File Delete in littleFS results in -22 error

[BenKrug]

So I have a device on a custom PCB with an nrf52832 and a mx25r1635f, with which I've had quite some trouble already(  File write gives -5 after file size reaches cache size  ). In most of the devices it's working correctly and was working up until a couple hours ago, but now any operation with the Flash takes over 14 SECONDS!, that's ludicrous to me, I tried to delete the files and clear the flash, giving the -22 error, I'm very lost at this point, since I can't delete the files individually, can't clear the flash area. Does anyone know what could be the case happening here? Config information can be found on the ticket I linked.

[droidecahedron]

The page you linked is a dead URL.

Here's some background info I've experienced:

When using LittleFS, operations begin to take a long while as the file sizes get bigger. 14 seconds can sometimes happen depending on the flash youre using and how big the littlefs file is.

Check this out:

(x axis - write size, y axis - ratio between average fs write speed vs average raw write speed)

Try formatting and re-mounting the file system. It's odd that it's not letting you delete, but it could be due to a timeout.

I've run into that and had to change the timeout for the flash interactions.

[BenKrug]

Hi, fixed the link, due to the error mentioned on the linked ticket, the file is only 127 bytes long, so 14 seconds doesn't make sense

[droidecahedron]

127 bytes definitely doesnt make sense for 14 seconds.

Does this behavior occur between every single "fs reset" like format/unmount/mount?

[BenKrug]

Yes it happens constantly now on a specific hardware, on every reset. On the other PCBs it doesn't happen, it's only on that one specific board.

[droidecahedron]

If it only happens on one specific board you have and not others, my instinct would be to assume something is up with that board.

could you clarify?

[BenKrug]

Yeah, I also think it might be a problem with the board, what's weird to me is it was working just fine up until a little while ago. And I really need to fix this issue with the board, since I have to get 200 boards ready for production and there were only 200 boards fabricated in China(yeah, I know it's a really bad idea, but it wasn't me who decided the quantity). I just thought something in the firmware could be the culprit.

[Jørgen Holmefjord]

Hi,

Can you do some more debugging to see what happens in the 14 seconds? Is the application stuck waiting for some event, etc? Have you scoped the SPI lines to see how long the actual transfer/commands take, and if these are transmitted as expected?

Best regards,
Jørgen

[BenKrug]

Hi, currently I can't probe these aspects as I have other pressing problems to solve, but once I get the time I'll be sure to do that.