[PATCH 4/7] video stm/mx2x: allow to pass in fb memory from platform data

[Juergen Beisert]

Sascha Hauer wrote:
> Signed-off-by: Sascha Hauer <s.hauer at pengutronix.de>
> ---
>  arch/arm/mach-stm/include/mach/fb.h |    3 +++
>  drivers/video/stm.c                 |   11 +++++++++--
>  2 files changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm/mach-stm/include/mach/fb.h
> b/arch/arm/mach-stm/include/mach/fb.h index 65e3be2..2eade76 100644
> --- a/arch/arm/mach-stm/include/mach/fb.h
> +++ b/arch/arm/mach-stm/include/mach/fb.h
> @@ -37,6 +37,9 @@ struct imx_fb_videomode {
>
>  	unsigned dotclk_delay;	/**< refer manual HW_LCDIF_VDCTRL4 register */
>  	unsigned ld_intf_width;	/**< refer STMLCDIF_* macros */
> +
> +	void *fixed_screen;	/**< if != NULL use this as framebuffer memory */
> +	unsigned fixed_screen_size; /**< framebuffer memory size for fixed_screen
> */ };
>
>  #endif /* __MACH_FB_H */
> diff --git a/drivers/video/stm.c b/drivers/video/stm.c
> index d2add41..fc90b6a 100644
> --- a/drivers/video/stm.c
> +++ b/drivers/video/stm.c
> @@ -298,8 +298,15 @@ static int stmfb_activate_var(struct fb_info *fb_info)
>  	size = calc_line_length(mode->xres, fb_info->bits_per_pixel) *
>  		mode->yres;
>
> -	fb_info->screen_base = xrealloc(fb_info->screen_base, size);
> -	fbi->memory_size = size;
> +	if (pdata->fixed_screen) {
> +		if (pdata->fixed_screen_size < size)
> +			return -ENOMEM;
> +		fb_info->screen_base = pdata->fixed_screen;
> +		fbi->memory_size = pdata->fixed_screen_size;
> +	} else {
> +		fb_info->screen_base = xrealloc(fb_info->screen_base, size);
> +		fbi->memory_size = size;
> +	}
>
>  	/** @todo ensure HCLK is active at this point of time! */

Here for the case a user selects a screen resolution and colour depth that 
needs more memory than available, the routine returns with an error message 
for the fixed sized screen and with a reboot for the dynamic allocation case.

jbe

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