[U-Boot] [PATCH] nand_base: Add timeout for NAND reset command

[Scott Wood]

Peter Tyser wrote:
> +/*
> + * CONFIG_SYS_NAND_RESET_CNT is used as a timeout mechanism when resetting
> + * a flash.  NAND flash is initialized prior to interrupts so standard timers
> + * can't be used.  CONFIG_SYS_NAND_RESET_CNT should be set to a value
> + * which is greater than (max NAND reset time / NAND status read time).
> + * A conservative default of 200000 (500 us / 25 ns) is used as a default.
> + */
> +#ifndef CONFIG_SYS_NAND_RESET_CNT
> +#define CONFIG_SYS_NAND_RESET_CNT 200000
> +#endif

Where does 25 ns come from?  Should the timeout be in terms of real time 
rather than iterations (we use get_ticks() for this purpose in 
fsl_elbc_nand.c)?

-Scott