From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= <syrjala@sci.fi>
Date: Wed, 08 Jul 2015 08:38:49 +0000
Subject: Re: [PATCH v5 1/3] video: fbdev: atyfb: clarify ioremap() base and length used
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To: "Luis R. Rodriguez" <mcgrof@suse.com>
Cc: Borislav Petkov <bp@suse.de>, Andrew Morton <akpm@linux-foundation.org>, Ingo Molnar <mingo@elte.hu>, Ville =?iso-8859-1?Q?Syrj=E4l=E4?= <ville.syrjala@linux.intel.com>, Andy Lutomirski <luto@amacapital.net>, Tomi Valkeinen <tomi.valkeinen@ti.com>, "Michael S. Tsirkin" <mst@redhat.com>, Benjamin Herrenschmidt <benh@kernel.crashing.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, linux-fbdev <linux-fbdev@vger.kernel.org>, "linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>, Dave Airlie <airlied@redhat.com>, Toshi Kani <toshi.kani@hp.com>, Suresh Siddha <sbsiddha@gmail.com>, Linus Torvalds <torvalds@linux-foundation.org>, Thomas Gleixner <tglx@linutronix.de>, Juergen Gross <jgross@suse.com>, Daniel Vetter <daniel.vetter@ffwll.ch>, Antonino Daplas <adaplas@gmail.com>, Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>, Rob Clark <robdclark@gmail.com>, Mathias Krause <minipli@googlemail.com>, Andrzej Hajda <a.hajda@samsung.com>, Mel Gorman <mgorman@suse.de>, Vlastimil Babka <vbabka@suse.cz>, Davidlohr Bueso <dbueso@suse.de>

On Tue, Jul 07, 2015 at 05:24:57PM -0700, Luis R. Rodriguez wrote:
> On Thu, Jul 2, 2015 at 4:23 PM, Luis R. Rodriguez <mcgrof@suse.com> wrote:
> > On Fri, Jun 26, 2015 at 12:30 AM, Borislav Petkov <bp@suse.de> wrote:
> >> On Fri, Jun 26, 2015 at 03:09:27AM +0200, Luis R. Rodriguez wrote:
> >>> Sure, mind this as a follow up patch if its too late?
> >>
> >> No need, you can send me an updated one - I'll replace it.
> >
> > Will do!
>=20
> OK the commend I'm adding:
>=20
> @@ -3489,6 +3489,15 @@ static int atyfb_setup_generic(struct pci_dev
> *pdev, struct fb_info *info,
>=20
>         /* Map in frame buffer */
>         info->fix.smem_start =3D addr;
> +
> +       /*
> +        * The framebuffer is not always 8 MiB that's just the size of the
> +        * PCI BAR, this is later corrected for use with write-combining
> +        * helpers with aty_fudge_framebuffer_len() which will adjust the
> +        * framebuffer accordingly depending on the device.

That somehow gives me the impression that aty_fudge_framebuffer_len()
changes smem_len to match the framebuffer size, which it does
not.

Dunno, maybe something like this?
/*
 * The framebuffer is not always 8 MiB that's just the size of the
 * PCI BAR. We temporarily abuse smem_len here to store the size
 * of the BAR. aty_init() will later correct it to match the actual
 * framebuffer size.
 *
 * On devices that don't have the auxiliary register aperture, the
 * registers are housed at the top end of the framebuffer PCI BAR.
 * aty_fudge_framebuffer_len() is used to reduce smem_len to not
 * overlap with the registers.
 */

> We do this
> +        * to match semantics over ioremap calls on framebuffer devices
> +        * with with other drivers with the info->fix.smem_len.
> +        */
>         info->fix.smem_len =3D 0x800000;
>=20
>         info->screen_base =3D ioremap(info->fix.smem_start, info->fix.sme=
m_len);
>=20
> Will respin.
>=20
>  Luis

--=20
Ville Syrj=E4l=E4
syrjala@sci.fi
http://www.sci.fi/~syrjala/