never worked since its
> > introduction in 2.6.28 because of a typo.
> >
> > Signed-off-by: Ondrej Zary <linux@...nbow-software.org>
> >
> > --- linux-3.1-orig/drivers/rtc/rtc-cmos.c	2011-10-24 09:10:05.000000000
> > +0200 +++ linux-3.1/drivers/rtc/rtc-cmos.c	2011-11-08 17:43:29.000000000
> > +0100 @@ -164,7 +164,7 @@ static inline unsigned char cmos_read_ba
> >  static inline void cmos_write_bank2(unsigned char val, unsigned char
> > addr) {
> >  	outb(addr, RTC_PORT(2));
> > -	outb(val, RTC_PORT(2));
> > +	outb(val, RTC_PORT(3));
> >  }
> >
> >  #else
>
> Strange.  Can you suggest why this bug has lived for so long without anyone
> noticing it?

Probably because nobody uses it. It's hidden in sysfs 
(/sys/class/rtc/rtc0/device/nvram) and there's another (old) module "nvram" 
that does (mostly) the same thing (except there's no bank 2 support). 

-- 
Ondrej Zary
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