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

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Message-ID: <20150625230437.GA4362@sci.fi>
Date:	Fri, 26 Jun 2015 02:04:37 +0300
From:	Ville Syrjälä <syrjala@....fi>
To:	"Luis R. Rodriguez" <mcgrof@...not-panic.com>
Cc:	akpm@...ux-foundation.org, bp@...e.de, mingo@...e.hu,
	ville.syrjala@...ux.intel.com, luto@...capital.net,
	tomi.valkeinen@...com, mst@...hat.com, benh@...nel.crashing.org,
	linux-kernel@...r.kernel.org, linux-fbdev@...r.kernel.org,
	linux-pci@...r.kernel.org, airlied@...hat.com,
	"Luis R. Rodriguez" <mcgrof@...e.com>,
	Toshi Kani <toshi.kani@...com>,
	Suresh Siddha <sbsiddha@...il.com>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Juergen Gross <jgross@...e.com>,
	Daniel Vetter <daniel.vetter@...ll.ch>,
	Antonino Daplas <adaplas@...il.com>,
	Jean-Christophe Plagniol-Villard <plagnioj@...osoft.com>,
	Rob Clark <robdclark@...il.com>,
	Mathias Krause <minipli@...glemail.com>,
	Andrzej Hajda <a.hajda@...sung.com>,
	Mel Gorman <mgorman@...e.de>, Vlastimil Babka <vbabka@...e.cz>,
	Davidlohr Bueso <dbueso@...e.de>
Subject: Re: [PATCH v5 1/3] video: fbdev: atyfb: clarify ioremap() base and
 length used

On Wed, Jun 24, 2015 at 06:34:18PM -0700, Luis R. Rodriguez wrote:
> From: "Luis R. Rodriguez" <mcgrof@...e.com>
> 
> This has no functional changes, it just adjusts
> the ioremap() call for the framebuffer to use
> the same values we later use for the framebuffer,
> this will make it easier to review the next change.
> 
> The size of the framebuffer varies but since this is
> for PCI we *know* this defaults to 0x800000.
> atyfb_setup_generic() is *only* used on PCI probe.
> 
> Cc: Toshi Kani <toshi.kani@...com>
> Cc: Suresh Siddha <sbsiddha@...il.com>
> Cc: Ingo Molnar <mingo@...e.hu>
> Cc: Linus Torvalds <torvalds@...ux-foundation.org>
> Cc: Thomas Gleixner <tglx@...utronix.de>
> Cc: Juergen Gross <jgross@...e.com>
> Cc: Daniel Vetter <daniel.vetter@...ll.ch>
> Cc: Andy Lutomirski <luto@...capital.net>
> Cc: Dave Airlie <airlied@...hat.com>
> Cc: Antonino Daplas <adaplas@...il.com>
> Cc: Jean-Christophe Plagniol-Villard <plagnioj@...osoft.com>
> Cc: Tomi Valkeinen <tomi.valkeinen@...com>
> Cc: Ville Syrjälä <syrjala@....fi>
> Cc: Rob Clark <robdclark@...il.com>
> Cc: Mathias Krause <minipli@...glemail.com>
> Cc: Andrzej Hajda <a.hajda@...sung.com>
> Cc: Mel Gorman <mgorman@...e.de>
> Cc: Vlastimil Babka <vbabka@...e.cz>
> Cc: Borislav Petkov <bp@...e.de>
> Cc: Davidlohr Bueso <dbueso@...e.de>
> Cc: linux-fbdev@...r.kernel.org
> Cc: linux-kernel@...r.kernel.org
> Signed-off-by: Luis R. Rodriguez <mcgrof@...e.com>
> ---
>  drivers/video/fbdev/aty/atyfb_base.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/video/fbdev/aty/atyfb_base.c b/drivers/video/fbdev/aty/atyfb_base.c
> index 16936bb..8025624 100644
> --- a/drivers/video/fbdev/aty/atyfb_base.c
> +++ b/drivers/video/fbdev/aty/atyfb_base.c
> @@ -3489,7 +3489,9 @@ static int atyfb_setup_generic(struct pci_dev *pdev, struct fb_info *info,
>  
>  	/* Map in frame buffer */
>  	info->fix.smem_start = addr;
> -	info->screen_base = ioremap(addr, 0x800000);
> +	info->fix.smem_len = 0x800000;
> +
> +	info->screen_base = ioremap(info->fix.smem_start, info->fix.smem_len);

The framebuffer size isn't always 8MB. That's the size of the BAR. So
this change isn't really correct. I suppose it doesn't hurt too much
since smem_len gets overwritten later in aty_init().

>  	if (info->screen_base == NULL) {
>  		ret = -ENOMEM;
>  		goto atyfb_setup_generic_fail;
> -- 
> 2.3.2.209.gd67f9d5.dirty
> 

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