dmaengine: stm32-dma: Add error messages if xlate fails

This patch adds some error messages when a slave device fails to request a
channel.

Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Reviewed-by: Ludovic BARRE <ludovic.barre@st.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

1 files changed, 15 insertions, 9 deletions

diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c
index fc9738e0f3a3..4eacd9dd5710 100644
--- a/drivers/dma/stm32-dma.c
+++ b/drivers/dma/stm32-dma.c
@@ -987,30 +987,36 @@ static struct dma_chan *stm32_dma_of_xlate(struct of_phandle_args *dma_spec,
                                            struct of_dma *ofdma)
 {
         struct stm32_dma_device *dmadev = ofdma->of_dma_data;
+        struct device *dev = dmadev->ddev.dev;
         struct stm32_dma_cfg cfg;
         struct stm32_dma_chan *chan;
         struct dma_chan *c;
 
-        if (dma_spec->args_count < 3)
+        if (dma_spec->args_count < 4) {
+                dev_err(dev, "Bad number of cells\n");
                 return NULL;
+        }
 
         cfg.channel_id = dma_spec->args[0];
         cfg.request_line = dma_spec->args[1];
         cfg.stream_config = dma_spec->args[2];
-        cfg.threshold = 0;
+        cfg.threshold = dma_spec->args[3];
 
-        if ((cfg.channel_id >= STM32_DMA_MAX_CHANNELS) || (cfg.request_line >=
-                                STM32_DMA_MAX_REQUEST_ID))
+        if ((cfg.channel_id >= STM32_DMA_MAX_CHANNELS) ||
+            (cfg.request_line >= STM32_DMA_MAX_REQUEST_ID)) {
+                dev_err(dev, "Bad channel and/or request id\n");
                 return NULL;
-
-        if (dma_spec->args_count > 3)
-                cfg.threshold = dma_spec->args[3];
+        }
 
         chan = &dmadev->chan[cfg.channel_id];
 
         c = dma_get_slave_channel(&chan->vchan.chan);
-        if (c)
-                stm32_dma_set_config(chan, &cfg);
+        if (!c) {
+                dev_err(dev, "No more channel avalaible\n");
+                return NULL;
+        }
+
+        stm32_dma_set_config(chan, &cfg);
 
         return c;
 }