contiki-os/contiki — pull request #754 by wwhuang (2014-07-22 03:29:21+00:00)
Title: [CC2538] Fix SPI_FLUSH

The current SPI_FLUSH macro first waits for the SPI RX FIFO to fill with something. So if an application makes a SPI_FLUSH call and the RX FIFO happens to already be empty, the application stalls.