On 2018-05-07 13:58, Boris Brezillon wrote:
On Thu, 3 May 2018 17:50:31 +0530
Abhishek Sahu <absahu@xxxxxxxxxxxxxx> wrote:
Currently the driver uses the ECC strength specified in DT.
The QPIC/EBI2 NAND supports 4 or 8-bit ECC correction. The same
kind of board can have different NAND parts so use the ECC
strength from device parameters if it is not specified in DT.
Signed-off-by: Abhishek Sahu <absahu@xxxxxxxxxxxxxx>
---
* Changes from v1:
1. Removed the custom logic and used the helper fuction.
drivers/mtd/nand/raw/qcom_nandc.c | 31
++++++++++++++++++++++---------
1 file changed, 22 insertions(+), 9 deletions(-)
diff --git a/drivers/mtd/nand/raw/qcom_nandc.c
b/drivers/mtd/nand/raw/qcom_nandc.c
index b554fb6..a8d71ce 100644
--- a/drivers/mtd/nand/raw/qcom_nandc.c
+++ b/drivers/mtd/nand/raw/qcom_nandc.c
@@ -2315,13 +2315,21 @@ static int qcom_nand_ooblayout_free(struct
mtd_info *mtd, int section,
.free = qcom_nand_ooblayout_free,
};
+static int
+qcom_nandc_calc_ecc_bytes(int step_size, int strength)
+{
+ return strength == 4 ? 12 : 16;
+}
+NAND_ECC_CAPS_SINGLE(qcom_nandc_ecc_caps, qcom_nandc_calc_ecc_bytes,
+ NANDC_STEP_SIZE, 4, 8);
+
static int qcom_nand_host_setup(struct qcom_nand_host *host)
{
struct nand_chip *chip = &host->chip;
struct mtd_info *mtd = nand_to_mtd(chip);
struct nand_ecc_ctrl *ecc = &chip->ecc;
struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
- int cwperpage, bad_block_byte;
+ int cwperpage, bad_block_byte, ret;
bool wide_bus;
int ecc_mode = 1;
@@ -2334,8 +2342,20 @@ static int qcom_nand_host_setup(struct
qcom_nand_host *host)
return -EINVAL;
}
+ cwperpage = mtd->writesize / ecc->size;
Looks like you're still expecting nand-ecc-step-size to be defined in
the DT, which does not really make sense since you only support one
size: NANDC_STEP_SIZE.
You should remove the
if (ecc->size != NANDC_STEP_SIZE) {
dev_err(nandc->dev, "invalid ecc size\n");
return -EINVAL;
}
block, then do:
cwperpage = mtd->writesize / NANDC_STEP_SIZE;
and finally let the nand_ecc_param_setup() function choose the best
config for you.
Correct Boris.
It only supports one step size so we can remove this DT
property. I will make the changes.
+
+ /*
+ * Each CW has 4 available OOB bytes which will be protected with
ECC
+ * so remaining bytes can be used for ECC.
+ */
+ ret = nand_ecc_param_setup(chip, &qcom_nandc_ecc_caps,
+ mtd->oobsize - (cwperpage << 2));
Please stop doing useless optimizations like. That brings nothing and
obfuscates the code a bit more. You say in the comment that each
codeword has 4 protected OOB bytes that can be used by the upper layer,
so just do (cwperpage * 4) and let gcc optimize that for you.
Sure. I will change it.
Thanks,
Abhishek
+ if (ret) {
+ dev_err(nandc->dev, "No valid ecc settings possible\n");
+ return ret;
+ }
+
wide_bus = chip->options & NAND_BUSWIDTH_16 ? true : false;
-
if (ecc->strength >= 8) {
/* 8 bit ECC defaults to BCH ECC on all platforms */
host->bch_enabled = true;
@@ -2403,7 +2423,6 @@ static int qcom_nand_host_setup(struct
qcom_nand_host *host)
mtd_set_ooblayout(mtd, &qcom_nand_ooblayout_ops);
- cwperpage = mtd->writesize / ecc->size;
nandc->max_cwperpage = max_t(unsigned int, nandc->max_cwperpage,
cwperpage);
@@ -2419,12 +2438,6 @@ static int qcom_nand_host_setup(struct
qcom_nand_host *host)
* for 8 bit ECC
*/
host->cw_size = host->cw_data + ecc->bytes;
-
- if (ecc->bytes * (mtd->writesize / ecc->size) > mtd->oobsize) {
- dev_err(nandc->dev, "ecc data doesn't fit in OOB area\n");
- return -EINVAL;
- }
-
bad_block_byte = mtd->writesize - host->cw_size * (cwperpage - 1) +
1;
host->cfg0 = (cwperpage - 1) << CW_PER_PAGE
--
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