diff mbox series

[v4,1/5] mtd: rawnand: meson: fix command sequence for read/write

Message ID 20230515094440.3552094-2-AVKrasnov@sberdevices.ru (mailing list archive)
State New, archived
Headers show
Series refactoring and fix for Meson NAND | expand

Commit Message

Arseniy Krasnov May 15, 2023, 9:44 a.m. UTC
This fixes read/write functionality by:
1) Changing NFC_CMD_RB_INT bit value.
2) Adding extra NAND_CMD_STATUS command on each r/w request.
3) Adding extra idle commands during r/w request.
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.

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(-)

Comments

Miquel Raynal May 22, 2023, 3:05 p.m. UTC | #1
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

> 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@...

> 
> 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?

> +
>  	/* 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.

>  
> -	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.

> +	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
Arseniy Krasnov May 23, 2023, 9:12 a.m. UTC | #2
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
Arseniy Krasnov May 24, 2023, 9:05 a.m. UTC | #3
On 23.05.2023 12:12, Arseniy Krasnov wrote:
> 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.

Hi Miquel, small update, I found some details from @Liang's message in v1 talks from the last month:

*
After sending NAND_CMD_READ0, address, NAND_CMD_READSTART and read status(NAND_CMD_STATUS = 0x70) commands, it should send
NAND_CMD_READ0 command for exiting the read status mode from the datasheet from NAND device. but previous meson_nfc_queue_rb()
only checks the Ready/Busy pin and it doesn't send read status(NAND_CMD_STATUS = 0x70) command.
i think there is something wrong with the Ready/Busy pin(please check the hardware whether this
Ready/Busy pin is connected with SOC) or the source code. i have the board without Ready/Busy pin and prefer to use the
nfc command called RB_IO6. it sends NAND_CMD_STATUS command and checks bit6 of the status register of NAND device from the
data bus and generate IRQ if ready.
*

I guess, that sequence of commands from this patch is described in datasheet (unfortunately I don't have it and relied on the old driver).
Yesterday I tried to remove sending of NAND_CMD_STATUS from this patch, but it broke current driver - i had ECC errors, so it looks like
"shot in the dark" situation, to understand this logic.

Thanks, Arseniy

>>
>>> 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
Miquel Raynal May 26, 2023, 5:22 p.m. UTC | #4
Hi Arseniy,

avkrasnov@sberdevices.ru wrote on Wed, 24 May 2023 12:05:47 +0300:

> On 23.05.2023 12:12, Arseniy Krasnov wrote:
> > 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.  
> 
> Hi Miquel, small update, I found some details from @Liang's message in v1 talks from the last month:
> 
> *
> After sending NAND_CMD_READ0, address, NAND_CMD_READSTART and read status(NAND_CMD_STATUS = 0x70) commands, it should send
> NAND_CMD_READ0 command for exiting the read status mode from the datasheet from NAND device.

That is true.

> but previous meson_nfc_queue_rb()
> only checks the Ready/Busy pin and it doesn't send read status(NAND_CMD_STATUS = 0x70) command.
> i think there is something wrong with the Ready/Busy pin(please check the hardware whether this
> Ready/Busy pin is connected with SOC) or the source code. i have the board without Ready/Busy pin and prefer to use the
> nfc command called RB_IO6. it sends NAND_CMD_STATUS command and checks bit6 of the status register of NAND device from the
> data bus and generate IRQ if ready.
> *
> 
> I guess, that sequence of commands from this patch is described in datasheet (unfortunately I don't have it and relied on the old driver).
> Yesterday I tried to remove sending of NAND_CMD_STATUS from this patch, but it broke current driver - i had ECC errors, so it looks like
> "shot in the dark" situation, to understand this logic.

When an operation on the NAND array happens (eg. read, prog, erase),
you need to wait "some time" before accessing the internal sram or even
the chip which is "busy" until it gets "ready" again. You can probe the
ready/busy pin (that's the hardware way, fast and reliable) or you can
poll a status with NAND_CMD_STATUS. The chips are designed so they can
actually process that command while they are doing time consuming tasks
to update the host. But IIRC every byte read will return the status
until you send READ0 again, which means "I'm done with the status
read" somehow.

Please see nand_soft_waitrdy() in order to understand how this is
supposed to work. You can even use that helper (which is exported)
instead of open-coding it in your driver. See atmel or sunxi
implementations for instance.

As using the native RB pin is better, you would need to identify
whether you have one or not at probe time and then either poll the
relevant bit of your controller if there is one, or fallback to the
soft read (which should fallback on exec_op in the end).

