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

From: Boris Brezillon
Date: Thu Aug 10 2017 - 05:43:05 EST


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)

>
> /* 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.

> /*
> * 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;
> }