Re: [PATCH V3] mtd: rawnand: qcom: update last code word register

From: Manivannan Sadhasivam
Date: Thu Jan 28 2021 - 02:54:58 EST

On Sun, Jan 10, 2021 at 09:31:45AM +0530, Md Sadre Alam wrote:
> From QPIC version 2.0 onwards new register got added to
> read last codeword. This change will update the same.
>
> For first three code word READ_LOCATION_n register will be
> use.For last code word READ_LOCATION_LAST_CW_n register will be
> use.
>
> Signed-off-by: Md Sadre Alam <mdalam@xxxxxxxxxxxxxx>

I gave this patch a try on SDX55 board but not able to resolve an issue and
I think it is related to reading the last code word which this patch is trying
to address. For my patch on supporting QPIC v2 IP, I tested with SDX55-MTP board
and I never hit any issue. But on my new dev board (Telit FN980), there seems to
be an issue while populating the partitions and tracing down that bug lands me
in copy_last_cw() function.

The issue only happens while creating the 3rd partition on Telit board whose
size differs when compared with MTP. The board just reboots into QDL mode
whenever it tries to read the last code word.

Below is the snippet of partition layout:

Telit partitions:

[ 1.082015] 0: sbl offs=0x00000000 size=0x0000000a attr:0x000000ff
[ 1.082702] 1: mibib offs=0x0000000a size=0x0000000a attr:0x000000ff
[ 1.083488] 2: ico offs=0x00000014 size=0x00000014 attr:0x000000ff
[ 1.084572] 3: efs2 offs=0x00000028 size=0x0000002c attr:0x000000ff
[ 1.085316] 4: tz offs=0x00000054 size=0x00000007 attr:0x000000ff
[ 1.086089] 5: tz_devcfg offs=0x0000005b size=0x00000004 attr:0x000000ff
....

MTP partitions:

[ 1.573871] 0: sbl offs=0x00000000 size=0x0000000a attr:0x000000ff
[ 1.581139] 1: mibib offs=0x0000000a size=0x0000000a attr:0x000000ff
[ 1.587362] 2: efs2 offs=0x00000014 size=0x0000002c attr:0x000000ff
[ 1.593853] 3: tz offs=0x00000040 size=0x00000007 attr:0x000000ff
[ 1.599860] 4: tz_devcfg offs=0x00000047 size=0x00000004 attr:0x000000ff
...

So until I figure this out, please keep this patch on hold!

