I2c warning when gpio is toggled

Hi All,

I am using the wp7608 with mangOH evaluation board. When I toggle the gpio40 from linux, i get the following warnings.

[ 610.795386] i2c-msm-v2 78b8000.i2c: NACK: slave not responding, ensure its powered: msgs(n:1 cur:0 tx) bc(rx:0 tx:18) mode:FIFO slv_addr:0x3a MSTR_STS:0x0c1300c8 OPER:0x00000090

Though the gpio40 state changes to 1.8 volts for high and 0 volts for low, but what is the warning from the system trying to indicate ?

Below is the current state of the gpio’s
+WIOCFG: 2,16,0,0,1,0,0
+WIOCFG: 6,0,0,0,1,0,0
+WIOCFG: 7,16,0,0,1,0,0
+WIOCFG: 8,16,0,0,1,0,0
+WIOCFG: 13,16,0,0,1,0,0
+WIOCFG: 21,16,0,0,1,0,0
+WIOCFG: 22,16,0,0,1,0,0
+WIOCFG: 23,16,0,0,1,0,0
+WIOCFG: 24,16,0,0,1,0,0
+WIOCFG: 25,16,0,0,1,0,0
+WIOCFG: 28,16,0,0,1,0,0
+WIOCFG: 29,16,0,0,1,0,0
+WIOCFG: 30,16,0,0,1,0,0
+WIOCFG: 31,16,0,0,1,0,0
+WIOCFG: 32,16,0,0,1,0,0
+WIOCFG: 33,16,0,0,1,0,0
+WIOCFG: 35,16,0,0,1,0,0
+WIOCFG: 42,16,0,0,1,0,0



normally i will just ignore those warning message as far as I can control the GPIO.

I agree . But what is that warning messages trying to say to the user ? Especially the slave address 0x3a. Anything that I can infer from that message ?