Re: [PATCH 2/2] mtd: rawnand: qcom: Fix onfi param page read

[Md Sadre Alam <quic_mdalam@xxxxxxxxxxx>]

On 11/20/2024 12:36 PM, Manivannan Sadhasivam wrote:
> On Tue, Nov 19, 2024 at 02:50:58PM +0530, Md Sadre Alam wrote:
> > For QPIC V2 onwards there is a separate register to read
> > last code word "QPIC_NAND_READ_LOCATION_LAST_CW_n".
> >
> > qcom_param_page_type_exec() is used to read only one code word
> > If we will configure number of code words to 1 in QPIC_NAND_DEV0_CFG0
>
> No 'we' in commit message. Also use imperative tone.
Ok
> > register then QPIC controller thinks its reading the last code word,
> > since we are having separate register to read the last code word,
> > we have to configure "QPIC_NAND_READ_LOCATION_LAST_CW_n" register
> > to fetch data from QPIC buffer to system memory.
> >
> > Also there is minimum size to fetch the data from device to QPIC buffer
> > is 512-bytes. If size is less than 512-bytes the data will not be
> > protected by ECC as per QPIC standard. So while reading onfi parameter
> > page from NAND device setting nandc->buf_count = 512.
>
> This is a separate fix and should be in a separate patch.
Ok
> > Fixes: 89550beb098e ("mtd: rawnand: qcom: Implement exec_op()")
>
> Please describe the impact of the issue. Add relevant failure messages, affected
> SoC names etc...
Sure, Will update in next revision.
> Finally, you should also CC stable list to backport the fixes.
Ok
> - Mani
>
> > Signed-off-by: Md Sadre Alam <quic_mdalam@xxxxxxxxxxx>
> > ---
> >   drivers/mtd/nand/raw/qcom_nandc.c | 14 +++++++++++---
> >   1 file changed, 11 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c
> > index 34ee8555fb8a..6487f2126833 100644
> > --- a/drivers/mtd/nand/raw/qcom_nandc.c
> > +++ b/drivers/mtd/nand/raw/qcom_nandc.c
> > @@ -2859,7 +2859,12 @@ static int qcom_param_page_type_exec(struct nand_chip *chip,  const struct nand_
> >   	const struct nand_op_instr *instr = NULL;
> >   	unsigned int op_id = 0;
> >   	unsigned int len = 0;
> > -	int ret;
> > +	int ret, reg_base;
> > +
> > +	reg_base = NAND_READ_LOCATION_0;
> > +
> > +	if (nandc->props->qpic_v2)
> > +		reg_base = NAND_READ_LOCATION_LAST_CW_0;
> >   
> >   	ret = qcom_parse_instructions(chip, subop, &q_op);
> >   	if (ret)
> > @@ -2911,14 +2916,17 @@ static int qcom_param_page_type_exec(struct nand_chip *chip,  const struct nand_
> >   	op_id = q_op.data_instr_idx;
> >   	len = nand_subop_get_data_len(subop, op_id);
> >   
> > -	nandc_set_read_loc(chip, 0, 0, 0, len, 1);
> > +	if (nandc->props->qpic_v2)
> > +		nandc_set_read_loc_last(chip, reg_base, 0, len, 1);
> > +	else
> > +		nandc_set_read_loc_first(chip, reg_base, 0, len, 1);
> >   
> >   	if (!nandc->props->qpic_v2) {
> >   		write_reg_dma(nandc, NAND_DEV_CMD_VLD, 1, 0);
> >   		write_reg_dma(nandc, NAND_DEV_CMD1, 1, NAND_BAM_NEXT_SGL);
> >   	}
> >   
> > -	nandc->buf_count = len;
> > +	nandc->buf_count = 512;
> >   	memset(nandc->data_buffer, 0xff, nandc->buf_count);
> >   
> >   	config_nand_single_cw_page_read(chip, false, 0);
> > --
> > 2.34.1