spi: rockchip: Signal unfinished DMA transfers

When using DMA, the transfer_one callback should return 1 because the
transfer hasn't finished yet.

A previous commit changed the function to return 0 when the DMA channels
were correctly prepared.

This manifested in Veyron boards with this message:

[ 1.983605] cros-ec-spi spi0.0: EC failed to respond in time

Fixes: ea9849113343 ("spi: rockchip: check return value of dmaengine_prep_slave_sg")
Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c
index cd89682..1026e18 100644 (file)
--- a/drivers/spi/spi-rockchip.c
+++ b/drivers/spi/spi-rockchip.c
@@ -578,7 +578,7 @@ static int rockchip_spi_transfer_one(
                struct spi_device *spi,
                struct spi_transfer *xfer)
 {
-       int ret = 1;
+       int ret = 0;
        struct rockchip_spi *rs = spi_master_get_devdata(master);
 
        WARN_ON(readl_relaxed(rs->regs + ROCKCHIP_SPI_SSIENR) &&
@@ -627,6 +627,8 @@ static int rockchip_spi_transfer_one(
                        spi_enable_chip(rs, 1);
                        ret = rockchip_spi_prepare_dma(rs);
                }
+               /* successful DMA prepare means the transfer is in progress */
+               ret = ret ? ret : 1;
        } else {
                spi_enable_chip(rs, 1);
                ret = rockchip_spi_pio_transfer(rs);