A spi transfer with zero length is not invalid. Such transfer can be
used to achieve delay before first CLK edge after chipselect assertion.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
---
diff --git a/drivers/spi/atmel_spi.c b/drivers/spi/atmel_spi.c
index 293b7ca..5dff5e0 100644
--- a/drivers/spi/atmel_spi.c
+++ b/drivers/spi/atmel_spi.c
@@ -606,7 +606,7 @@ static int atmel_spi_transfer(struct spi_device *spi, struct spi_message *msg)
return -ESHUTDOWN;
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
- if (!(xfer->tx_buf || xfer->rx_buf)) {
+ if (!(xfer->tx_buf || xfer->rx_buf) && xfer->len) {
dev_dbg(&spi->dev, "missing rx or tx buf\n");
return -EINVAL;
}
--
