[PATCH 7/9] dmaengine: stm32-dma: Add error messages if xlate fails

From: M'boumba Cedric Madianga
Date: Tue Dec 13 2016 - 08:41:29 EST


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

Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@xxxxxxxxx>
Reviewed-by: Ludovic BARRE <ludovic.barre@xxxxxx>
---
drivers/dma/stm32-dma.c | 19 ++++++++++++++-----
1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c
index ba929a9..35639f6 100644
--- a/drivers/dma/stm32-dma.c
+++ b/drivers/dma/stm32-dma.c
@@ -975,27 +975,36 @@ 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 < 4)
+ 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 = 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;
+ }

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;
}
--
1.9.1