Re: [PATCH v5 1/3] video: fbdev: atyfb: clarify ioremap() base and length used

[Ville Syrjälä]

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@xxxxxxxx> wrote:
> > On Fri, Jun 26, 2015 at 12:30 AM, Borislav Petkov <bp@xxxxxxx> 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!
> 
> OK the commend I'm adding:
> 
> @@ -3489,6 +3489,15 @@ static int atyfb_setup_generic(struct pci_dev
> *pdev, struct fb_info *info,
> 
>         /* Map in frame buffer */
>         info->fix.smem_start = 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 = 0x800000;
> 
>         info->screen_base = ioremap(info->fix.smem_start, info->fix.smem_len);
> 
> Will respin.
> 
>  Luis

-- 
Ville Syrjälä
syrjala@xxxxxx
http://www.sci.fi/~syrjala/
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