From: Vladimir Oltean <vladimir.oltean@nxp.com>
Date: Wed, 18 Mar 2020 02:15:59 +0200
Subject: spi: spi-fsl-dspi: Fix interrupt-less DMA mode taking an XSPI code
 path

Git-commit: 826b3a6a34619b934cdc33eeb961fcb99ce92c09
Patch-mainline: v5.7-rc1
References: jsc#SLE-12251

Interrupts are not necessary for DMA functionality, since the completion
event is provided by the DMA driver.

But if the driver fails to request the IRQ defined in the device tree,
it will call dspi_poll which would make the driver hang waiting for data
to become available in the RX FIFO.

Fixes: c55be3059159 ("spi: spi-fsl-dspi: Use poll mode in case the platform IRQ is missing")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20200318001603.9650-9-olteanv@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@suse.com>
---
 drivers/spi/spi-fsl-dspi.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c
index 81e22b6eadc7..fcc6f20b6631 100644
--- a/drivers/spi/spi-fsl-dspi.c
+++ b/drivers/spi/spi-fsl-dspi.c
@@ -965,13 +965,15 @@ static int dspi_transfer_one_message(struct spi_controller *ctlr,
 			goto out;
 		}
 
-		if (!dspi->irq) {
-			do {
-				status = dspi_poll(dspi);
-			} while (status == -EINPROGRESS);
-		} else if (trans_mode != DSPI_DMA_MODE) {
-			wait_for_completion(&dspi->xfer_done);
-			reinit_completion(&dspi->xfer_done);
+		if (trans_mode != DSPI_DMA_MODE) {
+			if (dspi->irq) {
+				wait_for_completion(&dspi->xfer_done);
+				reinit_completion(&dspi->xfer_done);
+			} else {
+				do {
+					status = dspi_poll(dspi);
+				} while (status == -EINPROGRESS);
+			}
 		}
 
 		spi_transfer_delay_exec(transfer);
-- 
2.26.2