Re: [PATCH] brcmnand: Clear EXT_ADDR error registers in PIO mode

From: Brian Norris
Date: Mon Nov 16 2015 - 19:40:15 EST


+ bcm-kernel-feedback-list

On Mon, Nov 16, 2015 at 10:05:39PM +0000, Simon Arlott wrote:
> If an error occurs in flash above 4GB in PIO mode then the EXT_ADDR
> registers will be set to the location of the error and never cleared.
>
> Reset them to 0 before reading.
>
> Signed-off-by: Simon Arlott <simon@xxxxxxxxxxx>

Patch looks OK. Did you see this problem in practice, or is this just
theoretical? I thought the documentation seemed to suggest these
registers were cleared together with their non-_EXT counterparts. But
implementation definitely trumps documentation for HW.

Brian

> ---
> drivers/mtd/nand/brcmnand/brcmnand.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/mtd/nand/brcmnand/brcmnand.c b/drivers/mtd/nand/brcmnand/brcmnand.c
> index 12c6190..2c8f67f 100644
> --- a/drivers/mtd/nand/brcmnand/brcmnand.c
> +++ b/drivers/mtd/nand/brcmnand/brcmnand.c
> @@ -1400,6 +1400,8 @@ static int brcmnand_read_by_pio(struct mtd_info *mtd, struct nand_chip *chip,
> /* Clear error addresses */
> brcmnand_write_reg(ctrl, BRCMNAND_UNCORR_ADDR, 0);
> brcmnand_write_reg(ctrl, BRCMNAND_CORR_ADDR, 0);
> + brcmnand_write_reg(ctrl, BRCMNAND_UNCORR_EXT_ADDR, 0);
> + brcmnand_write_reg(ctrl, BRCMNAND_CORR_EXT_ADDR, 0);
>
> brcmnand_write_reg(ctrl, BRCMNAND_CMD_EXT_ADDRESS,
> (host->cs << 16) | ((addr >> 32) & 0xffff));
> --
> 2.1.4
>
> --
> Simon Arlott
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