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From: Arnd Bergmann <arnd@arndb.de>
To: linuxppc-dev@ozlabs.org
Subject: Re: [PATCH] powerpc: make ioport_map() handle already mapped ranges
Date: Sun, 13 May 2007 00:18:42 +0200
References: <20070512143221.GB12890@lixom.net>
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Cc: Olof Johansson <olof@lixom.net>, paulus@samba.org
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On Saturday 12 May 2007, Olof Johansson wrote:
> Make ioport_map() handle already mapped port range without trying
> to add _IO_BASE to them.
>=20
>=20
> Signed-off-by: Olof Johansson <olof@lixom.net>
>=20
> Index: 2.6.21/arch/powerpc/kernel/iomap.c
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> --- 2.6.21.orig/arch/powerpc/kernel/iomap.c
> +++ 2.6.21/arch/powerpc/kernel/iomap.c
> @@ -106,7 +106,13 @@ EXPORT_SYMBOL(iowrite32_rep);
> =A0
> =A0void __iomem *ioport_map(unsigned long port, unsigned int len)
> =A0{
> -=A0=A0=A0=A0=A0=A0=A0return (void __iomem *) (port + _IO_BASE);
> +=A0=A0=A0=A0=A0=A0=A0/* Do nothing if we're being asked to map an already
> +=A0=A0=A0=A0=A0=A0=A0 * ioremapped() address
> +=A0=A0=A0=A0=A0=A0=A0 */
> +=A0=A0=A0=A0=A0=A0=A0if (port >=3D IMALLOC_BASE && (port+len) < IMALLOC_=
END)
> +=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0return (void __iomem *) por=
t;
> +=A0=A0=A0=A0=A0=A0=A0else
> +=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0return (void __iomem *) (po=
rt + _IO_BASE);
> =A0}

This patch looks wrong to me, it's an indication that either a driver
is confusing ioport and __iomem addresses, or that something went
wrong during the initialization of the primary PCI bus.

We have a bug on cell that would be fixed with this patch, so it
might be the same problem, see the patch that I suggested for
this at http://patchwork.ozlabs.org/linuxppc/patch?id=3D10840 .

	Arnd <><