Re: [PATCH v2 1/2] mtd: rawnand: qcom: Fix broken erase in misc_cmd_type in exec_op

From: Manivannan Sadhasivam
Date: Tue Mar 26 2024 - 03:25:28 EST


On Mon, Mar 25, 2024 at 11:30:47AM +0100, Christian Marangi wrote:
> misc_cmd_type in exec_op have multiple problems. With commit a82990c8a409
> ("mtd: rawnand: qcom: Add read/read_start ops in exec_op path") it was
> reworked and generalized but actually broke the handling of the
> ERASE_BLOCK command.
>
> Additional logic was added to the erase command cycle without clear
> explaination causing the erase command to be broken on testing it on
> a ipq806x nandc.
>
> Fix the erase command by reverting the additional logic and only adding
> the NAND_DEV0_CFG0 additional call (required for erase command).
>
> Fixes: a82990c8a409 ("mtd: rawnand: qcom: Add read/read_start ops in exec_op path")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Christian Marangi <ansuelsmth@xxxxxxxxx>
> ---
> Changes v2:
> - Split this and rework commit description and title
>
> drivers/mtd/nand/raw/qcom_nandc.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c
> index b079605c84d3..19d76e345a49 100644
> --- a/drivers/mtd/nand/raw/qcom_nandc.c
> +++ b/drivers/mtd/nand/raw/qcom_nandc.c
> @@ -2830,9 +2830,8 @@ static int qcom_misc_cmd_type_exec(struct nand_chip *chip, const struct nand_sub
> nandc_set_reg(chip, NAND_EXEC_CMD, 1);
>
> write_reg_dma(nandc, NAND_FLASH_CMD, instrs, NAND_BAM_NEXT_SGL);
> - (q_op.cmd_reg == OP_BLOCK_ERASE) ? write_reg_dma(nandc, NAND_DEV0_CFG0,
> - 2, NAND_BAM_NEXT_SGL) : read_reg_dma(nandc,
> - NAND_FLASH_STATUS, 1, NAND_BAM_NEXT_SGL);
> + if (q_op.cmd_reg == OP_BLOCK_ERASE)
> + write_reg_dma(nandc, NAND_DEV0_CFG0, 2, NAND_BAM_NEXT_SGL);

So this only avoids the call to, 'read_reg_dma(nandc, NAND_FLASH_STATUS, 1,
NAND_BAM_NEXT_SGL)' if q_op.cmd_reg != OP_BLOCK_ERASE. But for q_op.cmd_reg ==
OP_BLOCK_ERASE, the result is the same.

I'm wondering how it results in fixing the OP_BLOCK_ERASE command.

Can you share the actual issue that you are seeing? Like error logs etc...

- Mani

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