spi: spi-fsl-dspi: Fix interrupt-less DMA mode taking an XSPI code path

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>

diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c
index 81e22b6eadc78e7dedb4650e3943889b0ac9cee0..fcc6f20b6631105f510fd38df8531c31cd88b0ac 100644 (file)
--- 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);