Messages in this thread Patch in this message | | | Date | Thu, 21 Feb 2008 00:54:32 +0900 (JST) | Subject | [PATCH] atmel_spi: support zero length transfer | From | Atsushi Nemoto <> |
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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; }
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