spi: spi-geni-qcom: enable SPI_CONTROLLER_MUST_TX for GPI DMA mode

[ Upstream commit d10005837be83906bbd2078c3b4f9dfcbd6c95b6 ]

The GPI DMA mode requires for TX DMA to be prepared. Force SPI core to
provide TX buffer even if the caller didn't provide one by setting the
SPI_CONTROLLER_MUST_TX flag.

Fixes: b59c122484ec ("spi: spi-geni-qcom: Add support for GPI dma")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20230629095847.3648597-1-dmitry.baryshkov@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/spi/spi-geni-qcom.c b/drivers/spi/spi-geni-qcom.c
index 689b94fc5570aff543466d2d1a13a944d6ece349..7b76dcd11e2bb54580505428dec6dc521906d769 100644 (file)
--- a/drivers/spi/spi-geni-qcom.c
+++ b/drivers/spi/spi-geni-qcom.c
@@ -979,6 +979,12 @@ static int spi_geni_probe(struct platform_device *pdev)
        if (mas->cur_xfer_mode == GENI_SE_FIFO)
                spi->set_cs = spi_geni_set_cs;
 
+       /*
+        * TX is required per GSI spec, see setup_gsi_xfer().
+        */
+       if (mas->cur_xfer_mode == GENI_GPI_DMA)
+               spi->flags = SPI_CONTROLLER_MUST_TX;
+
        ret = request_irq(mas->irq, geni_spi_isr, 0, dev_name(dev), spi);
        if (ret)
                goto spi_geni_release_dma;