On Sat, May 23, 2020 at 12:29 AM Mark Brown <broonie@xxxxxxxxxx> wrote: > > On Fri, May 22, 2020 at 11:59:25PM +0800, dillon min wrote: > > > but, after spi-core create a dummy tx_buf or rx_buf, then i can't get > > the correct spi_3wire direction. > > actually, this dummy tx_buf is useless for SPI_3WIRE. it's has meaning > > for SPI_SIMPLE_RX mode, > > simulate SPI_FULL_DUMPLEX > > Oh, that's annoying. I think the fix here is in the core, it should > ignore MUST_TX and MUST_RX in 3WIRE mode since they clearly make no > sense there. How about add below changes to spi-core diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 8994545..bfd465c 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1022,7 +1022,8 @@ static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg) void *tmp; unsigned int max_tx, max_rx; - if (ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX)) { + if ((ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX)) && + !(msg->spi->mode & SPI_3WIRE)) { max_tx = 0; max_rx = 0; for my board, lcd panel ilitek ill9341 use 3wire mode, gyro l3gd20 use simplex rx mode. it's has benefits to l3gd20, no impact to ili9341. if it's fine to spi-core, i will include it to my next submits. thanks best regards. Dillon _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel