spi: spi-rspi: Fix PIO fallback on RZ platforms

RSPI IP on RZ/{A, G2L} SoC's has the same signal for both interrupt
and DMA transfer request. Setting DMARS register for DMA transfer
makes the signal to work as a DMA transfer request signal and
subsequent interrupt requests to the interrupt controller
are masked.

PIO fallback does not work as interrupt signal is disabled.

This patch fixes this issue by re-enabling the interrupts by
calling dmaengine_synchronize().

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20220721143449.879257-1-biju.das.jz@bp.renesas.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index 7a014eeec2d0d9a2072a4190042d14ffe14bf454..411b1307b7fd82679ecd17678bf5d7b64ba3e906 100644 (file)
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -613,6 +613,10 @@ static int rspi_dma_transfer(struct rspi_data *rspi, struct sg_table *tx,
                                               rspi->dma_callbacked, HZ);
        if (ret > 0 && rspi->dma_callbacked) {
                ret = 0;
+               if (tx)
+                       dmaengine_synchronize(rspi->ctlr->dma_tx);
+               if (rx)
+                       dmaengine_synchronize(rspi->ctlr->dma_rx);
        } else {
                if (!ret) {
                        dev_err(&rspi->ctlr->dev, "DMA timeout\n");