[U-Boot] [PATCH 10/13] sunxi: Make the fastboot buffer larger

[Ian Campbell <ijc@hellion.org.uk>]

On Mon, 2015-08-31 at 16:46 +0200, Maxime Ripard wrote:
> When using fastboot and flashing a larger image such as the main partition
> of a system, the current 32MB limit for the buffer is quite small.

(Apart from rooting/rescuing the odd phone I'm completely unfamiliar
with fastboot, so sorry if this is all obvious).
 
The main partition of a system these days is measured in GB, I think.
So why does going from 32MB to 256MB for the buffer make a useful
difference?

Is there some enormous per-buffer overhead which needs to be amortised?
Or is something else going on?

IOW what is the practical impact of this change?

> Increase it to something that looks decent for such a use case.
> 
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> ---
>  include/configs/sunxi-common.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/include/configs/sunxi-common.h b/include/configs/sunxi
> -common.h
> index 1abf73c31179..710521c617f5 100644
> --- a/include/configs/sunxi-common.h
> +++ b/include/configs/sunxi-common.h
> @@ -363,7 +363,7 @@ extern int soft_i2c_gpio_scl;
>  #ifdef CONFIG_USB_FUNCTION_FASTBOOT
>  #define CONFIG_CMD_FASTBOOT
>  #define CONFIG_FASTBOOT_BUF_ADDR	CONFIG_SYS_LOAD_ADDR
> -#define CONFIG_FASTBOOT_BUF_SIZE	0x2000000
> +#define CONFIG_FASTBOOT_BUF_SIZE	(256 << 20)
>  
>  #define CONFIG_FASTBOOT_FLASH
>  #define CONFIG_FASTBOOT_FLASH_MMC_DEV	0