From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH] [RFC] Potential bug in defining 'irq field' of 'ifmap
 structure'
Date: Mon, 06 Jul 2009 17:25:01 -0700 (PDT)
Message-ID: <20090706.172501.136390568.davem@davemloft.net>
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From: "Sonasath, Moiz" <m-sonasath@ti.com>
Date: Mon, 6 Jul 2009 17:23:36 -0500

> There seems to be a bug in the ioctl implementation in /kernel/net/core/dev.c 
>  
> dev_ifsioc_locked()
> 	case SIOCGIFMAP:
> 			ifr->ifr_map.irq = dev->irq;   // ?? type mismatch
> 
> Here
> ifr->ifr_map.irq) is of type unsigned char
> dev-irq is of type unsigned int
> 
> So ifconfig reports a wrong irq number when the dev->irq number is > 255.

This is a known and unavoidable limitation of this interface.
It's only real use is to control ISA style IRQs which are
< 255.

> I am confused to see the same typedefs in file: net/if.h 
> Not sure how to make changes for the user side net/if.h file?
> 
> Signed-off-by: Moiz Sonasath <m-sonasath@ti.com>
> Signed-off-by: Vikram Pandita <vikram.pandita@ti.com>

You can't make these kinds of changes, every userland binary out there
using this structure would break.