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

[Bean Huo (beanhuo)]

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
>