Thanks,
Miquèl
Arseniy Krasnov May 30, 2023, 11:19 a.m. UTC | #5
On 26.05.2023 20:22, Miquel Raynal wrote:
> Hi Arseniy,
> 
> avkrasnov@sberdevices.ru wrote on Wed, 24 May 2023 12:05:47 +0300:
> 
>> On 23.05.2023 12:12, Arseniy Krasnov wrote:
>>> 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.  
>>
>> Hi Miquel, small update, I found some details from @Liang's message in v1 talks from the last month:
>>
>> *
>> After sending NAND_CMD_READ0, address, NAND_CMD_READSTART and read status(NAND_CMD_STATUS = 0x70) commands, it should send
>> NAND_CMD_READ0 command for exiting the read status mode from the datasheet from NAND device.
> 
> That is true.
> 
>> but previous meson_nfc_queue_rb()
>> only checks the Ready/Busy pin and it doesn't send read status(NAND_CMD_STATUS = 0x70) command.
>> i think there is something wrong with the Ready/Busy pin(please check the hardware whether this
>> Ready/Busy pin is connected with SOC) or the source code. i have the board without Ready/Busy pin and prefer to use the
>> nfc command called RB_IO6. it sends NAND_CMD_STATUS command and checks bit6 of the status register of NAND device from the
>> data bus and generate IRQ if ready.
>> *
>>
>> I guess, that sequence of commands from this patch is described in datasheet (unfortunately I don't have it and relied on the old driver).
>> Yesterday I tried to remove sending of NAND_CMD_STATUS from this patch, but it broke current driver - i had ECC errors, so it looks like
>> "shot in the dark" situation, to understand this logic.
> 
> When an operation on the NAND array happens (eg. read, prog, erase),
> you need to wait "some time" before accessing the internal sram or even
> the chip which is "busy" until it gets "ready" again. You can probe the
> ready/busy pin (that's the hardware way, fast and reliable) or you can
> poll a status with NAND_CMD_STATUS. The chips are designed so they can
> actually process that command while they are doing time consuming tasks
> to update the host. But IIRC every byte read will return the status
> until you send READ0 again, which means "I'm done with the status
> read" somehow.
> 
> Please see nand_soft_waitrdy() in order to understand how this is
> supposed to work. You can even use that helper (which is exported)
> instead of open-coding it in your driver. See atmel or sunxi
> implementations for instance.
> 
> As using the native RB pin is better, you would need to identify
> whether you have one or not at probe time and then either poll the
> relevant bit of your controller if there is one, or fallback to the
> soft read (which should fallback on exec_op in the end).

Thanks for this information! I'll use 'nand_soft_waitrdy()' at least, because i guess that
there is no RB pin on my device.

Thanks, Arseniy

> 
> Thanks,
> Miquèl
Miquel Raynal May 30, 2023, 1:05 p.m. UTC | #6
Hi Arseniy,

avkrasnov@sberdevices.ru wrote on Tue, 30 May 2023 14:19:08 +0300:

> On 26.05.2023 20:22, Miquel Raynal wrote:
> > Hi Arseniy,
> > 
> > avkrasnov@sberdevices.ru wrote on Wed, 24 May 2023 12:05:47 +0300:
> >   
> >> On 23.05.2023 12:12, Arseniy Krasnov wrote:  
> >>> 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.    
> >>
> >> Hi Miquel, small update, I found some details from @Liang's message in v1 talks from the last month:
> >>
> >> *
> >> After sending NAND_CMD_READ0, address, NAND_CMD_READSTART and read status(NAND_CMD_STATUS = 0x70) commands, it should send
> >> NAND_CMD_READ0 command for exiting the read status mode from the datasheet from NAND device.  
> > 
> > That is true.
> >   
> >> but previous meson_nfc_queue_rb()
> >> only checks the Ready/Busy pin and it doesn't send read status(NAND_CMD_STATUS = 0x70) command.
> >> i think there is something wrong with the Ready/Busy pin(please check the hardware whether this
> >> Ready/Busy pin is connected with SOC) or the source code. i have the board without Ready/Busy pin and prefer to use the
> >> nfc command called RB_IO6. it sends NAND_CMD_STATUS command and checks bit6 of the status register of NAND device from the
> >> data bus and generate IRQ if ready.
> >> *
> >>
> >> I guess, that sequence of commands from this patch is described in datasheet (unfortunately I don't have it and relied on the old driver).
> >> Yesterday I tried to remove sending of NAND_CMD_STATUS from this patch, but it broke current driver - i had ECC errors, so it looks like
> >> "shot in the dark" situation, to understand this logic.  
> > 
> > When an operation on the NAND array happens (eg. read, prog, erase),
> > you need to wait "some time" before accessing the internal sram or even
> > the chip which is "busy" until it gets "ready" again. You can probe the
> > ready/busy pin (that's the hardware way, fast and reliable) or you can
> > poll a status with NAND_CMD_STATUS. The chips are designed so they can
> > actually process that command while they are doing time consuming tasks
> > to update the host. But IIRC every byte read will return the status
> > until you send READ0 again, which means "I'm done with the status
> > read" somehow.
> > 
> > Please see nand_soft_waitrdy() in order to understand how this is
> > supposed to work. You can even use that helper (which is exported)
> > instead of open-coding it in your driver. See atmel or sunxi
> > implementations for instance.
> > 
> > As using the native RB pin is better, you would need to identify
> > whether you have one or not at probe time and then either poll the
> > relevant bit of your controller if there is one, or fallback to the
> > soft read (which should fallback on exec_op in the end).  
> 
> Thanks for this information! I'll use 'nand_soft_waitrdy()' at least, because i guess that
> there is no RB pin on my device.

