Messages in this thread | | | Date | Tue, 23 May 2023 12:12:39 +0300 | Subject | Re: [PATCH v4 1/5] mtd: rawnand: meson: fix command sequence for read/write | From | Arseniy Krasnov <> |
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Hello Miquel, Liang
On 22.05.2023 18:05, Miquel Raynal wrote: > Hi Arseniy, > > AVKrasnov@sberdevices.ru wrote on Mon, 15 May 2023 12:44:35 +0300: > >> This fixes read/write functionality by: >> 1) Changing NFC_CMD_RB_INT bit value. > > I guess this is a separate fix >
Ok, I'll move it to separate patch
>> 2) Adding extra NAND_CMD_STATUS command on each r/w request. > > Is this really needed? Looks like you're delaying the next op only. Is > using a delay enough? If yes, then it's probably the wrong approach. > >> 3) Adding extra idle commands during r/w request. > > Question about this below, might also be a patch on its own? > >> 4) Adding extra NAND_CMD_READ0 on each read request. >> >> Without this patch driver works unstable, for example there are a lot >> of ECC errors. > > I believe all the fixes should be Cc'ed to stable, please add in your > commits: > > Cc: stable@... >
Ack, after everything will be clear with this patch :)
>> >> Fixes: 8fae856c5350 ("mtd: rawnand: meson: add support for Amlogic NAND flash controller") >> Suggested-by: Liang Yang <liang.yang@amlogic.com> >> Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru> >> --- >> drivers/mtd/nand/raw/meson_nand.c | 30 +++++++++++++++++++++--------- >> 1 file changed, 21 insertions(+), 9 deletions(-) >> >> diff --git a/drivers/mtd/nand/raw/meson_nand.c b/drivers/mtd/nand/raw/meson_nand.c >> index 074e14225c06..2f4d8c84186b 100644 >> --- a/drivers/mtd/nand/raw/meson_nand.c >> +++ b/drivers/mtd/nand/raw/meson_nand.c >> @@ -37,7 +37,7 @@ >> #define NFC_CMD_SCRAMBLER_ENABLE BIT(19) >> #define NFC_CMD_SCRAMBLER_DISABLE 0 >> #define NFC_CMD_SHORTMODE_DISABLE 0 >> -#define NFC_CMD_RB_INT BIT(14) >> +#define NFC_CMD_RB_INT ((0xb << 10) | BIT(18) | BIT(16)) >> >> #define NFC_CMD_GET_SIZE(x) (((x) >> 22) & GENMASK(4, 0)) >> >> @@ -392,7 +392,7 @@ static void meson_nfc_set_data_oob(struct nand_chip *nand, >> } >> } >> >> -static int meson_nfc_queue_rb(struct meson_nfc *nfc, int timeout_ms) >> +static int meson_nfc_queue_rb(struct meson_nfc *nfc, int timeout_ms, int cmd_read0) >> { >> u32 cmd, cfg; >> int ret = 0; >> @@ -407,17 +407,29 @@ static int meson_nfc_queue_rb(struct meson_nfc *nfc, int timeout_ms) >> >> reinit_completion(&nfc->completion); >> >> + cmd = nfc->param.chip_select | NFC_CMD_CLE | NAND_CMD_STATUS; >> + writel(cmd, nfc->reg_base + NFC_REG_CMD); >> + meson_nfc_cmd_idle(nfc, 5); > > Why 5 and 2 below? They look like magic values. Is this totally > experimental?
@Liang, may be change it to defines ?
> >> + >> /* use the max erase time as the maximum clock for waiting R/B */ >> - cmd = NFC_CMD_RB | NFC_CMD_RB_INT >> - | nfc->param.chip_select | nfc->timing.tbers_max; > > This is not documented in the commit log, is it? > >> + cmd = NFC_CMD_RB | NFC_CMD_RB_INT | nfc->timing.tbers_max; >> writel(cmd, nfc->reg_base + NFC_REG_CMD); >> + meson_nfc_cmd_idle(nfc, 2); >> >> ret = wait_for_completion_timeout(&nfc->completion, >> msecs_to_jiffies(timeout_ms)); >> if (ret == 0) >> - ret = -1; >> + return -1; > > Please use real error codes, such as ETIMEDOUT.
Ack
> >> >> - return ret; >> + if (!cmd_read0) >> + return 0; >> + >> + cmd = nfc->param.chip_select | NFC_CMD_CLE | NAND_CMD_READ0; > > This looks really wrong, I don't get why you would need to send an > expensive READ0 command.
This logic was suggested by @Liang Yang here to fix this driver (suggested as patch): https://lore.kernel.org/linux-mtd/8537e736-44a8-d17b-7923-25d5bd406dcc@sberdevices.ru/T/#m0df09d2ab2cac98431fb268a4ce3c00dc5c7a69e @Liang, could You please give us more details?
Thanks, Arseniy
> >> + writel(cmd, nfc->reg_base + NFC_REG_CMD); >> + meson_nfc_drain_cmd(nfc); >> + meson_nfc_wait_cmd_finish(nfc, CMD_FIFO_EMPTY_TIMEOUT); >> + >> + return 0; >> } >> >> static void meson_nfc_set_user_byte(struct nand_chip *nand, u8 *oob_buf) >> @@ -623,7 +635,7 @@ static int meson_nfc_rw_cmd_prepare_and_execute(struct nand_chip *nand, >> if (in) { >> nfc->cmdfifo.rw.cmd1 = cs | NFC_CMD_CLE | NAND_CMD_READSTART; >> writel(nfc->cmdfifo.rw.cmd1, nfc->reg_base + NFC_REG_CMD); >> - meson_nfc_queue_rb(nfc, PSEC_TO_MSEC(sdr->tR_max)); >> + meson_nfc_queue_rb(nfc, PSEC_TO_MSEC(sdr->tR_max), 1); >> } else { >> meson_nfc_cmd_idle(nfc, nfc->timing.tadl); >> } >> @@ -669,7 +681,7 @@ static int meson_nfc_write_page_sub(struct nand_chip *nand, >> >> cmd = nfc->param.chip_select | NFC_CMD_CLE | NAND_CMD_PAGEPROG; >> writel(cmd, nfc->reg_base + NFC_REG_CMD); >> - meson_nfc_queue_rb(nfc, PSEC_TO_MSEC(sdr->tPROG_max)); >> + meson_nfc_queue_rb(nfc, PSEC_TO_MSEC(sdr->tPROG_max), 0); >> >> meson_nfc_dma_buffer_release(nand, data_len, info_len, DMA_TO_DEVICE); >> >> @@ -952,7 +964,7 @@ static int meson_nfc_exec_op(struct nand_chip *nand, >> break; >> >> case NAND_OP_WAITRDY_INSTR: >> - meson_nfc_queue_rb(nfc, instr->ctx.waitrdy.timeout_ms); >> + meson_nfc_queue_rb(nfc, instr->ctx.waitrdy.timeout_ms, 1); >> if (instr->delay_ns) >> meson_nfc_cmd_idle(nfc, delay_idle); >> break; > > > Thanks, > Miquèl
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