Re: [PATCH] mtd: rawnand: All AC chips have a broken GET_FEATURES(TIMINGS).

[Boris Brezillon <boris.brezillon@bootlin.com>]

On Wed, 20 Jun 2018 11:42:28 +0200
Boris Brezillon <boris.brezillon@bootlin.com> wrote:

> From: Mason Yang <masonccyang@mxic.com.tw>
> 
> Make sure we flag all broken chips as not supporting this feature.
> Also move this logic to a new function to keep things readable.
> 

Crap! I forgot the Fixes and Cc-stable tags. I'll send a new version
soon.

> Signed-off-by: Mason Yang <masonccyang@mxic.com.tw>
> Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
> ---
>  drivers/mtd/nand/raw/nand_macronix.c | 48 +++++++++++++++++++++++++++---------
>  1 file changed, 36 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/mtd/nand/raw/nand_macronix.c b/drivers/mtd/nand/raw/nand_macronix.c
> index 7ed1f87e742a..49c546c97c6f 100644
> --- a/drivers/mtd/nand/raw/nand_macronix.c
> +++ b/drivers/mtd/nand/raw/nand_macronix.c
> @@ -17,23 +17,47 @@
>  
>  #include <linux/mtd/rawnand.h>
>  
> +/*
> + * Macronix AC series does not support using SET/GET_FEATURES to change
> + * the timings unlike what is declared in the parameter page. Unflag
> + * this feature to avoid unnecessary downturns.
> + */
> +static void macronix_nand_fix_broken_get_timings(struct nand_chip *chip)
> +{
> +	unsigned int i;
> +	static const char * const broken_get_timings[] = {
> +		"MX30LF1G18AC",
> +		"MX30LF1G28AC",
> +		"MX30LF2G18AC",
> +		"MX30LF2G28AC",
> +		"MX30LF4G18AC",
> +		"MX30LF4G28AC",
> +		"MX60LF8G18AC",
> +	};
> +
> +	if (!chip->parameters.supports_set_get_features)
> +		return;
> +
> +	for (i = 0; i < ARRAY_SIZE(broken_get_timings); i++) {
> +		if (!strcmp(broken_get_timings[i], chip->parameters.model))
> +			break;
> +	}
> +
> +	if (i == ARRAY_SIZE(broken_get_timings))
> +		return;
> +
> +	bitmap_clear(chip->parameters.get_feature_list,
> +		     ONFI_FEATURE_ADDR_TIMING_MODE, 1);
> +	bitmap_clear(chip->parameters.set_feature_list,
> +		     ONFI_FEATURE_ADDR_TIMING_MODE, 1);
> +}
> +
>  static int macronix_nand_init(struct nand_chip *chip)
>  {
>  	if (nand_is_slc(chip))
>  		chip->bbt_options |= NAND_BBT_SCAN2NDPAGE;
>  
> -	/*
> -	 * MX30LF2G18AC chip does not support using SET/GET_FEATURES to change
> -	 * the timings unlike what is declared in the parameter page. Unflag
> -	 * this feature to avoid unnecessary downturns.
> -	 */
> -	if (chip->parameters.supports_set_get_features &&
> -	    !strcmp("MX30LF2G18AC", chip->parameters.model)) {
> -		bitmap_clear(chip->parameters.get_feature_list,
> -			     ONFI_FEATURE_ADDR_TIMING_MODE, 1);
> -		bitmap_clear(chip->parameters.set_feature_list,
> -			     ONFI_FEATURE_ADDR_TIMING_MODE, 1);
> -	}
> +	macronix_nand_fix_broken_get_timings(chip);
>  
>  	return 0;
>  }