diff options
Diffstat (limited to 'drivers/spi/spi.c')
| -rw-r--r-- | drivers/spi/spi.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 6fa56590bba2..d4ba723a30da 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -778,6 +778,17 @@ static void spi_set_cs(struct spi_device *spi, bool enable) { bool enable1 = enable; + /* + * Avoid calling into the driver (or doing delays) if the chip select + * isn't actually changing from the last time this was called. + */ + if ((spi->controller->last_cs_enable == enable) && + (spi->controller->last_cs_mode_high == (spi->mode & SPI_CS_HIGH))) + return; + + spi->controller->last_cs_enable = enable; + spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH; + if (!spi->controller->set_cs_timing) { if (enable1) spi_delay_exec(&spi->controller->cs_setup, NULL); |