[U-Boot-Users] [PATCH] mips: tolerate the MIPS 'CFG_HZ' values in the MHZ range for NAND delays

Scott Wood
2008-05-19T20:26:54Z

Jason McMullan wrote:
> Rewrite the nand_wait() FL_ERASING case to handle CFG_HZ values in the
> MHZ range. This is needed for mips processors, as the timer's timebase
> ticks at CPU clock frequency.

Even though it's MIPS that needs it, it should be flagged as a NAND
patch since that's the code it touches.

> diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
> index 2da1d46..ac690ac 100644
> --- a/drivers/mtd/nand/nand_base.c
> +++ b/drivers/mtd/nand/nand_base.c
> @@ -837,10 +837,17 @@ static int nand_wait(struct mtd_info *mtd, struct nand_chip *this, int state)
> {
> unsigned long timeo;
>
> +#if CFG_HZ > 100000
> + if (state == FL_ERASING)
> + timeo = (CFG_HZ / 1000) * 400;
> + else
> + timeo = (CFG_HZ / 1000) * 20;
> +#else
> if (state == FL_ERASING)
> timeo = (CFG_HZ * 400) / 1000;
> else
> timeo = (CFG_HZ * 20) / 1000;
> +#endif

How about this?

if (state == FL_ERASING)
timeo = CFG_HZ * 2 / 5;
else
timeo = CFG_HZ / 50

If we have CFG_HZ values that are within a factor of 2 of wrapping
around, the platform should probably do some downward scaling (or we
should think about 64-bit timestamps)...

-Scott