From mboxrd@z Thu Jan  1 00:00:00 1970
From: Scott Wood <scottwood@freescale.com>
Date: Wed, 04 Feb 2009 13:54:02 -0600
Subject: [U-Boot] [PATCH] nand_base: Add timeout for NAND reset command
In-Reply-To: <1233776842-23379-1-git-send-email-ptyser@xes-inc.com>
References: <1233776842-23379-1-git-send-email-ptyser@xes-inc.com>
Message-ID: <4989F25A.6090400@freescale.com>
List-Id: <u-boot.lists.denx.de>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
To: u-boot@lists.denx.de

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