Subject: Re: [PATCH] powerpc/fsl-booke: Work around erratum A-006958

From: Scott Wood <[email-masked]>
Date: Mon, 15 Jul 2013 17:15:58 -0500

On 07/15/2013 11:53:54 AM, Scott Wood wrote:
> On 07/15/2013 03:45:36 AM, David Laight wrote:
>> Also, if the high word changes, there is no need to loop.
>> Just return the second value with a low word of zero
>> (the returned count happened while the function was active).
>=20
> That would be more complicated than looping.

That said, it's since been confirmed internally that the low word =20
should always be zero when this happens, so we could share the Cell =20
workaround code -- as long as we do something special in the timebase =20
sync code so that we don't get stuck if the timebase happens to be =20
frozen with TBL=3D=3D0.  This would avoid the need for scratch registers =20
(other than CR0).

-Scott=