dmaengine: imx-sdma: only restart cyclic channel when enabled

An interrupt for a channel might be pending even after struct
dma_device::device_terminate_all has been called. In that case the
recently introduced warning message "restart cyclic channel..." triggers
and the channel will be restarted. This is not desired as the channel
has just been stopped. Only restart the channel when we still have a
descriptor set for it (which will be set to NULL in
sdma_terminate_all()).

Fixes: 5b215c28b9235 ("dmaengine: imx-sdma: restart cyclic channel if needed")
Cc: stable@vger.kernel.org
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Link: https://lore.kernel.org/r/20220617115042.4004062-1-s.hauer@pengutronix.de
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
index 900cafdaf3594c75996f8a4255085e11dbd5cf34..f37a276f519e6ef91c64a1319d55ce3af9b392fc 100644 (file)
--- a/drivers/dma/imx-sdma.c
+++ b/drivers/dma/imx-sdma.c
@@ -891,7 +891,7 @@ static void sdma_update_channel_loop(struct sdma_channel *sdmac)
         * SDMA stops cyclic channel when DMA request triggers a channel and no SDMA
         * owned buffer is available (i.e. BD_DONE was set too late).
         */
-       if (!is_sdma_channel_enabled(sdmac->sdma, sdmac->channel)) {
+       if (sdmac->desc && !is_sdma_channel_enabled(sdmac->sdma, sdmac->channel)) {
                dev_warn(sdmac->sdma->dev, "restart cyclic channel %d\n", sdmac->channel);
                sdma_enable_channel(sdmac->sdma, sdmac->channel);
        }