From mboxrd@z Thu Jan  1 00:00:00 1970
From: Daniel Vetter <daniel@ffwll.ch>
Subject: Re: [PATCH 2/2] drm/i915: properly prefault for
	pread/pwrite
Date: Sun, 23 Oct 2011 12:18:30 +0200
Message-ID: <20111023101830.GE2953@phenom.ffwll.local>
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To: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>, intel-gfx <intel-gfx@lists.freedesktop.org>, stable@kernel.org
List-Id: intel-gfx@lists.freedesktop.org

Hi Keith,

This patch isn't in your -next pull. This papers over a spurious -EFAULT
in the pwrite/pread paths that actually gets hit in the wild. The real fix
in the form of a almost complete rewrite of the pwrite/pread paths won't
be ready for 3.2.

Do you want me to implement Chris' beautification suggestion? The code
as-is is copied over from the pagecache prefault helper. Otherwise please
consider merging for 3.2.

Yours, Daniel

On Wed, Sep 28, 2011 at 12:24:04PM +0100, Chris Wilson wrote:
> > +	if (ret == 0) {
> > +		if (((unsigned long)uaddr & PAGE_MASK) !=
> > +				((unsigned long)end & PAGE_MASK))
> This is a little ugly. Perhaps,
> 
>   #define page_align(addr) ((unsigned long)addr & PAGE_MASK)
>   if (page_align(uaddr) != page_align(end))
> 
> Otherwise, both are
> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
> -Chris
> 
> -- 
> Chris Wilson, Intel Open Source Technology Centre

-- 
Daniel Vetter
Mail: daniel@ffwll.ch
Mobile: +41 (0)79 365 57 48