MPU9250 (SPI) and AK8963 reset

Hi all,
when i try to reset (stop) device :

	writeMPU9XReg(MPU9X_I2C_MST_DELAY_CTRL, 0); // Slave 0 accessed automatic

writeMPU9XReg(MPU9X_I2C_SLV4_CTRL, 0); // Slave 0 frequency read

mdelay(100);

writeSlaveReg(AK8963_ADDRESS, AK8963_CNTL1, 0); // Power down

mdelay(100);

writeMPU9XReg(MPU9X_USER_CTRL,  MPU9X_I2C_MST_RESET); //Reset Master

mdelay(100);

// Reset Device

writeMPU9XReg(MPU9X_PWR_MGMT_1, MPU9X_PWR_DEV_RESET);

i can't read AK8963 ... and I2C_MST_STATUS = 0x03
it works only when i power down mpu-9250.

any helps!