[PATCH] dmaengine: imx-sdma: only restart cyclic channel when enabled

[PATCH] dmaengine: imx-sdma: only restart cyclic channel when enabled

[Sascha Hauer]

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>
---
 drivers/dma/imx-sdma.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
index 8535018ee7a2e..5356cce41bffc 100644
--- 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);
 	}
-- 
2.30.2

Re: [PATCH] dmaengine: imx-sdma: only restart cyclic channel when enabled

[Vinod Koul]

On 17-06-22, 13:50, Sascha Hauer wrote:
> 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()).

Applied, thanks

-- 
~Vinod