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

[Adriana Kobylak]

> On May 16, 2017, at 1:01 AM, Cédric Le Goater <clg at kaod.org> wrote:
> 
> 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 ? 

All the mtd devices except PNOR in the P8 and P9 systems running openbmc have already an erase size of 64K.

Ex witherspoon:
root at witherspoon:~# cat /proc/mtd 
dev:    size   erasesize  name
mtd0: 02000000 00010000 "bmc"
mtd1: 00060000 00010000 "u-boot"
mtd2: 00020000 00010000 "u-boot-env"
mtd3: 00440000 00010000 "kernel"
mtd4: 01740000 00010000 "rofs"
mtd5: 00400000 00010000 "rwfs"
mtd6: 02000000 00010000 "alt"
mtd7: 08000000 00001000 “pnor”

Ex barreleye:
root at barreleye:~# cat /proc/mtd 
dev:    size   erasesize  name
mtd0: 02000000 00010000 "bmc"
mtd1: 00060000 00010000 "u-boot"
mtd2: 00020000 00010000 "u-boot-env"
mtd3: 00440000 00010000 "kernel"
mtd4: 01740000 00010000 "rofs"
mtd5: 00400000 00010000 "rwfs"
mtd6: 04000000 00001000 "pnor"

> 
> C.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.ozlabs.org/pipermail/openbmc/attachments/20170516/94379d35/attachment-0001.html>