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Diffstat (limited to 'drivers/spi/spidev.c')
-rw-r--r--drivers/spi/spidev.c17
1 files changed, 11 insertions, 6 deletions
diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c
index 5d869c4d3eb..606e7a40a8d 100644
--- a/drivers/spi/spidev.c
+++ b/drivers/spi/spidev.c
@@ -58,15 +58,20 @@ static unsigned long minors[N_SPI_MINORS / BITS_PER_LONG];
/* Bit masks for spi_device.mode management. Note that incorrect
- * settings for CS_HIGH and 3WIRE can cause *lots* of trouble for other
- * devices on a shared bus: CS_HIGH, because this device will be
- * active when it shouldn't be; 3WIRE, because when active it won't
- * behave as it should.
+ * settings for some settings can cause *lots* of trouble for other
+ * devices on a shared bus:
*
- * REVISIT should changing those two modes be privileged?
+ * - CS_HIGH ... this device will be active when it shouldn't be
+ * - 3WIRE ... when active, it won't behave as it should
+ * - NO_CS ... there will be no explicit message boundaries; this
+ * is completely incompatible with the shared bus model
+ * - READY ... transfers may proceed when they shouldn't.
+ *
+ * REVISIT should changing those flags be privileged?
*/
#define SPI_MODE_MASK (SPI_CPHA | SPI_CPOL | SPI_CS_HIGH \
- | SPI_LSB_FIRST | SPI_3WIRE | SPI_LOOP)
+ | SPI_LSB_FIRST | SPI_3WIRE | SPI_LOOP \
+ | SPI_NO_CS | SPI_READY)
struct spidev_data {
dev_t devt;