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Date: Mon, 22 Dec 2014 10:49:40 -0800
From: Andi Kleen <ak@linux.intel.com>
To: Alex Deucher <alexdeucher@gmail.com>
Cc: Oded Gabbay <oded.gabbay@amd.com>, Dana Elifaz <Dana.Elifaz@amd.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Maling list - DRI developers 
	<dri-devel@lists.freedesktop.org>,
        Alexander Deucher <Alexander.Deucher@amd.com>, LKP ML <lkp@01.org>,
        rusty@rustcorp.co.au
Subject: Re: [LKP] [PATCH] drm/radeon: Try to init amdkfd only if 64 bit
 kernel
Message-ID: <20141222184940.GB17192@tassilo.jf.intel.com>
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On Mon, Dec 22, 2014 at 11:58:43AM -0500, Alex Deucher wrote:
> On Mon, Dec 22, 2014 at 6:11 AM, Oded Gabbay <oded.gabbay@amd.com> wrote:
> > amdkfd driver can be compiled only in 64-bit kernel. Therefore, there is no
> > point in trying to initialize amdkfd in 32-bit kernel.
> >
> > In addition, in case of specific configuration of 32-bit kernel, no modules and
> > random kernel base, the symbol_request function doesn't work as expected - It
> > doesn't return NULL if the symbol doesn't exists. That makes the kernel panic.
> > Therefore, the as amdkfd doesn't compile in 32-bit kernel, the best way is just
> > to return false immediately.
> >
> > Signed-off-by: Oded Gabbay <oded.gabbay@amd.com>
> 
> Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

Sorry but the patch is just bogus. X-bit only code is usually
a very bad sign for the code. This is not windows programing after all.

Even if you wanted to do a 64bit only driver -- which
you probably don't -- the standard way would be to exclude
it in Kconfig.

Please root-cause why symbol_request doesn't work on 32bit
and fix it properly.

+rusty.

-Andi