From db90a44177ac39fc22b2da5235b231fccdd4c673 Mon Sep 17 00:00:00 2001 From: Sourav Poddar Date: Thu, 22 Aug 2013 21:20:48 +0530 Subject: [PATCH] spi: conditional checking of mode and transfer bits. There is a bug in the following patch: http://comments.gmane.org/gmane.linux.kernel.spi.devel/14420 spi: DUAL and QUAD support fix the previous patch some mistake below: 1. DT in slave node, use "spi-tx-nbits = <1/2/4>" in place of using "spi-tx-dual, spi-tx-quad" directly, same to rx. So correct the previous way to get the property in @of_register_spi_devices(). 2. Change the value of transfer bit macro(SPI_NBITS_SINGLE, SPI_NBITS_DUAL SPI_NBITS_QUAD) to 0x01, 0x02 and 0x04 to match the actual wires. 3. Add the following check (1)keep the tx_nbits and rx_nbits in spi_transfer is not beyond the single, dual and quad. (2)keep tx_nbits and rx_nbits are contained by @spi_device->mode example: if @spi_device->mode = DUAL, then tx/rx_nbits can not be set to QUAD(SPI_NBITS_QUAD) (3)if "@spi_device->mode & SPI_3WIRE", then tx/rx_nbits should be in single(SPI_NBITS_SINGLE) Checking of the tx/rx transfer bits and mode bits should be done conditionally based on type of buffer filled else EINVAL condition will always get hit either for rx or tx. Signed-off-by: Sourav Poddar Signed-off-by: Mark Brown --- drivers/spi/spi.c | 56 +++++++++++++++++++++++++---------------------- 1 file changed, 30 insertions(+), 26 deletions(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 39d38756e984..50f7fc3ed793 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1473,33 +1473,37 @@ static int __spi_async(struct spi_device *spi, struct spi_message *message) * 2. keep tx/rx_nbits is contained by mode in spi_device * 3. if SPI_3WIRE, tx/rx_nbits should be in single */ - if (xfer->tx_nbits != SPI_NBITS_SINGLE && - xfer->tx_nbits != SPI_NBITS_DUAL && - xfer->tx_nbits != SPI_NBITS_QUAD) - return -EINVAL; - if ((xfer->tx_nbits == SPI_NBITS_DUAL) && - !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD))) - return -EINVAL; - if ((xfer->tx_nbits == SPI_NBITS_QUAD) && - !(spi->mode & SPI_TX_QUAD)) - return -EINVAL; - if ((spi->mode & SPI_3WIRE) && - (xfer->tx_nbits != SPI_NBITS_SINGLE)) - return -EINVAL; + if (xfer->tx_buf) { + if (xfer->tx_nbits != SPI_NBITS_SINGLE && + xfer->tx_nbits != SPI_NBITS_DUAL && + xfer->tx_nbits != SPI_NBITS_QUAD) + return -EINVAL; + if ((xfer->tx_nbits == SPI_NBITS_DUAL) && + !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD))) + return -EINVAL; + if ((xfer->tx_nbits == SPI_NBITS_QUAD) && + !(spi->mode & SPI_TX_QUAD)) + return -EINVAL; + if ((spi->mode & SPI_3WIRE) && + (xfer->tx_nbits != SPI_NBITS_SINGLE)) + return -EINVAL; + } /* check transfer rx_nbits */ - if (xfer->rx_nbits != SPI_NBITS_SINGLE && - xfer->rx_nbits != SPI_NBITS_DUAL && - xfer->rx_nbits != SPI_NBITS_QUAD) - return -EINVAL; - if ((xfer->rx_nbits == SPI_NBITS_DUAL) && - !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD))) - return -EINVAL; - if ((xfer->rx_nbits == SPI_NBITS_QUAD) && - !(spi->mode & SPI_RX_QUAD)) - return -EINVAL; - if ((spi->mode & SPI_3WIRE) && - (xfer->rx_nbits != SPI_NBITS_SINGLE)) - return -EINVAL; + if (xfer->rx_buf) { + if (xfer->rx_nbits != SPI_NBITS_SINGLE && + xfer->rx_nbits != SPI_NBITS_DUAL && + xfer->rx_nbits != SPI_NBITS_QUAD) + return -EINVAL; + if ((xfer->rx_nbits == SPI_NBITS_DUAL) && + !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD))) + return -EINVAL; + if ((xfer->rx_nbits == SPI_NBITS_QUAD) && + !(spi->mode & SPI_RX_QUAD)) + return -EINVAL; + if ((spi->mode & SPI_3WIRE) && + (xfer->rx_nbits != SPI_NBITS_SINGLE)) + return -EINVAL; + } } message->spi = spi; -- 2.20.1