Re: [PATCH v3 01/20] mtd: nand: qcom: program NAND_DEV_CMD_VLD register

From: Abhishek Sahu
Date: Thu Aug 10 2017 - 06:31:28 EST


On 2017-08-10 15:12, Boris Brezillon wrote:
Le Sat, 5 Aug 2017 21:49:39 +0530,
Abhishek Sahu <absahu@xxxxxxxxxxxxxx> a Ãcrit :

The NAND page read fails without complete boot chain since
NAND_DEV_CMD_VLD value is not proper. The default power on reset
value for this register is

0xe - ERASE_START_VALID | WRITE_START_VALID | READ_STOP_VALID

The READ_START_VALID should be enabled for sending PAGE_READ
command. READ_STOP_VALID should be cleared since normal NAND
page read does not require READ_STOP command.

Fixes: c76b78d8ec05a ("mtd: nand: Qualcomm NAND controller driver")
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Archit Taneja <architt@xxxxxxxxxxxxxx>
Signed-off-by: Abhishek Sahu <absahu@xxxxxxxxxxxxxx>
---
drivers/mtd/nand/qcom_nandc.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/qcom_nandc.c b/drivers/mtd/nand/qcom_nandc.c
index 0289f09..7406019 100644
--- a/drivers/mtd/nand/qcom_nandc.c
+++ b/drivers/mtd/nand/qcom_nandc.c
@@ -110,6 +110,10 @@

/* NAND_DEV_CMD_VLD bits */
#define READ_START_VLD 0
+#define READ_STOP_VALID 1
+#define WRITE_START_VALID 2
+#define ERASE_START_VALID 3
+#define SEQ_READ_START_VLD 4

Why not

#define READ_START_VLD BIT(0)
#define READ_STOP_VALID BIT(1)
#define WRITE_START_VALID BIT(2)
#define ERASE_START_VALID BIT(3)
#define SEQ_READ_START_VLD BIT(4)


Sure. we can change to use BIT macro.

We are using READ_START_VLD only at one place so will replace in
current code from

/* configure CMD1 and VLD for ONFI param probing */
nandc_set_reg(nandc, NAND_DEV_CMD_VLD,
(nandc->vld & ~(1 << READ_START_VLD))
| 0 << READ_START_VLD);
to

nandc_set_reg(nandc, NAND_DEV_CMD_VLD, nandc->vld & ~READ_START_VLD)


/* NAND_EBI2_ECC_BUF_CFG bits */
#define NUM_STEPS 0
@@ -148,6 +152,12 @@
#define FETCH_ID 0xb
#define RESET_DEVICE 0xd

+/* Default Value for NAND_DEV_CMD_VLD */
+#define NAND_DEV_CMD_VLD_VAL (BIT(READ_START_VLD) | \
+ BIT(WRITE_START_VALID) | \
+ BIT(ERASE_START_VALID) | \
+ BIT(SEQ_READ_START_VLD))
+

and then:

#define NAND_DEV_CMD_VLD_VAL (READ_START_VLD | \
WRITE_START_VALID | \
ERASE_START_VALID | \
SEQ_READ_START_VLD)

BTW, can you use consistent suffixes? Sometime definitions are suffixed
with _VLD and others are suffixed with _VALID.


Sure. I will change all the names to _VLD.

/*
* the NAND controller performs reads/writes with ECC in 516 byte chunks.
* the driver calls the chunks 'step' or 'codeword' interchangeably
@@ -1995,13 +2005,14 @@ static int qcom_nandc_setup(struct qcom_nand_controller *nandc)
{
/* kill onenand */
nandc_write(nandc, SFLASHC_BURST_CFG, 0);
+ nandc_write(nandc, NAND_DEV_CMD_VLD, NAND_DEV_CMD_VLD_VAL);

/* enable ADM DMA */
nandc_write(nandc, NAND_FLASH_CHIP_SELECT, DM_EN);

/* save the original values of these registers */
nandc->cmd1 = nandc_read(nandc, NAND_DEV_CMD1);
- nandc->vld = nandc_read(nandc, NAND_DEV_CMD_VLD);
+ nandc->vld = NAND_DEV_CMD_VLD_VAL;

return 0;
}