From: Frieder Schrempf <frieder.schrempf@xxxxxxxxxx> commit 25962e1a7f1d522f1b57ead2f266fab570042a70 upstream. On i.MX6UL/ULL and i.MX6SX the DMA event id for the RX channel of UART6 is '0'. To fix the broken DMA support for UART6, we change the check for event_id0 to include '0' as a valid id. Fixes: 1ec1e82f2510 ("dmaengine: Add Freescale i.MX SDMA support") Signed-off-by: Frieder Schrempf <frieder.schrempf@xxxxxxxxxx> Reviewed-by: Fabio Estevam <festevam@xxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Link: https://lore.kernel.org/r/20200225082139.7646-1-frieder.schrempf@xxxxxxxxxx Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/dma/imx-sdma.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/dma/imx-sdma.c +++ b/drivers/dma/imx-sdma.c @@ -1328,7 +1328,7 @@ static void sdma_free_chan_resources(str sdma_channel_synchronize(chan); - if (sdmac->event_id0) + if (sdmac->event_id0 >= 0) sdma_event_disable(sdmac, sdmac->event_id0); if (sdmac->event_id1) sdma_event_disable(sdmac, sdmac->event_id1); @@ -1629,7 +1629,7 @@ static int sdma_config(struct dma_chan * memcpy(&sdmac->slave_config, dmaengine_cfg, sizeof(*dmaengine_cfg)); /* Set ENBLn earlier to make sure dma request triggered after that */ - if (sdmac->event_id0) { + if (sdmac->event_id0 >= 0) { if (sdmac->event_id0 >= sdmac->sdma->drvdata->num_events) return -EINVAL; sdma_event_enable(sdmac, sdmac->event_id0);