[PATCH linux dev-4.7] arm: configs: aspeed: Disable CONFIG_MTD_SPI_NOR_USE_4K_SECTORS

[Cédric Le Goater]

On 05/15/2017 02:41 AM, Adriana Kobylak wrote:
> 
>> On May 13, 2017, at 3:49 PM, Cédric Le Goater <clg at kaod.org> wrote:
>>
>> On 05/11/2017 02:12 PM, Joel Stanley wrote:
>>> On Thu, May 11, 2017 at 7:31 AM, Adriana Kobylak
>>> <anoo at linux.vnet.ibm.com> wrote:
>>>> Milton stopped by and mentioned that you had tried to modify the 4K erase
>>>> sector previously for a perhaps bmc chip and saw some flash corruption when
>>>> moving to an image that changed it?
>>>>
>>>> Just wanted to add that this change only changes the pnor setting and I
>>>> didn’t see any issues powering on a system after updating the BMC with an
>>>> image with this change. Then I updated the pnor with an image that had the
>>>> mbox enabled. Also checked with AndrewJ and the hostboot team and there’s no
>>>> hard-coded assumptions in their side about the erase size.
>>>>
>>>> With all this info let me know if you have any thoughts or concerns.
>>>
>>> I recall issues relating to this option. I didn't record what they were 
>>> though.
>>
>> We tried to activate 4K erase on some chips, which supported it, 
>> and that the OpenPOWER systems use. That was because the PNOR 
>> sections were not aligned with the erase size and that caused 
>> some issues in pflash. But it breaks the compatibility with 
>> previously created jffs2 filesystems. jffs2 stores the erase 
>> size. So we stepped back.
>>
>>> Cedric, can you remind me what the issues are with the 4K kconfig option?
>>
>> CONFIG_MTD_SPI_NOR_USE_4K_SECTORS enables the 4K erase commands, 
>> and without it, the driver will use the sector erase command, most
>> likely 64K. I suppose we could have the same problem as described 
>> above, as it can change the default erase size of a chip. to be
>> checked.
>>
> Thanks Cedric for the info. It appears there are no issues when 
> disabling the 4K sectors for the pnor chip (yes, the erase size 
> is then 64K), probably because the pnor is not formatted with 
> a jffs2 filesystem. We might need to clear the pnor chip anyways
> to be able to format it as a UBI volume. So would you say we’re 
> ok with this patch?

Well, what if the BMC is using a flash module with a 4K erase size ? 

C.