Bug Report: I2C TWI driver always returns -EIO due to NRFX_SUCCESS comparison mismatch

Question

Affecte d SDK : n RF Connect SDK v 3.2.0 (Zephyr v 4. 2.9 9) 
 File : z ephyr/drivers/i2c /i2c_nrf x_twi.c 
 Description 
 The I2C TWI driver always returns - EIO for every transfer, even when the transfer completes successfully. This is cause d by a m ismatch between the value set in the event handler and the value checke d in the transfer function. 
 Root Cause 
 In the event handler ( event _handler ) , on successful completion : 
 case NRFX_TWI_EVT_DONE:
 dev_data->res = 0; // Sets res to 0
 break; 
 In i 2c_nrfx_ twi_transfer () , the success check is: 
 if (data->res != NRFX_SUCCESS) {
 ret = -EIO;
 break;
} 
 However , NRFX_SUCCESS is defined in nrfx_errors. h as: 
 #define NRFX_ERROR_BASE_NUM 0x0BAD0000
NRFX_SUCCESS = (NRFX_ERROR_BASE_NUM + 0), // = 0x0BAD0000 
 So the comparison 0 != 0x0BAD 0000 is always true, causing every I2C transfer to fail with -EIO . 
 Impact 
 
 All I2C devices using the nordic , n rf-twi compatible driver fail to communicate

This affects any boar d using TW I (not TWIM) for I2C 
 
 Proposed Fix 
 Change line 11 2 in i2c_n rfx_twi.c from: 
 dev_data->res = 0; 
 to: 
 dev_data->res = NRFX_SUCCESS; 
 Alternatively/Additionally, NRFX_SUCCESS should be defined as 0. 
 How to Reproduce 
 
 Use n RF Connect SDK v3. 2. 0

Configure I2C with compatible = "nordic,nrf-twi"

Attempt any I2C transfer

Observe that all transfers return -EIO (- 5) 
 
 Environment 
 
 n RF Connect SDK : v3.2.0

Zephyr: v4. 2.9 9

Target : n RF5284 0