Re: [PATCH v5 39/50] mtd: nand: omap2: switch to mtd_ooblayout_ops

[Roger Quadros]

On 18/04/16 18:05, Boris Brezillon wrote:
> On Mon, 18 Apr 2016 17:32:49 +0300
> Roger Quadros <rogerq@xxxxxx> wrote:
> 
>> Boris,
>>
>> On 30/03/16 19:14, Boris Brezillon wrote:
>>> Implementing the mtd_ooblayout_ops interface is the new way of exposing
>>> ECC/OOB layout to MTD users.
>>>
>>> Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
>>> ---
>>>  drivers/mtd/nand/omap2.c | 194 +++++++++++++++++++++++++++--------------------
>>>  1 file changed, 113 insertions(+), 81 deletions(-)
>>>
>>> diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
>>> index 4ebf16b..bca154a 100644
>>> --- a/drivers/mtd/nand/omap2.c
>>> +++ b/drivers/mtd/nand/omap2.c
>>> @@ -169,8 +169,6 @@ struct omap_nand_info {
>>>  	u_char				*buf;
>>>  	int					buf_len;
>>>  	struct gpmc_nand_regs		reg;
>>> -	/* generated at runtime depending on ECC algorithm and layout selected */
>>> -	struct nand_ecclayout		oobinfo;
>>>  	/* fields specific for BCHx_HW ECC scheme */
>>>  	struct device			*elm_dev;
>>>  	struct device_node		*of_node;
>>> @@ -1639,19 +1637,108 @@ static bool omap2_nand_ecc_check(struct omap_nand_info *info,
>>>  	return true;
>>>  }
>>>  
>>> +static int omap_ooblayout_ecc(struct mtd_info *mtd, int section,
>>> +			      struct mtd_oob_region *oobregion)
>>> +{
>>> +	struct nand_chip *chip = mtd_to_nand(mtd);
>>> +	int off = chip->options & NAND_BUSWIDTH_16 ?
>>> +		  BADBLOCK_MARKER_LENGTH : 1;
>>
>> IMO "off = 1" is valid only for OMAP_ECC_HAM1_CODE_HW and 8-bit NAND.
>> For all other layouts it is always set to BADBLOCK_MARKER_LENGTH.
> 
> Indeed.
> 
> [...]
> 
>>> -	/* all OOB bytes from oobfree->offset till end off OOB are free */
>>> -	ecclayout->oobfree->length = mtd->oobsize - ecclayout->oobfree->offset;
>>>  	/* check if NAND device's OOB is enough to store ECC signatures */
>>> -	if (mtd->oobsize < (ecclayout->eccbytes + BADBLOCK_MARKER_LENGTH)) {
>>> +	min_oobbytes = (oobbytes_per_step *
>>> +			(mtd->writesize / nand_chip->ecc.size)) +
>>> +		       (nand_chip->options & NAND_BUSWIDTH_16 ?
>>> +			BADBLOCK_MARKER_LENGTH : 1);
>>
>> would it affect this as well?
> 
> And here as well.
> 
> I've generated a patch (see below) fixing those problems.
> 
>>
>>> +	if (mtd->oobsize < min_oobbytes) {
>>>  		dev_err(&info->pdev->dev,
>>>  			"not enough OOB bytes required = %d, available=%d\n",
>>> -			ecclayout->eccbytes, mtd->oobsize);
>>> +			min_oobbytes, mtd->oobsize);
>>>  		err = -EINVAL;
>>>  		goto return_error;
>>>  	}
>>>
>>
>> I will need to test this change with all possible configurations.
>> The number of configurations on OMAP is a bit overwhelming :(.
> 
> Sorry about that, but at least now I have someone who can test it :).
> 
> Thanks,
> 
> Boris
> 
> --->8---
> 
> diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
> index 9b96f56..07d4039 100644
> --- a/drivers/mtd/nand/omap2.c
> +++ b/drivers/mtd/nand/omap2.c
> @@ -1640,9 +1640,13 @@ static bool omap2_nand_ecc_check(struct omap_nand_info *info,
>  static int omap_ooblayout_ecc(struct mtd_info *mtd, int section,
>  			      struct mtd_oob_region *oobregion)
>  {
> -	struct nand_chip *chip = mtd_to_nand(mtd);
> -	int off = chip->options & NAND_BUSWIDTH_16 ?
> -		  BADBLOCK_MARKER_LENGTH : 1;
> +	struct omap_nand_info *info = mtd_to_omap(mtd);
> +	struct nand_chip *chip = &info->nand;
> +	int off = BADBLOCK_MARKER_LENGTH;
> +
> +	if (info->ecc_opt == OMAP_ECC_HAM1_CODE_HW &&
> +	    !(chip->options & NAND_BUSWIDTH_16))
> +		off = 1;
>  
>  	if (section)
>  		return -ERANGE;
> @@ -1656,9 +1660,13 @@ static int omap_ooblayout_ecc(struct mtd_info *mtd, int section,
>  static int omap_ooblayout_free(struct mtd_info *mtd, int section,
>  			       struct mtd_oob_region *oobregion)
>  {
> -	struct nand_chip *chip = mtd_to_nand(mtd);
> -	int off = chip->options & NAND_BUSWIDTH_16 ?
> -		  BADBLOCK_MARKER_LENGTH : 1;
> +	struct omap_nand_info *info = mtd_to_omap(mtd);
> +	struct nand_chip *chip = &info->nand;
> +	int off = BADBLOCK_MARKER_LENGTH;
> +
> +	if (info->ecc_opt == OMAP_ECC_HAM1_CODE_HW &&
> +	    !(chip->options & NAND_BUSWIDTH_16))
> +		off = 1;
>  
>  	if (section)
>  		return -ERANGE;
> @@ -1682,8 +1690,7 @@ static int omap_sw_ooblayout_ecc(struct mtd_info *mtd, int section,
>  				 struct mtd_oob_region *oobregion)
>  {
>  	struct nand_chip *chip = mtd_to_nand(mtd);
> -	int off = chip->options & NAND_BUSWIDTH_16 ?
> -		  BADBLOCK_MARKER_LENGTH : 1;
> +	int off = BADBLOCK_MARKER_LENGTH;
>  
>  	if (section >= chip->ecc.steps)
>  		return -ERANGE;
> @@ -1702,8 +1709,7 @@ static int omap_sw_ooblayout_free(struct mtd_info *mtd, int section,
>  				  struct mtd_oob_region *oobregion)
>  {
>  	struct nand_chip *chip = mtd_to_nand(mtd);
> -	int off = chip->options & NAND_BUSWIDTH_16 ?
> -		  BADBLOCK_MARKER_LENGTH : 1;
> +	int off = BADBLOCK_MARKER_LENGTH;
>  
>  	if (section)
>  		return -ERANGE;
> @@ -1737,7 +1743,7 @@ static int omap_nand_probe(struct platform_device *pdev)
>  	dma_cap_mask_t			mask;
>  	unsigned			sig;
>  	struct resource			*res;
> -	int				min_oobbytes;
> +	int				min_oobbytes = BADBLOCK_MARKER_LENGTH;
>  	int				oobbytes_per_step;
>  
>  	pdata = dev_get_platdata(&pdev->dev);
> @@ -1921,6 +1927,9 @@ static int omap_nand_probe(struct platform_device *pdev)
>  		nand_chip->ecc.correct          = omap_correct_data;
>  		mtd_set_ooblayout(mtd, &omap_ooblayout_ops);
>  		oobbytes_per_step		= nand_chip->ecc.bytes;
> +
> +		if (nand_chip->options & NAND_BUSWIDTH_16)
> +			min_oobbytes		= 1;

