Concurrent usage of NV and settings on the same partition

[DominikRekawek]

Hi,

Is it safe to use NVS and Settings on the same partition at the same time (the same application, BLE is running, NVS can be called concurrently to eg. pairing process)?

Assumptions:

• Code that is using NVS performs nvs_init() on the settings_storage partition
• Code that is using NVS is not exceeding  NVS_NAMECNT_ID  id

Dominik,

[Simon]

Hello Dominik,

I'll take a look at this today/Monday

Best regards,

Simon

[DominikRekawek]

Hi,

Sorry for long idle time but we had to consider other options that could replace NVS. The discussion ends up with a statement that NV + Settings is what we really need to have in product. Please find attached reproduction app.


Application flow is:
- Initialize NV, do some read/write

- Pair

-Read/Write

-Reboot

After reboot there is no bounded device found.

I wonder if NVS+Settings shopuld work using theirs own APIs or if I should provide custorm load/save implementation for settings that will use NVS that is initialized in sope of my application.

Dominik,

settings_nvs_ble.7z

[Simon]

Hello Dominik,

I'll test your sample next week

Best regards,

Simon

[Simon]

I talked to a developer, and one thing we forgot to inform you about, is that you need to use the same nvs_fs struct as the settings backend.

Please apply this patch to Zephyr v3.0.99-ncs1 (part of NCS v2.0.0):

diff --git a/subsys/settings/src/settings_nvs.c b/subsys/settings/src/settings_nvs.c
index 24e7a9e79e..85c5da8f0c 100644
--- a/subsys/settings/src/settings_nvs.c
+++ b/subsys/settings/src/settings_nvs.c
@@ -273,9 +273,14 @@ int settings_nvs_backend_init(struct settings_nvs *cf)
 	return 0;
 }
 
+static struct settings_nvs default_settings_nvs;
+
+struct nvs_fs* get_nvs_fs_structure(void){
+	return &default_settings_nvs.cf_nvs;
+}
+
 int settings_backend_init(void)
 {
-	static struct settings_nvs default_settings_nvs;
 	int rc;
 	uint16_t cnt = 0;
 	size_t nvs_sector_size, nvs_size = 0;

I simply added an API to get the nvs_fs struct

Then test the following sample:

settings_nvs_ble_v2.zip

I modified your sample to use the API to get the nvs_fs settings struct and use that for your nvs calls.

[Simon]

My fix does the job, but is probably not an optimal solution. I created a Zephyr issue regarding this which you can follow here: https://github.com/zephyrproject-rtos/zephyr/issues/48328 

Best regards,

Simon