Re: [RFC 2.6.27 1/2] fbdev: add E-Ink Broadsheet controller support

[linux@arm.linux.org.uk]

On Sun, Dec 21, 2008 at 06:59:34PM +0800, Jaya Kumar wrote:
> +static void broadsheetfb_dpy_update_pages(struct broadsheetfb_par *par,
> +						u16 y1, u16 y2)
> +{
> +	u16 args[5];
> +	unsigned char *buf = (unsigned char __force *)par->info->screen_base;

You shouldn't add __force inside drivers.

> +	videomemorysize = (DPY_W*DPY_H);
> +	videomemory = vmalloc(videomemorysize);
> +	if (!videomemory)
> +		goto err_fb_rel;
> +
> +	memset(videomemory, 0, videomemorysize);
> +
> +	info->screen_base = (char __force __iomem *)videomemory;

Ditto.

Also, using vmalloc for the backing store means this memory can't be
mmap()'d into userspace, which is a very common thing for framebuffer
using programs to do.  If mmap() is to be denied, then you should
provide a mmap implementation in the fb_ops structure.

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