[PATCH V1] drivers:mtd:spi-nor:checkup FSR error bits

[Bean Huo (beanhuo)]

Ping SPI-NOR maintainers again....


>
>Ping SPI-NOR maintainers....
>
>>-----Original Message-----
>>From: Bean Huo (beanhuo)
>>Sent: Samstag, 11. November 2017 21:49
>>To: 'cyrille.pitchen at wedev4u.fr' <cyrille.pitchen at wedev4u.fr>;
>>marek.vasut at gmail.com
>>Cc: 'dwmw2 at infradead.org' <dwmw2 at infradead.org>;
>>computersforpeace at gmail.com; 'linux-mtd at lists.infradead.org' <linux-
>>mtd at lists.infradead.org>; linux-kernel at vger.kernel.org
>>Subject: [PATCH V1] drivers:mtd:spi-nor:checkup FSR error bits
>>
>>For the Micron SPI NOR, when the erase/program operation fails,
>>especially, for the failure results from intending to modify protected
>>space, spi-nor upper layers still get the return which shows the operation
>succeeds.
>>this because spi_nor_fsr_ready() only uses bit.7 to device whether ready.
>>For the most cases, even the error of erase/program occurs, SPI NOR
>>device is still ready. The device ready and the error are two different cases.
>>This patch is to fixup this issue and adding FSR (flag status register)
>>error bits checkup.
>>The FSR(flag status register) is a powerful tool to investigate the
>>staus of device,checking information regarding what is actually doing
>>the memory and detecting possible error conditions.
>>
>>Signed-off-by: beanhuo <beanhuo at micron.com>
>>---
>> drivers/mtd/spi-nor/spi-nor.c | 19 +++++++++++++++++--
>> include/linux/mtd/spi-nor.h   |  6 +++++-
>> 2 files changed, 22 insertions(+), 3 deletions(-)
>>
>>diff --git a/drivers/mtd/spi-nor/spi-nor.c
>>b/drivers/mtd/spi-nor/spi-nor.c index bc266f7..200e814 100644
>>--- a/drivers/mtd/spi-nor/spi-nor.c
>>+++ b/drivers/mtd/spi-nor/spi-nor.c
>>@@ -330,8 +330,23 @@ static inline int spi_nor_fsr_ready(struct spi_nor
>*nor)
>> 	int fsr = read_fsr(nor);
>> 	if (fsr < 0)
>> 		return fsr;
>>-	else
>>-		return fsr & FSR_READY;
>>+
>>+	if (fsr & (FSR_E_ERR | FSR_P_ERR)) {
>>+		if (fsr & FSR_E_ERR)
>>+			dev_err(nor->dev, "Erase operation failed.\n");
>>+		else
>>+			dev_err(nor->dev, "Program operation failed.\n");
>>+
>>+		if (fsr & FSR_PT_ERR)
>>+			dev_err(nor->dev,
>>+			"The operation has attempted to modify the
>>protected"
>>+			"sector or the locked OPT space.\n");
>>+
>>+		nor->write_reg(nor, SPINOR_OP_CLFSR, NULL, 0);
>>+		return -EIO;
>>+	}
>>+
>>+	return fsr & FSR_READY;
>> }
>>
>> static int spi_nor_ready(struct spi_nor *nor) diff --git
>>a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h index
>>d0c66a0..46b5608 100644
>>--- a/include/linux/mtd/spi-nor.h
>>+++ b/include/linux/mtd/spi-nor.h
>>@@ -61,6 +61,7 @@
>> #define SPINOR_OP_RDSFDP	0x5a	/* Read SFDP */
>> #define SPINOR_OP_RDCR		0x35	/* Read configuration register
>>*/
>> #define SPINOR_OP_RDFSR		0x70	/* Read flag status register */
>>+#define SPINOR_OP_CLFSR		0x50	/* Clear flag status register */
>>
>> /* 4-byte address opcodes - used on Spansion and some Macronix flashes.
>*/
>> #define SPINOR_OP_READ_4B	0x13	/* Read data bytes (low
>frequency) */
>>@@ -130,7 +131,10 @@
>> #define EVCR_QUAD_EN_MICRON	BIT(7)	/* Micron Quad I/O */
>>
>> /* Flag Status Register bits */
>>-#define FSR_READY		BIT(7)
>>+#define FSR_READY		BIT(7)	/* Device status, 0 = Busy,1 = Ready */
>>+#define FSR_E_ERR		BIT(5)	/* Erase operation status */
>>+#define FSR_P_ERR		BIT(4)	/* Program operation status */
>>+#define FSR_PT_ERR		BIT(1)	/* Protection error bit */
>>
>> /* Configuration Register bits. */
>> #define CR_QUAD_EN_SPAN		BIT(1)	/* Spansion Quad I/O */
>>--
>>2.7.4
>>