old data gets overwritten in fds when i read the data after setting a new one.

RE: old data gets overwritten in fds when i read the data after setting a new one.

Hung Bui — Tue, 20 Aug 2019 10:18:34 GMT

I haven't seen this issue before. If you can provide some code that we can reproduce the issue here we can try to have a look on why this happens.

Please double check if the old record marked as dirty (header is written 0xFFFF0000).

RE: old data gets overwritten in fds when i read the data after setting a new one.

oyomj343 — Mon, 19 Aug 2019 10:40:07 GMT

So when i set the data in different records, and read anyone, the same data is getting copied everywhere.Everything seems fine to me too.I am using same file ID and different keys.I also tried for initializing descriptor and flash_record_t every time.But nothing helped. Can give some tips if you have encountered a similar issue before?

RE: old data gets overwritten in fds when i read the data after setting a new one.

Hung Bui — Wed, 07 Aug 2019 15:02:41 GMT

Yes, the record should be marked as dirty (header = 0xFFFF0000). Could you check in the flash if you see the header 0xFFFF0000 ? You can read the whole flash dump using nrfjprog.exe --readcode

If you can provide an example code (a project with source) that reproduce the issue it would be much easier for us.

Could you provide the link to the similar cases ?

Be careful when defining large virtual page. Could you try to test setting the FDS_VIRTUAL_PAGE_SIZE = FDS_PHY_PAGE_SIZE = 1024 ?

RE: old data gets overwritten in fds when i read the data after setting a new one.

oyomj343 — Wed, 07 Aug 2019 07:10:45 GMT

Yes it does create a new record with same File id and key, but i am initialising all descriptors and token every time i do a read or write.So why on read would i get the old data because it is invalidated.And also now i am using one file ID and also one page of 8kb to store all the data. I have seen this issue is also faced by other people here and i don't think they've got the solution.

RE: old data gets overwritten in fds when i read the data after setting a new one.

Hung Bui — Tue, 06 Aug 2019 13:45:29 GMT

I suspect that instead of updating the record, the code actually creating new record with same File id and key. Note that, fds allow to have multiple record having same file ID and key. Each time you use fds_record_find() with the previous token, it will try to find the next record that matches File ID and key.

Please add some debug log especially inside get_flash_data()

I would suggest instead of using

if (err_code == FDS_SUCCESS)

if (err_code == FDS_ERR_NOT_FOUND)

You use :

else {if (err_code == FDS_ERR_NOT_FOUND)

And then check if there is any other err_code.

And on each of the return code of any other API call, you need to check if it's success or not.

RE: old data gets overwritten in fds when i read the data after setting a new one.

oyomj343 — Tue, 06 Aug 2019 12:31:04 GMT

I tried your example and it worked properly.As you have seen my code, I declared an array of record & file id to save different records at different pages.The data that i am saving is -

1.Array of structs[100](pg 0-4).

2.One separate struct(pg 5)

So whenever i get and set the data, i provide the index also for record,file ID.If there is no record, it creates a new one.When i updates any file, it invalidates the old one.But when i reads it, i gets one step back and gives the old data.If i keep reading, it goes one step back everytime.

RE: old data gets overwritten in fds when i read the data after setting a new one.

Hung Bui — Tue, 06 Aug 2019 08:39:07 GMT

Please post your full source on how you test it. It looks fine in the posted code.

Have you tried testing using our flash_fds example in the nRF5 SDK ?

RE: old data gets overwritten in fds when i read the data after setting a new one.

oyomj343 — Tue, 06 Aug 2019 06:42:07 GMT

i am testing it on nrf52832. So when i do the update(set_flash_data), it invalidates the old data, but then when i read it's the old one always.Can you pls tell how is this happening in my code?

RE: old data gets overwritten in fds when i read the data after setting a new one.

Hung Bui — Fri, 02 Aug 2019 15:11:54 GMT

Hi,

Could you explain a little bit more how you test this ?

You need to store 7kB ?

We have a simple example here that you can try. If you can modify the example to show the issue you have, it would be nice.