On Friday 17 October 2008, Mark Jackson wrote:David,+ /* Can tx_buf and rx_buf be equal? The doc in spi.h is not sure... */you use the same buffer a few functions below. either
+ xfer.tx_buf = chip->tx_buf;
+ xfer.rx_buf = chip->rx_buf;
one way or the other. please investigate with the spi subsystem maintainer.
Just to double check (as per Alessandro's suggestion), is this okay use of the spi buffers ?
Yes. That comment deserves to be updated.
SPI does bi-directional I/O, and the underlying controller
should be able to just replace the contents of a buffer
with a spi_transfer that uses the same rx and tx buffers.