Currently there is only support for the physical pin IIRC. This means
you cannot just drop it. You need to support both.

Thanks,
Miquèl
Arseniy Krasnov May 30, 2023, 1:35 p.m. UTC | #7
On 30.05.2023 16:05, Miquel Raynal wrote:
> Hi Arseniy,
> 
> avkrasnov@sberdevices.ru wrote on Tue, 30 May 2023 14:19:08 +0300:
> 
>> On 26.05.2023 20:22, Miquel Raynal wrote:
>>> Hi Arseniy,
>>>
>>> avkrasnov@sberdevices.ru wrote on Wed, 24 May 2023 12:05:47 +0300:
>>>   
>>>> On 23.05.2023 12:12, Arseniy Krasnov wrote:  
>>>>> 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.    
>>>>
>>>> Hi Miquel, small update, I found some details from @Liang's message in v1 talks from the last month:
>>>>
>>>> *
>>>> After sending NAND_CMD_READ0, address, NAND_CMD_READSTART and read status(NAND_CMD_STATUS = 0x70) commands, it should send
>>>> NAND_CMD_READ0 command for exiting the read status mode from the datasheet from NAND device.  
>>>
>>> That is true.
>>>   
>>>> but previous meson_nfc_queue_rb()
>>>> only checks the Ready/Busy pin and it doesn't send read status(NAND_CMD_STATUS = 0x70) command.
>>>> i think there is something wrong with the Ready/Busy pin(please check the hardware whether this
>>>> Ready/Busy pin is connected with SOC) or the source code. i have the board without Ready/Busy pin and prefer to use the
>>>> nfc command called RB_IO6. it sends NAND_CMD_STATUS command and checks bit6 of the status register of NAND device from the
>>>> data bus and generate IRQ if ready.
>>>> *
>>>>
>>>> I guess, that sequence of commands from this patch is described in datasheet (unfortunately I don't have it and relied on the old driver).
>>>> Yesterday I tried to remove sending of NAND_CMD_STATUS from this patch, but it broke current driver - i had ECC errors, so it looks like
>>>> "shot in the dark" situation, to understand this logic.  
>>>
>>> When an operation on the NAND array happens (eg. read, prog, erase),
>>> you need to wait "some time" before accessing the internal sram or even
>>> the chip which is "busy" until it gets "ready" again. You can probe the
>>> ready/busy pin (that's the hardware way, fast and reliable) or you can
>>> poll a status with NAND_CMD_STATUS. The chips are designed so they can
>>> actually process that command while they are doing time consuming tasks
>>> to update the host. But IIRC every byte read will return the status
>>> until you send READ0 again, which means "I'm done with the status
>>> read" somehow.
>>>
>>> Please see nand_soft_waitrdy() in order to understand how this is
>>> supposed to work. You can even use that helper (which is exported)
>>> instead of open-coding it in your driver. See atmel or sunxi
>>> implementations for instance.
>>>
>>> As using the native RB pin is better, you would need to identify
>>> whether you have one or not at probe time and then either poll the
>>> relevant bit of your controller if there is one, or fallback to the
>>> soft read (which should fallback on exec_op in the end).  
>>
>> Thanks for this information! I'll use 'nand_soft_waitrdy()' at least, because i guess that
>> there is no RB pin on my device.
> 
> Currently there is only support for the physical pin IIRC. This means
> you cannot just drop it. You need to support both.

