From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH v3 1/4] net/macb: fix truncate warnings
Date: Tue, 23 Oct 2012 04:48:29 -0400 (EDT)
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From: "David Laight" <David.Laight@ACULAB.COM>
Date: Tue, 23 Oct 2012 09:21:11 +0100

>> When building macb on x86_64 the following warnings show up:
>>   drivers/net/ethernet/cadence/macb.c: In function macb_interrupt:
>>   drivers/net/ethernet/cadence/macb.c:556:4: warning: large integer implicitly truncated to unsigned type [-Woverflow]
> ...
>> -			macb_writel(bp, IDR, ~0UL);
>> +			macb_writel(bp, IDR, -1);
> 
> Seems wrong to fix an error with an unsigned value
> by using -1.

-1 is equally an unsigned value of all 1's and completely legitimate.
The correction being made here is one of size not signedness.