On Thu, Feb 9, 2017 at 4:23 PM, Charles Manning <
cdhmanning@gmail.com>
wrote:
> Hi Hunter
>
> On Fri, Feb 10, 2017 at 8:57 AM, Hunter Somerville <hsomervi5790@gmail.com
> > wrote:
>
>> On Tue, Feb 7, 2017 at 3:44 PM, Charles Manning <cdhmanning@gmail.com>
>> wrote:
>>
>>> On Tue, Feb 7, 2017 at 5:19 AM, Hunter Somerville <
>>> hsomervi5790@gmail.com> wrote:
>>>
>>>> Hello,
>>>>
>>>> We are encountering an issue where we will usually lose an entire
>>>> partition of data if the flash device loses power during a write operation.
>>>> When we bring the system back up and remount, all files/directories appear
>>>> as long strings of questionmarks with incorrect filenames and such, and we
>>>> end up having to flash erase the partition to recover. This only happens on
>>>> the device with fairly large pages (4MB Erase blocks, 32KB pages, 1KB OOB),
>>>> and does not occur on the more typical device in the same system which uses
>>>> 4KB pages.
>>>>
>>>
>>> What kind of flash are you using? What part number?
>>>
>>
>> The hardware is proprietary, and not designed by us. What I can tell you
>> is that we interface with an FPGA - not the flash chips directly. The FPGA
>> performs the writes.
>>
>
> Surely the flash parts are off the shelf.
>
I'm getting permission on this. They're Samsung parts.
We've discovered that mounting the partition as read-only after powerloss
demonstrates that the data is all present and correct, aside from the file
which was actively being written. I can read back any of the files and
verify their contents. If at any point I mount this partition as read-write
after the powerloss, yaffs appears to mark all blocks as unused and then
proceeds to garbage collect every block. My files all slowly disappear.
yaffs: Collecting block 3, in use 1, shrink 0, whole_block 0
yaffs: Collecting block 3 that has no chunks in use
yaffs: yaffs_block_became_dirty block 3 state 8
yaffs: yaffs_tags_marshall_read chunk 256 data ef1f0000 tags ef6f5cd8
yaffs: packed tags obj -1 chunk -1 byte -1 seq -1
yaffs: ext.tags eccres 1 blkbad 0 chused 0 obj 0 chunk0 byte 0 del 0 ser 0
seq 0
yaffs: yaffs_tags_marshall_read chunk 257 data ef1f0000 tags ef6f5cd8
yaffs: packed tags obj -1 chunk -1 byte -1 seq -1
yaffs: ext.tags eccres 1 blkbad 0 chused 0 obj 0 chunk0 byte 0 del 0 ser 0
seq 0
.......
yaffs: yaffs_tags_marshall_read chunk 382 data ef1f0000 tags ef6f5cd8
yaffs: packed tags obj -1 chunk -1 byte -1 seq -1
yaffs: ext.tags eccres 1 blkbad 0 chused 0 obj 0 chunk0 byte 0 del 0 ser 0
seq 0
yaffs: yaffs_tags_marshall_read chunk 383 data ef1f0000 tags ef6f5cd8
yaffs: packed tags obj -1 chunk -1 byte -1 seq -1
yaffs: ext.tags eccres 1 blkbad 0 chused 0 obj 0 chunk0 byte 0 del 0 ser 0
seq 0
yaffs: Erased block 3
I can't yet figure out why it's marking these blocks as unused when there
are clearly files present. Any help on this matter would be greatly
appreciated.
Thanks,
Hunter
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