Yes, i'm not going to drop RB pin support, but as I don't have device to test it(i guess), i'll add
'nand_sort_waitrdy()' anyway.

Thanks, Arseniy

> 
> Thanks,
> Miquèl

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Miquel Raynal May 30, 2023, 1:58 p.m. UTC | #8
Hi Arseniy,

avkrasnov@sberdevices.ru wrote on Tue, 30 May 2023 16:35:59 +0300:

> On 30.05.2023 16:05, Miquel Raynal wrote:
> > Hi Arseniy,
> > 
> > avkrasnov@sberdevices.ru wrote on Tue, 30 May 2023 14:19:08 +0300:
> >   
> >> On 26.05.2023 20:22, Miquel Raynal wrote:  
> >>> Hi Arseniy,
> >>>
> >>> avkrasnov@sberdevices.ru wrote on Wed, 24 May 2023 12:05:47 +0300:
> >>>     
> >>>> On 23.05.2023 12:12, Arseniy Krasnov wrote:    
> >>>>> 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.      
> >>>>
> >>>> Hi Miquel, small update, I found some details from @Liang's message in v1 talks from the last month:
> >>>>
> >>>> *
> >>>> After sending NAND_CMD_READ0, address, NAND_CMD_READSTART and read status(NAND_CMD_STATUS = 0x70) commands, it should send
> >>>> NAND_CMD_READ0 command for exiting the read status mode from the datasheet from NAND device.    
> >>>
> >>> That is true.
> >>>     
> >>>> but previous meson_nfc_queue_rb()
> >>>> only checks the Ready/Busy pin and it doesn't send read status(NAND_CMD_STATUS = 0x70) command.
> >>>> i think there is something wrong with the Ready/Busy pin(please check the hardware whether this
> >>>> Ready/Busy pin is connected with SOC) or the source code. i have the board without Ready/Busy pin and prefer to use the
> >>>> nfc command called RB_IO6. it sends NAND_CMD_STATUS command and checks bit6 of the status register of NAND device from the
> >>>> data bus and generate IRQ if ready.
> >>>> *
> >>>>
> >>>> I guess, that sequence of commands from this patch is described in datasheet (unfortunately I don't have it and relied on the old driver).
> >>>> Yesterday I tried to remove sending of NAND_CMD_STATUS from this patch, but it broke current driver - i had ECC errors, so it looks like
> >>>> "shot in the dark" situation, to understand this logic.    
> >>>
> >>> When an operation on the NAND array happens (eg. read, prog, erase),
> >>> you need to wait "some time" before accessing the internal sram or even
> >>> the chip which is "busy" until it gets "ready" again. You can probe the
> >>> ready/busy pin (that's the hardware way, fast and reliable) or you can
> >>> poll a status with NAND_CMD_STATUS. The chips are designed so they can
> >>> actually process that command while they are doing time consuming tasks
> >>> to update the host. But IIRC every byte read will return the status
> >>> until you send READ0 again, which means "I'm done with the status
> >>> read" somehow.
> >>>
> >>> Please see nand_soft_waitrdy() in order to understand how this is
> >>> supposed to work. You can even use that helper (which is exported)
> >>> instead of open-coding it in your driver. See atmel or sunxi
> >>> implementations for instance.
> >>>
> >>> As using the native RB pin is better, you would need to identify
> >>> whether you have one or not at probe time and then either poll the
> >>> relevant bit of your controller if there is one, or fallback to the
> >>> soft read (which should fallback on exec_op in the end).    
> >>
> >> Thanks for this information! I'll use 'nand_soft_waitrdy()' at least, because i guess that
> >> there is no RB pin on my device.  
> > 
> > Currently there is only support for the physical pin IIRC. This means
> > you cannot just drop it. You need to support both.  
> 
> Yes, i'm not going to drop RB pin support, but as I don't have device to test it(i guess), i'll add
> 'nand_sort_waitrdy()' anyway.

Clear. Then go for it :)

Thanks,
Miquèl
diff mbox series

Patch

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);
+
 	/* 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;
+	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;
 
-	return ret;
+	if (!cmd_read0)
+		return 0;
+
+	cmd = nfc->param.chip_select | NFC_CMD_CLE | NAND_CMD_READ0;
+	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;