[PATCH v1 3/5] mtd: rawnand: meson: check buffer length

[Arseniy Krasnov]

With this chip, buffer length is limited by hardware, so check it before
command execution to avoid length trim.

Signed-off-by: Arseniy Krasnov <AVKrasnov at sberdevices.ru>
---
 drivers/mtd/nand/raw/meson_nand.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/mtd/nand/raw/meson_nand.c b/drivers/mtd/nand/raw/meson_nand.c
index 45b53d420aed..f84a10238e4d 100644
--- a/drivers/mtd/nand/raw/meson_nand.c
+++ b/drivers/mtd/nand/raw/meson_nand.c
@@ -543,6 +543,9 @@ static int meson_nfc_read_buf(struct nand_chip *nand, u8 *buf, int len)
 	u32 cmd;
 	u8 *info;
 
+	if (len > NFC_CMD_RAW_LEN)
+		return -EINVAL;
+
 	info = kzalloc(PER_INFO_BYTE, GFP_KERNEL);
 	if (!info)
 		return -ENOMEM;
@@ -571,6 +574,9 @@ static int meson_nfc_write_buf(struct nand_chip *nand, u8 *buf, int len)
 	int ret = 0;
 	u32 cmd;
 
+	if (len > NFC_CMD_RAW_LEN)
+		return -EINVAL;
+
 	ret = meson_nfc_dma_buffer_setup(nand, buf, len, NULL,
 					 0, DMA_TO_DEVICE);
 	if (ret)
@@ -1269,6 +1275,7 @@ static int meson_nand_attach_chip(struct nand_chip *nand)
 	struct meson_nfc_nand_chip *meson_chip = to_meson_nand(nand);
 	struct mtd_info *mtd = nand_to_mtd(nand);
 	int nsectors = mtd->writesize / 1024;
+	int raw_writesize;
 	int ret;
 
 	if (!mtd->name) {
@@ -1280,6 +1287,13 @@ static int meson_nand_attach_chip(struct nand_chip *nand)
 			return -ENOMEM;
 	}
 
+	raw_writesize = mtd->writesize + mtd->oobsize;
+	if (raw_writesize > NFC_CMD_RAW_LEN) {
+		dev_err(nfc->dev, "too big write size in raw mode: %d > %ld\n",
+			raw_writesize, NFC_CMD_RAW_LEN);
+		return -EINVAL;
+	}
+
 	if (nand->bbt_options & NAND_BBT_USE_FLASH)
 		nand->bbt_options |= NAND_BBT_NO_OOB;
 
-- 
2.35.0