From 8796680277f4b231386fbc6e8a1ccae91d9fcbe8 Mon Sep 17 00:00:00 2001 From: Daniel Golle Date: Thu, 7 Jun 2018 01:51:58 +0200 Subject: [PATCH] ramips: fix reboot with W25Q256 with 4-address-mode enabled Some board vendors actually changed the loader to expect the chip to come up in 4-address-mode and flipped the ADP bit in the flash chip's configuration register which makes it come up in 4-address-mode. Hence it doesn't make sense to avoid switching to 4-address-mode on those boards but the opposite as otherwise reboot hangs eg. on the WrtNode2 boards. Fix this by checking the ADP register and only using SPI_NOR_4B_READ_OP on chips which have ADP==0 (come up in 3-byte mode). See also datasheet section 7.1.11 Power Up Address Mode (ADP) Fixes: 22d982ea0 ("ramips: add support for switching between 3-byte and 4-byte addressing on w25q256 flash") Signed-off-by: Daniel Golle --- ...spi-nor-w25q256-respect-default-mode.patch | 73 +++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 target/linux/ramips/patches-4.14/0054-mtd-spi-nor-w25q256-respect-default-mode.patch diff --git a/target/linux/ramips/patches-4.14/0054-mtd-spi-nor-w25q256-respect-default-mode.patch b/target/linux/ramips/patches-4.14/0054-mtd-spi-nor-w25q256-respect-default-mode.patch new file mode 100644 index 0000000000..568d61db91 --- /dev/null +++ b/target/linux/ramips/patches-4.14/0054-mtd-spi-nor-w25q256-respect-default-mode.patch @@ -0,0 +1,73 @@ +--- a/drivers/mtd/spi-nor/spi-nor.c ++++ b/drivers/mtd/spi-nor/spi-nor.c +@@ -142,20 +142,29 @@ static int read_fsr(struct spi_nor *nor) + * location. Return the configuration register value. + * Returns negative if error occurred. + */ +-static int read_cr(struct spi_nor *nor) ++static int _read_cr(struct spi_nor *nor, u8 reg) + { + int ret; + u8 val; + +- ret = nor->read_reg(nor, SPINOR_OP_RDCR, &val, 1); ++ ret = nor->read_reg(nor, reg, &val, 1); + if (ret < 0) { +- dev_err(nor->dev, "error %d reading CR\n", ret); ++ dev_err(nor->dev, "error %d reading %s\n", ret, ++ (reg==SPINOR_OP_RDCR)?"CR":"XCR"); + return ret; + } + + return val; + } + ++static inline int read_cr(struct spi_nor *nor) { ++ return _read_cr(nor, SPINOR_OP_RDCR); ++} ++ ++static inline int read_xcr(struct spi_nor *nor) { ++ return _read_cr(nor, SPINOR_OP_RDXCR); ++} ++ + /* + * Write status register 1 byte + * Returns negative if error occurred. +@@ -2878,9 +2887,16 @@ int spi_nor_scan(struct spi_nor *nor, co + } else if (mtd->size > 0x1000000) { + /* enable 4-byte addressing if the device exceeds 16MiB */ + nor->addr_width = 4; +- if (info->flags & SPI_NOR_4B_READ_OP) +- spi_nor_set_4byte_read(nor, info); +- else if (JEDEC_MFR(info) == SNOR_MFR_SPANSION || ++ if (info->flags & SPI_NOR_4B_READ_OP) { ++ if (JEDEC_MFR(info) == SNOR_MFR_WINBOND) { ++ ret = read_xcr(nor); ++ if (!(ret > 0 && (ret & XCR_DEF_4B_ADDR_MODE))) ++ spi_nor_set_4byte_read(nor, info); ++ else ++ set_4byte(nor, info, 1); ++ } else ++ spi_nor_set_4byte_read(nor, info); ++ } else if (JEDEC_MFR(info) == SNOR_MFR_SPANSION || + info->flags & SPI_NOR_4B_OPCODES) + spi_nor_set_4byte_opcodes(nor, info); + else +--- a/include/linux/mtd/spi-nor.h ++++ b/include/linux/mtd/spi-nor.h +@@ -103,6 +103,7 @@ + #define SPINOR_OP_EN4B 0xb7 /* Enter 4-byte mode */ + #define SPINOR_OP_EX4B 0xe9 /* Exit 4-byte mode */ + #define SPINOR_OP_WREAR 0xc5 /* Write extended address register */ ++#define SPINOR_OP_RDXCR 0x15 /* Read extended configuration register */ + + /* Used for Spansion flashes only. */ + #define SPINOR_OP_BRWR 0x17 /* Bank register write */ +@@ -135,6 +136,7 @@ + + /* Configuration Register bits. */ + #define CR_QUAD_EN_SPAN BIT(1) /* Spansion Quad I/O */ ++#define XCR_DEF_4B_ADDR_MODE BIT(1) /* Winbond 4B mode default */ + + /* Status Register 2 bits. */ + #define SR2_QUAD_EN_BIT7 BIT(7) -- 2.25.1