From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dan Carpenter <error27@gmail.com>
Date: Thu, 28 Oct 2010 10:58:40 +0000
Subject: Re: bug report: signedness issue in ds3232_update_alarm()
Message-Id: <20101028105840.GB6062@bicker>
List-Id: <kernel-janitors.vger.kernel.org>
References: <20101028083503.GZ6062@bicker>
In-Reply-To: <20101028083503.GZ6062@bicker>
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To: kernel-janitors@vger.kernel.org

On Thu, Oct 28, 2010 at 06:15:46PM +0800, Lan Chunhe-B25806 wrote:
>       Of course, bcd2bin()/Time is never less than zero. But it is fault  
> tolerant.
>       When time has exceptional data, it set time to the default value.
>

Sorry, I still don't understand what you're trying to do.  This showed
up on my bug scanner, and I've studied it but as far as I can see it
doesn't do anything.  I've created a sample program to demonstrate what
I mean.

It passes every possible non-zero value to bcd2bin() and counts how many
of the returns are negative.

regards,
dan carpenter

#include <stdio.h>

unsigned bcd2bin(unsigned char val)
{
        return (val & 0x0f) + (val >> 4) * 10;
}

int main(int argc, char **argv)
{
	unsigned char x;
	int useful = 0;

	for (x = 1; x; x++) {
		if (bcd2bin(x) < 0)
			useful++;
	}

	printf("useful = %d\n", useful);
	return 0;
}