The ad7298 drivers buffer implementation uses the IIO kfifo buffer, so it needs to select IIO_KFIFO_BUF. Otherwise (if no other driver selects the symbol) the following linker error will occur: drivers/built-in.o: In function `ad7298_register_ring_funcs_and_init': (.text+0x245cf2): undefined reference to `iio_kfifo_allocate' drivers/built-in.o: In function `ad7298_register_ring_funcs_and_init': (.text+0x245d7d): undefined reference to `iio_kfifo_free' drivers/built-in.o: In function `ad7298_ring_cleanup': (.text+0x245dcd): undefined reference to `iio_kfifo_free' Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx> Reported-by: Randy Dunlap <rdunlap@xxxxxxxxxxxx> --- The patch is only required for 3.5-rc1+. Versions prior to 3.5-rc1 require a different patch (IIO_SW_RING instead of IIO_KFIFO_BUF) which I'll send to stable once this patch is in Linus' tree. --- drivers/staging/iio/adc/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/staging/iio/adc/Kconfig b/drivers/staging/iio/adc/Kconfig index 2490dd2..8f1b3af 100644 --- a/drivers/staging/iio/adc/Kconfig +++ b/drivers/staging/iio/adc/Kconfig @@ -13,6 +13,7 @@ config AD7291 config AD7298 tristate "Analog Devices AD7298 ADC driver" depends on SPI + select IIO_KFIFO_BUF if IIO_BUFFER help Say yes here to build support for Analog Devices AD7298 8 Channel ADC with temperature sensor. -- 1.7.10 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel