Re: [PATCH 3/3] fbdev: sh_mobile_lcdc: use dma_mmap_coherent if available

From: Laurent Pinchart
Date: Wed Jul 25 2012 - 07:10:36 EST


Hi Eiraku-san,

Thank you for the patch.

On Wednesday 25 July 2012 15:29:24 Hideki EIRAKU wrote:
> fb_mmap() implemented in fbmem.c uses smem_start as the physical
> address of the frame buffer. In the sh_mobile_lcdc driver, the
> smem_start is a dma_addr_t that is not a physical address when IOMMU is
> enabled. dma_mmap_coherent() maps the address correctly. It is
> available on ARM platforms.

This looks good to me, but will need to be rebased on top of the
sh_mobile_lcdc patches currently queued for v3.6. You can find them in the
fbdev-next branch of git://github.com/schandinat/linux-2.6.git.

In particular, these patches add support for overlays exported through
additional fbdev devices. You will need to initialize .fb_mmap in both
sh_mobile_lcdc_overlay_ops and sh_mobile_lcdc_ops.

> Signed-off-by: Hideki EIRAKU <hdk@xxxxxxxxxx>
> ---
> drivers/video/sh_mobile_lcdcfb.c | 14 ++++++++++++++
> 1 files changed, 14 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/video/sh_mobile_lcdcfb.c
> b/drivers/video/sh_mobile_lcdcfb.c index e672698..65732c4 100644
> --- a/drivers/video/sh_mobile_lcdcfb.c
> +++ b/drivers/video/sh_mobile_lcdcfb.c
> @@ -1393,6 +1393,17 @@ static int sh_mobile_lcdc_blank(int blank, struct
> fb_info *info) return 0;
> }
>
> +#ifdef ARCH_HAS_DMA_MMAP_COHERENT
> +static int
> +sh_mobile_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
> +{
> + struct sh_mobile_lcdc_chan *ch = info->par;
> +
> + return dma_mmap_coherent(ch->lcdc->dev, vma, ch->fb_mem,
> + ch->dma_handle, ch->fb_size);
> +}
> +#endif
> +
> static struct fb_ops sh_mobile_lcdc_ops = {
> .owner = THIS_MODULE,
> .fb_setcolreg = sh_mobile_lcdc_setcolreg,
> @@ -1408,6 +1419,9 @@ static struct fb_ops sh_mobile_lcdc_ops = {
> .fb_release = sh_mobile_release,
> .fb_check_var = sh_mobile_check_var,
> .fb_set_par = sh_mobile_set_par,
> +#ifdef ARCH_HAS_DMA_MMAP_COHERENT
> + .fb_mmap = sh_mobile_fb_mmap,
> +#endif
> };
>
> static void
--
Regards,

Laurent Pinchart

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