Shouldn't this have been
		if (!(nand_chip->options & NAND_BUSWIDTH_16)
			min_oobbytes		= 1;
?

>  		break;
>  
>  	case OMAP_ECC_BCH4_CODE_HW_DETECTION_SW:
> @@ -2038,10 +2047,8 @@ static int omap_nand_probe(struct platform_device *pdev)
>  	}
>  
>  	/* check if NAND device's OOB is enough to store ECC signatures */
> -	min_oobbytes = (oobbytes_per_step *
> -			(mtd->writesize / nand_chip->ecc.size)) +
> -		       (nand_chip->options & NAND_BUSWIDTH_16 ?
> -			BADBLOCK_MARKER_LENGTH : 1);
> +	min_oobbytes += (oobbytes_per_step *
> +			 (mtd->writesize / nand_chip->ecc.size));
>  	if (mtd->oobsize < min_oobbytes) {
>  		dev_err(&info->pdev->dev,
>  			"not enough OOB bytes required = %d, available=%d\n",
> 

After the above changes BCH with HW ECC worked fine but BCH with SW ECC still failed.
I had to fix it up with the below patch. This is mainly because chip->ecc.steps wasn't
yet initialized before calling nand_bch_init().

After the below patch it worked fine with bch4 (hw & sw), bch8 (hw & sw) and ham1.
I couldn't yet verify bch16 though.

--cheers,
-roger

diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c
index db22c01..1b1a804 100644
--- a/drivers/mtd/nand/omap2.c
+++ b/drivers/mtd/nand/omap2.c
@@ -1692,7 +1692,7 @@ static int omap_sw_ooblayout_ecc(struct mtd_info *mtd, int section,
 	struct nand_chip *chip = mtd_to_nand(mtd);
 	int off = BADBLOCK_MARKER_LENGTH;
 
-	if (section >= chip->ecc.steps)
+	if (section >= mtd->writesize / chip->ecc.size)	/* ecc steps */
 		return -ERANGE;
 
 	/*
@@ -1711,7 +1711,7 @@ static int omap_sw_ooblayout_free(struct mtd_info *mtd, int section,
 	struct nand_chip *chip = mtd_to_nand(mtd);
 	int off = BADBLOCK_MARKER_LENGTH;
 
-	if (section)
+	if (section >= mtd->writesize / chip->ecc.size) /* ecc steps */
 		return -ERANGE;
 
 	/*
-- 
2.5.0