NVM process on SPI bus seems to be interfered with during BLE_GATTS_EVT_WRITE event

[ccrider]

During an execution of a  winbond w25q64jv command (any command) during a BLE_GATTS_EVT_WRITE event the SPI bus goes inactive after the command is sent:

There is apparently no issue if I do any NVM operation outside a BLE_GATTS_EVT_WRITE event. 

[Edvin]

Hello,

ccrider said:

I am not waiting for a callback.

That sounds like a reasonable workaround. However, I am still not sure what you are doing in your snippets. 

ccrider said:

I added a call to the NVM function (Test_write_and_read_of_NVM();) that is known to work was added here:

Do you refer to the Test_write_and_read_of_NVM()?

Is Test_write_and_read_of_NVM() the same as in your previous snippet?

ccrider said:

When I pause execution is shows it is running here:

Where? Is it stuck here?

while (!spi_xfer_done)
{
    __WFE();
}

ccrider said:

I am not waiting for a callback. 

So where is "spi_xfer_done" being changed?

My suspection is that you are waiting for a callback to set spi_xfer_done to true, but this callback will not be executed because you are waiting in another callback with the same or higher priority. 

So there are two workarounds for this:

1: In your on_Command_write() callback, just set a flag or something, and then handle the SPI transfer from the main context later.

2: Increase the spi IRQ priority. You can set it to 2 or 3, as described here. The way you set it is in sdk_config.h. Search for SPI_IRQ_PRIORITY and NRFX_SPI_DEFAULT_CONFIG_IRQ_PRIORITY and set them both to e.g. 3.

Best regards,

Edvin