Re: [PATCH v5 07/23] mtd: nand: denali: do not propagate NAND_STATUS_FAIL to waitfunc()

Masahiro Yamada
2017-06-08T06:11:49Z

Hi Boris,

2017-06-07 22:33 GMT+09:00 Boris Brezillon <boris.brezillon@free-electrons.com>:
> On Wed, 7 Jun 2017 20:52:16 +0900
> Masahiro Yamada <yamada.masahiro@socionext.com> wrote:
>
>> Currently, the error handling of denali_write_page(_raw) is a bit
>> complicated. If the program command fails, NAND_STATUS_FAIL is set
>> to the driver internal denali->status, then read out later by
>> denali_waitfunc().
>>
>> We can avoid it by exploiting the nand_write_page() implementation.
>> If chip->ecc.write_page(_raw) returns negative code (i.e. -EIO), it
>> errors out immediately. This gives the same result as returning
>> NAND_STATUS_FAIL from chip->waitfunc. In either way, -EIO is
>> returned to the upper MTD layer.
>
> Actually, this is how it's supposed to work now (when they set
> the NAND_ECC_CUSTOM_PAGE_ACCESS flag, drivers are expected to wait for
> the program operation to finish and return -EIO if it failed), so you're
> all good ;-).
>
>>
>> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
>> ---
>>
>> Changes in v5: None
>> Changes in v4: None
>> Changes in v3: None
>> Changes in v2:
>> - Newly added
>>
>> drivers/mtd/nand/denali.c | 12 ++++--------
>> drivers/mtd/nand/denali.h | 1 -
>> 2 files changed, 4 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
>> index 1897fe238290..22acfc34b546 100644
>> --- a/drivers/mtd/nand/denali.c
>> +++ b/drivers/mtd/nand/denali.c
>> @@ -1005,6 +1005,7 @@ static int write_page(struct mtd_info *mtd, struct nand_chip *chip,
>> size_t size = mtd->writesize + mtd->oobsize;
>> uint32_t irq_status;
>> uint32_t irq_mask = INTR__DMA_CMD_COMP | INTR__PROGRAM_FAIL;
>
> As mentioned in my previous patch, I think you should wait for
> INTR__PROGRAM_COMP | INTR__PROGRAM_FAIL here.

No.
It is intentional to use INTR__DMA_CMD_COMP
instead of INTR__PROGRAM_COMP here.

This is very strange of this IP,
INTR__PROGRAM_COMP is never set when DMA mode is being used.
(INTR__DMA_CMD_COMP is set instead.)

As far as I tested this IP,
INTR__PROGRAM_COMP is set only when data are written by PIO mode.

I introduced PIO transfer in
http://patchwork.ozlabs.org/patch/772398/

I used INTR__PROGRAM_COMP in denali_pio_write().

>> + int ret = 0;
>>
>> denali->page = page;
>>
>> @@ -1038,13 +1039,13 @@ static int write_page(struct mtd_info *mtd, struct nand_chip *chip,
>> if (irq_status == 0) {
>> dev_err(denali->dev, "timeout on write_page (type = %d)\n",
>> raw_xfer);
>> - denali->status = NAND_STATUS_FAIL;
>> + ret = -EIO;
>> }
>
> if (irq_status & INTR__PROGRAM_FAIL) {
> dev_err(denali->dev, "page program failed (type = %d)\n",
> raw_xfer);
> ret = -EIO;
> }

This will be fixed anyway by
http://patchwork.ozlabs.org/patch/772414/

I do not want to include unrelated change.

--
Best Regards
Masahiro Yamada