[PATCH] mtd: spi-nor: Recover from Spansion/Cypress errors

[Alexander Sverdlin]

Hi!

On 13/06/17 22:16, Cyrille Pitchen wrote:
> this patch looks good to me.
> If Marek is fine with as well, I can apply it.
> 
> Otherwise, if a new version is needed, then please note that this patch
> doesn't apply directly on the spi-nor/next branch of the l2-mtd tree.
> 
> It can be fixed quite easily, I show you below the faulty chunk.

Thanks! I'll rebase to spi-nor/next in case re-spin will be necessary.

> Le 12/06/2017 à 17:01, Alexander Sverdlin a écrit :
>> S25FL{128|256|512}S datasheets say:
>> "When P_ERR or E_ERR bits are set to one, the WIP bit will remain set to
>> one indicating the device remains busy and unable to receive new operation
>> commands. A Clear Status Register (CLSR) command must be received to return
>> the device to standby mode."
>>
>> Current spi-nor code works until first error occurs, but write/erase errors
>> are not just rare hardware failures, they also occur if user tries to flash
>> write-protected areas. After such attempt no SPI command can be executed
>> any more and even read fails. This patch adds support for P_ERR and E_ERR
>> bits in Status Register 1 (so that operation fails immediately and not
>> after a long timeout) and proper recovery from the error condition.
>>
>> Tested on Spansion S25FS128S, which is supported by S25FL129P entry.
>>
>> Signed-off-by: Alexander Sverdlin <alexander.sverdlin at nokia.com>
>> ---
>>  drivers/mtd/spi-nor/spi-nor.c | 29 +++++++++++++++++++++--------
>>  include/linux/mtd/spi-nor.h   |  5 +++++
>>  2 files changed, 26 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
>> index dea8c9c..efb3519 100644
> [...]
>> @@ -1641,6 +1652,8 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode)
>>  		nor->flags |= SNOR_F_HAS_SR_TB;
>>  	if (info->flags & NO_CHIP_ERASE)
>>  		nor->flags |= SNOR_F_NO_OP_CHIP_ERASE;
>> +	if (info->flags & USE_CLSR)
>> +		nor->flags |= SNOR_F_USE_CLSR;
>>  
>>  #ifdef CONFIG_MTD_SPI_NOR_USE_4K_SECTORS
>>  	/* prefer "small sector" erase if possible */
> The 2 last lines of this chunk have changed, now they should be:
> +	if (info->flags & SPI_NOR_NO_ERASE)
> +		mtd->flags |= MTD_NO_ERASE;

-- 
Best regards,
Alexander Sverdlin.