Thanks,
Mani

> ---
> [V3]
> * Added else condition for last code word in update_rw_regs().
> drivers/mtd/nand/raw/qcom_nandc.c | 84 ++++++++++++++++++++++++++++++++-------
> 1 file changed, 70 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c
> index 667e4bf..50ff6e3 100644
> --- a/drivers/mtd/nand/raw/qcom_nandc.c
> +++ b/drivers/mtd/nand/raw/qcom_nandc.c
> @@ -48,6 +48,10 @@
> #define NAND_READ_LOCATION_1 0xf24
> #define NAND_READ_LOCATION_2 0xf28
> #define NAND_READ_LOCATION_3 0xf2c
> +#define NAND_READ_LOCATION_LAST_CW_0 0xf40
> +#define NAND_READ_LOCATION_LAST_CW_1 0xf44
> +#define NAND_READ_LOCATION_LAST_CW_2 0xf48
> +#define NAND_READ_LOCATION_LAST_CW_3 0xf4c
>
> /* dummy register offsets, used by write_reg_dma */
> #define NAND_DEV_CMD1_RESTORE 0xdead
> @@ -187,6 +191,12 @@ nandc_set_reg(nandc, NAND_READ_LOCATION_##reg, \
> ((size) << READ_LOCATION_SIZE) | \
> ((is_last) << READ_LOCATION_LAST))
>
> +#define nandc_set_read_loc_last(nandc, reg, offset, size, is_last) \
> +nandc_set_reg(nandc, NAND_READ_LOCATION_LAST_CW_##reg, \
> + ((offset) << READ_LOCATION_OFFSET) | \
> + ((size) << READ_LOCATION_SIZE) | \
> + ((is_last) << READ_LOCATION_LAST))
> +
> /*
> * Returns the actual register address for all NAND_DEV_ registers
> * (i.e. NAND_DEV_CMD0, NAND_DEV_CMD1, NAND_DEV_CMD2 and NAND_DEV_CMD_VLD)
> @@ -316,6 +326,10 @@ struct nandc_regs {
> __le32 read_location1;
> __le32 read_location2;
> __le32 read_location3;
> + __le32 read_location_last0;
> + __le32 read_location_last1;
> + __le32 read_location_last2;
> + __le32 read_location_last3;
>
> __le32 erased_cw_detect_cfg_clr;
> __le32 erased_cw_detect_cfg_set;
> @@ -644,6 +658,14 @@ static __le32 *offset_to_nandc_reg(struct nandc_regs *regs, int offset)
> return &regs->read_location2;
> case NAND_READ_LOCATION_3:
> return &regs->read_location3;
> + case NAND_READ_LOCATION_LAST_CW_0:
> + return &regs->read_location_last0;
> + case NAND_READ_LOCATION_LAST_CW_1:
> + return &regs->read_location_last1;
> + case NAND_READ_LOCATION_LAST_CW_2:
> + return &regs->read_location_last2;
> + case NAND_READ_LOCATION_LAST_CW_3:
> + return &regs->read_location_last3;
> default:
> return NULL;
> }
> @@ -719,9 +741,14 @@ static void update_rw_regs(struct qcom_nand_host *host, int num_cw, bool read)
> nandc_set_reg(nandc, NAND_READ_STATUS, host->clrreadstatus);
> nandc_set_reg(nandc, NAND_EXEC_CMD, 1);
>
> - if (read)
> - nandc_set_read_loc(nandc, 0, 0, host->use_ecc ?
> - host->cw_data : host->cw_size, 1);
> + if (read) {
> + if (nandc->props->qpic_v2)
> + nandc_set_read_loc_last(nandc, 0, 0, host->use_ecc ?
> + host->cw_data : host->cw_size, 1);
> + else
> + nandc_set_read_loc(nandc, 0, 0, host->use_ecc ?
> + host->cw_data : host->cw_size, 1);
> + }
> }
>
> /*
> @@ -1096,9 +1123,13 @@ static void config_nand_page_read(struct qcom_nand_controller *nandc)
> static void
> config_nand_cw_read(struct qcom_nand_controller *nandc, bool use_ecc)
> {
> - if (nandc->props->is_bam)
> + if (nandc->props->is_bam) {
> + if (nandc->props->qpic_v2)
> + write_reg_dma(nandc, NAND_READ_LOCATION_LAST_CW_0,
> + 1, NAND_BAM_NEXT_SGL);
> write_reg_dma(nandc, NAND_READ_LOCATION_0, 4,
> NAND_BAM_NEXT_SGL);
> + }
>
> write_reg_dma(nandc, NAND_FLASH_CMD, 1, NAND_BAM_NEXT_SGL);
> write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
> @@ -1633,16 +1664,28 @@ qcom_nandc_read_cw_raw(struct mtd_info *mtd, struct nand_chip *chip,
> }
>
> if (nandc->props->is_bam) {
> - nandc_set_read_loc(nandc, 0, read_loc, data_size1, 0);
> + if (nandc->props->qpic_v2 && cw == (ecc->steps - 1))
> + nandc_set_read_loc_last(nandc, 0, read_loc, data_size1, 0);
> + else
> + nandc_set_read_loc(nandc, 0, read_loc, data_size1, 0);
> read_loc += data_size1;
>
> - nandc_set_read_loc(nandc, 1, read_loc, oob_size1, 0);
> + if (nandc->props->qpic_v2 && cw == (ecc->steps - 1))
> + nandc_set_read_loc_last(nandc, 1, read_loc, oob_size1, 0);
> + else
> + nandc_set_read_loc(nandc, 1, read_loc, oob_size1, 0);
> read_loc += oob_size1;
>
> - nandc_set_read_loc(nandc, 2, read_loc, data_size2, 0);
> + if (nandc->props->qpic_v2 && cw == (ecc->steps - 1))
> + nandc_set_read_loc_last(nandc, 2, read_loc, data_size2, 0);
> + else
> + nandc_set_read_loc(nandc, 2, read_loc, data_size2, 0);
> read_loc += data_size2;
>
> - nandc_set_read_loc(nandc, 3, read_loc, oob_size2, 1);
> + if (nandc->props->qpic_v2 && cw == (ecc->steps - 1))
> + nandc_set_read_loc_last(nandc, 3, read_loc, oob_size2, 0);
> + else
> + nandc_set_read_loc(nandc, 3, read_loc, oob_size2, 1);
> }
>
> config_nand_cw_read(nandc, false);
> @@ -1873,14 +1916,27 @@ static int read_page_ecc(struct qcom_nand_host *host, u8 *data_buf,
>
> if (nandc->props->is_bam) {
> if (data_buf && oob_buf) {
> - nandc_set_read_loc(nandc, 0, 0, data_size, 0);
> - nandc_set_read_loc(nandc, 1, data_size,
> - oob_size, 1);
> + if (nandc->props->qpic_v2 && i == (ecc->steps - 1)) {
> + nandc_set_read_loc_last(nandc, 0, 0, data_size, 0);
> + nandc_set_read_loc_last(nandc, 1, data_size,
> + oob_size, 1);
> + } else {
> + nandc_set_read_loc(nandc, 0, 0, data_size, 0);
> + nandc_set_read_loc(nandc, 1, data_size,
> + oob_size, 1);
> + }
> } else if (data_buf) {
> - nandc_set_read_loc(nandc, 0, 0, data_size, 1);
> + if (nandc->props->qpic_v2 && i == (ecc->steps - 1))
> + nandc_set_read_loc_last(nandc, 0, 0, data_size, 1);
> + else
> + nandc_set_read_loc(nandc, 0, 0, data_size, 1);
> } else {
> - nandc_set_read_loc(nandc, 0, data_size,
> - oob_size, 1);
> + if (nandc->props->qpic_v2 && i == (ecc->steps - 1))
> + nandc_set_read_loc_last(nandc, 0, data_size,
> + oob_size, 1);
> + else
> + nandc_set_read_loc(nandc, 0, data_size,
> + oob_size, 1);
> }
> }
>
> --
> 2.7.4
>