spi while loop stuck

[Robert]

Hello ! I am trying to read WHO_AM_I register from a LSM9DS1 IMU. I have spi_update_imu_data() as my callback for when the spi transfer completes and inside it I make spi_xfer_done=true. Inside a timer_timeout_handler, I first call nrf_drv_spi_transfer(&spi, m_tx_buf, m_length, m_rx_buf, m_length) where m_tx_buf[2] = {0x80 | WHO_AM_I, 0x00} and m_rx_buf[3] = {0x00, 0x00, 0x00}. The board gets stuck when after the transfer I do while(!spi_xfer_done){spi_xfer_done = false;}.

Can somebody please help me on this issue ? I am using nrf51822 with s130 with the softdevice enabled.

[Ole Bauck]

is the while(!spi_xfer_done){spi_xfer_done = false;} inside the timeout handler? If that is the case and spi interrupt and timeout handler are running at the same interrupt level (will do that by default) then you are waiting on one interrupt to happen from another interrupt at the same level, which means that you will wait forever.