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Date: Tue, 21 May 2013 18:10:31 +1000
From: Paul Mackerras <paulus@samba.org>
To: Chen Gang <gang.chen@asianux.com>
Subject: Re: [PATCH] PowerPC: kernel: need return the related error code when
 failure occurs.
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Cc: Arnd Bergmann <arnd@arndb.de>,
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On Tue, May 21, 2013 at 01:48:58PM +0800, Chen Gang wrote:
> 
> When error occurs, need return the related error code to let upper
> caller know about it.
> 
> ppc_md.nvram_size() can return the error code (e.g. core99_nvram_size()
> in 'arch/powerpc/platforms/powermac/nvram.c').
> 
> And when '*ppos >= size', need return -ESPIPE (Illegal seek)

Why?  When *ppos >= size, it should return 0 (end of file) in my opinion.
ESPIPE means that any seek would be ineffective, not that a particular
seek went out of bounds.

Paul.