[PATCH v4] mtd: nand: sunxi: fix OOB handling in ->write_xxx() functions

Boris Brezillon
2015-09-14T08:41:03Z

The USER_DATA register cannot be accessed using byte accessors on A13
SoCs, thus triggering a bug when using memcpy_toio on this register.
Declare an helper macros to convert an OOB buffer into a suitable
USER_DATA value and vice-versa.

This patch also fixes an error in the oob_required logic (some OOB data
are not written even if the user required it) by removing the
oob_required condition, which is perfectly valid since the core already
fill ->oob_poi with FFs when oob_required is false.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: <stable@vger.kernel.org> # 3.19+
Fixes: 1fef62c1423b ("mtd: nand: add sunxi NAND flash controller support")

---
Changes since v3:
- drop the NFC_USER_DATA_TO_BUF() macro

Changes since v2:
- add the NFC_USER_DATA_TO_BUF() macro and rename NFC_USER_DATA() into
NFC_BUF_TO_USER_DATA()
- rework the commit message

Changes since v1:
- drop the !oob_required conditional path
- replace endianness conversions by a macro relying on byte shifting
operations
---
drivers/mtd/nand/sunxi_nand.c | 26 +++++++++-----------------
1 file changed, 9 insertions(+), 17 deletions(-)

diff --git a/drivers/mtd/nand/sunxi_nand.c b/drivers/mtd/nand/sunxi_nand.c
index f97a58d..279cafd 100644
--- a/drivers/mtd/nand/sunxi_nand.c
+++ b/drivers/mtd/nand/sunxi_nand.c
@@ -147,6 +147,10 @@
#define NFC_ECC_MODE GENMASK(15, 12)
#define NFC_RANDOM_SEED GENMASK(30, 16)

+/* NFC_USER_DATA helper macros */
+#define NFC_BUF_TO_USER_DATA(buf) ((buf)[0] | ((buf)[1] << 8) | \
+ ((buf)[2] << 16) | ((buf)[3] << 24))
+
#define NFC_DEFAULT_TIMEOUT_MS 1000

#define NFC_SRAM_SIZE 1024
@@ -646,15 +650,9 @@ static int sunxi_nfc_hw_ecc_write_page(struct mtd_info *mtd,
offset = layout->eccpos[i * ecc->bytes] - 4 + mtd->writesize;

/* Fill OOB data in */
- if (oob_required) {
- tmp = 0xffffffff;
- memcpy_toio(nfc->regs + NFC_REG_USER_DATA_BASE, &tmp,
- 4);
- } else {
- memcpy_toio(nfc->regs + NFC_REG_USER_DATA_BASE,
- chip->oob_poi + offset - mtd->writesize,
- 4);
- }
+ writel(NFC_BUF_TO_USER_DATA(chip->oob_poi +
+ layout->oobfree[i].offset),
+ nfc->regs + NFC_REG_USER_DATA_BASE);

chip->cmdfunc(mtd, NAND_CMD_RNDIN, offset, -1);

@@ -784,14 +782,8 @@ static int sunxi_nfc_hw_syndrome_ecc_write_page(struct mtd_info *mtd,
offset += ecc->size;

/* Fill OOB data in */
- if (oob_required) {
- tmp = 0xffffffff;
- memcpy_toio(nfc->regs + NFC_REG_USER_DATA_BASE, &tmp,
- 4);
- } else {
- memcpy_toio(nfc->regs + NFC_REG_USER_DATA_BASE, oob,
- 4);
- }
+ writel(NFC_BUF_TO_USER_DATA(oob),
+ nfc->regs + NFC_REG_USER_DATA_BASE);

tmp = NFC_DATA_TRANS | NFC_DATA_SWAP_METHOD | NFC_ACCESS_DIR |
(1 << 30);
--
1.9.1