[PATCH 6/7] video: stm32: stm32_ltdc: align framebuffer on 2MB

[Patrice CHOTARD]

Hi Patrick

On 11/15/21 4:32 PM, Patrick Delaunay wrote:
> Align the framebuffer size on MMU_SECTION_SIZE in kernel, = max 2MB for
> LPAE for armV7, to avoid issue with the simple frame buffer activation,
> when U-Boot add a reserved memory in the kernel device tree to preserve
> the splash screen until Linux driver initialization.
> 
> See Linux documentation for details:
> Documentation/devicetree/bindings/display/simple-framebuffer.yaml
> 
> Signed-off-by: Patrick Delaunay <patrick.delaunay at foss.st.com>
> ---
> 
>  drivers/video/stm32/stm32_ltdc.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/video/stm32/stm32_ltdc.c b/drivers/video/stm32/stm32_ltdc.c
> index 65c882d9f1..87e5fd54d9 100644
> --- a/drivers/video/stm32/stm32_ltdc.c
> +++ b/drivers/video/stm32/stm32_ltdc.c
> @@ -459,7 +459,10 @@ static int stm32_ltdc_bind(struct udevice *dev)
>  	uc_plat->size = CONFIG_VIDEO_STM32_MAX_XRES *
>  			CONFIG_VIDEO_STM32_MAX_YRES *
>  			(CONFIG_VIDEO_STM32_MAX_BPP >> 3);
> -	dev_dbg(dev, "frame buffer max size %d bytes\n", uc_plat->size);
> +	/* align framebuffer on kernel MMU_SECTION_SIZE = max 2MB for LPAE */
> +	uc_plat->align = SZ_2M;
> +	dev_dbg(dev, "frame buffer max size %d bytes align %x\n",
> +		uc_plat->size, uc_plat->align);
>  
>  	return 0;
>  }
> 
Reviewed-by: Patrice Chotard <patrice.chotard at foss.st.com>
Thanks
Patrice