From mboxrd@z Thu Jan  1 00:00:00 1970
From: linux@arm.linux.org.uk (Russell King - ARM Linux)
Date: Wed, 26 May 2010 21:10:17 +0100
Subject: [PATCH] ARM:VFPv3:enable {d16-d31} access
In-Reply-To: <5A47E75E594F054BAF48C5E4FC4B92AB0322FA8E37@dbde02.ent.ti.com>
References: <tarun.kanti@ti.com>
	<1274818736-26597-1-git-send-email-tarun.kanti@ti.com>
	<5A47E75E594F054BAF48C5E4FC4B92AB0322FA884E@dbde02.ent.ti.com>
	<20100525185741.GB16204@n2100.arm.linux.org.uk>
	<5A47E75E594F054BAF48C5E4FC4B92AB0322FA8E37@dbde02.ent.ti.com>
Message-ID: <20100526201017.GE6232@n2100.arm.linux.org.uk>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Wed, May 26, 2010 at 05:13:24PM +0530, DebBarma, Tarun Kanti wrote:
> 1) With the existing implementation I am not able to correctly
> write/read {d0-d15} but not the {d16-d31} set
> 
> 2) With my changes I am able to write/read correctly.

The reason this happens is simple.  In vfp_get_double(), we have:

1:      fmrrd   r0, r1, d\dr
1:      mrrc    p11, 3, r0, r1, c\dr    @ fmrrd r0, r1, d\dr

but in vfp_put_double(), we have:

1:      fmdrr   d\dr, r0, r1
1:      mcrr    p11, 3, r1, r2, c\dr    @ fmdrr r1, r2, d\dr

Note the different registers.  Change "r1, r2" to "r0, r1" and it
should work.