[PATCH v2 2/3] mtd: rawnand: sunxi: support randomized OOB formats
From: James Hilliard <hidden>
Date: 2026-09-04 21:23:58
Also in:
linux-arm-kernel, linux-sunxi, lkml
Subsystem:
memory technology devices (mtd), nand flash subsystem, the rest · Maintainers:
Miquel Raynal, Richard Weinberger, Vignesh Raghavendra, Linus Torvalds
The controller randomizer covers the bad block marker along with the rest of the OOB data. The driver currently compensates the marker bytes before writes and after reads so that they remain plain on flash. Allwinner NAND firmware instead stores the marker through the randomizer. Media using that format appears to contain bad blocks unless the randomizer is enabled while reading the marker. Honor the allwinner,randomized-oob property by marking the NAND as requiring scrambling during normal hardware-ECC transfers and leaving the marker in the randomizer data stream. Keep the existing plain marker behavior when the property is absent. Reject the property with software or disabled ECC because those paths do not operate the controller randomizer. MTD_OPS_RAW behavior remains unchanged: raw accesses bypass both ECC and randomization and expose the physical representation. The raw-NAND core's bad-block and flash-BBT paths use decoded accesses and therefore continue through the hardware-ECC/randomizer path. This changes marker handling on all supported controllers; the H6/H616 protected user-data placement is handled separately. Signed-off-by: James Hilliard <redacted> --- drivers/mtd/nand/raw/sunxi_nand.c | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-)
diff --git a/drivers/mtd/nand/raw/sunxi_nand.c b/drivers/mtd/nand/raw/sunxi_nand.c
index 83666dd6cb2a..c1246a9268ca 100644
--- a/drivers/mtd/nand/raw/sunxi_nand.c
+++ b/drivers/mtd/nand/raw/sunxi_nand.c@@ -265,6 +265,7 @@ struct sunxi_nfc_timings { * @clk_rate: clk_rate required for this NAND chip * @timing_cfg: TIMING_CFG register value for this NAND chip * @timing_ctl: TIMING_CTL register value for this NAND chip + * @randomized_oob: use the randomized normal-page OOB format * @nsels: number of CS lines required by the NAND chip * @sels: array of CS lines descriptions * @user_data_bytes: array of user data lengths for all ECC steps
@@ -277,6 +278,7 @@ struct sunxi_nand_chip { u32 timing_cfg; u32 timing_ctl; u8 *user_data_bytes; + bool randomized_oob; int nsels; struct sunxi_nand_chip_sel sels[] __counted_by(nsels); };
@@ -945,8 +947,9 @@ static void sunxi_nfc_hw_ecc_get_prot_oob_bytes(struct nand_chip *nand, u8 *oob, } } - /* De-randomize the Bad Block Marker. */ - if (bbm && (nand->options & NAND_NEED_SCRAMBLING)) + /* Undo hardware de-randomization for a plain on-flash BBM. */ + if (bbm && (nand->options & NAND_NEED_SCRAMBLING) && + !sunxi_nand->randomized_oob) sunxi_nfc_randomize_bbm(nand, page, oob); }
@@ -1006,8 +1009,9 @@ static void sunxi_nfc_hw_ecc_set_prot_oob_bytes(struct nand_chip *nand, unsigned int user_data_sz = sunxi_nfc_user_data_sz(sunxi_nand, step); u8 user_data[SUNXI_NFC_MAX_USER_DATA_SZ] = {}; - /* Randomize the Bad Block Marker. */ - if (bbm && (nand->options & NAND_NEED_SCRAMBLING)) { + /* Pre-randomize the BBM so the hardware writes it plain on flash. */ + if (bbm && (nand->options & NAND_NEED_SCRAMBLING) && + !sunxi_nand->randomized_oob) { memcpy(user_data, oob, user_data_sz); sunxi_nfc_randomize_bbm(nand, page, user_data); oob = user_data;
@@ -2229,6 +2233,8 @@ static int sunxi_nand_hw_ecc_ctrl_init(struct nand_chip *nand, static int sunxi_nand_attach_chip(struct nand_chip *nand) { + struct sunxi_nand_chip *sunxi_nand = to_sunxi_nand(nand); + struct sunxi_nfc *nfc = to_sunxi_nfc(nand->controller); const struct nand_ecc_props *requirements = nanddev_get_ecc_requirements(&nand->base); struct nand_ecc_ctrl *ecc = &nand->ecc;
@@ -2238,6 +2244,14 @@ static int sunxi_nand_attach_chip(struct nand_chip *nand) if (nand->bbt_options & NAND_BBT_USE_FLASH) nand->bbt_options |= NAND_BBT_NO_OOB; + if (sunxi_nand->randomized_oob && + ecc->engine_type != NAND_ECC_ENGINE_TYPE_ON_HOST) + return dev_err_probe(nfc->dev, -EINVAL, + "Allwinner OOB format requires controller ECC\n"); + + if (sunxi_nand->randomized_oob) + nand->options |= NAND_NEED_SCRAMBLING; + if (nand->options & NAND_NEED_SCRAMBLING) nand->options |= NAND_NO_SUBPAGE_WRITE;
@@ -2467,6 +2481,9 @@ static int sunxi_nand_chip_init(struct device *dev, struct sunxi_nfc *nfc, if (!sunxi_nand) return -ENOMEM; + sunxi_nand->randomized_oob = + of_property_read_bool(np, "allwinner,randomized-oob"); + sunxi_nand->nsels = nsels; for (i = 0; i < nsels; i++) {
--
2.53.0