Miquel Raynal [off-list ref] wrote on Tue, 15 Sep 2020
10:07:28 +0200:

Hi Yifeng,

I am very sorry for the delay it took me to review this driver, but
there are still some small incoherences IMHO, see below.

One last important comment below

quoted

+static int rk_nfc_attach_chip(struct nand_chip *chip)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	struct device *dev = mtd->dev.parent;
+	struct rk_nfc *nfc = nand_get_controller_data(chip);
+	struct rk_nfc_nand_chip *rknand = to_rknand(chip);
+	struct nand_ecc_ctrl *ecc = &chip->ecc;
+	int len;
+	int ret;
+
+	if (chip->options & NAND_BUSWIDTH_16) {
+		dev_err(dev, "16 bits bus width not supported");
+		return -EINVAL;
+	}
+
+	if (ecc->mode != NAND_ECC_HW)
+		return 0;
+
+	ret = rk_nfc_ecc_init(dev, mtd);
+	if (ret)
+		return ret;
+	rknand->spare_per_sector = ecc->bytes + NFC_SYS_DATA_SIZE;
+	rknand->metadata_size = NFC_SYS_DATA_SIZE * ecc->steps;
+
+	if (rknand->metadata_size < NFC_SYS_DATA_SIZE + 2) {
+		dev_err(dev,
+			"Driver needs at least %d bytes of meta data\n",
+			NFC_SYS_DATA_SIZE + 2);
+		return -EIO;
+	}
+	/* Check buffer first, avoid duplicate alloc buffer. */
+	if (nfc->buffer)
+		return 0;  

You can't do that this way: what if the first mtd to be registered uses
a smaller page size than the second?

quoted

+
+	len = mtd->writesize + mtd->oobsize;
+	nfc->buffer = devm_kzalloc(dev, len, GFP_KERNEL | GFP_DMA);

I don't think this fits your purpose. You should probably allocate with
kzalloc or perhaps dma_alloc*.

Then, you'll also have to free this memory.

quoted

+	if (!nfc->buffer)
+		return -ENOMEM;
+
+	nfc->page_buf = nfc->buffer;
+	len = ecc->steps * NFC_MAX_OOB_PER_STEP;
+	nfc->oob_buf = devm_kzalloc(dev, len, GFP_KERNEL | GFP_DMA);
+	if (!nfc->oob_buf) {
+		nfc->buffer = NULL;
+		nfc->oob_buf = NULL;  

I don't think this is needed

quoted

+		return -ENOMEM;
+	}
+
+	chip->ecc.write_page_raw = rk_nfc_write_page_raw;
+	chip->ecc.write_page = rk_nfc_write_page_hwecc;
+	chip->ecc.write_oob_raw = rk_nfc_write_oob_std;
+	chip->ecc.write_oob = rk_nfc_write_oob_std;
+
+	chip->ecc.read_page_raw = rk_nfc_read_page_raw;
+	chip->ecc.read_page = rk_nfc_read_page_hwecc;
+	chip->ecc.read_oob_raw = rk_nfc_read_oob_std;
+	chip->ecc.read_oob = rk_nfc_read_oob_std;  

I don't like the _std prefix, but it should be gone when splitting the
functions as advised.

quoted

+
+	return 0;
+}

Thanks,
Miquèl

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