The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 25962e1a7f1d522f1b57ead2f266fab570042a70 Mon Sep 17 00:00:00 2001 From: Frieder Schrempf <frieder.schrempf@xxxxxxxxxx> Date: Tue, 25 Feb 2020 08:23:20 +0000 Subject: [PATCH] dmaengine: imx-sdma: Fix the event id check to include RX event for UART6 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> diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c index 332ca5034504..4d4477df4ede 100644 --- a/drivers/dma/imx-sdma.c +++ b/drivers/dma/imx-sdma.c @@ -1331,7 +1331,7 @@ static void sdma_free_chan_resources(struct dma_chan *chan) 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); @@ -1632,7 +1632,7 @@ static int sdma_config(struct dma_chan *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);