path: root/drivers/dma/dmaengine.c
diff options
authorGuennadi Liakhovetski <>2011-06-20 17:02:47 +0200
committerVinod Koul <>2011-06-24 16:13:16 +0530
commita03a202e95fdaa3ff52ccfc2594ec531e5917816 (patch)
tree872f242e564673c80be970bad141075d65b103da /drivers/dma/dmaengine.c
parente2f5e5a71dfe6bf155590de0fdd6d748ac79bf76 (diff)
dmaengine: failure to get a specific DMA channel is not critical
There exist systems with multiple DMA controllers with different capabilities. For example, on some sh-mobile / rmobile systems there are DMA controllers, whose channels can be configured to be used with SD- and MMC-host controllers, serial ports etc. Besides there are also DMA controllers, that can only be used for one special function, e.g., for USB. In such cases the DMA client filter function can just choose to specify to the DMA driver, which channel it needs. Then the .device_alloc_chan_resources() method of the DMA driver will check, whether it can provide that dunction. If not, it will fail and the loop in __dma_request_channel() will continue to the next DMA device, until it finds a suitable one. This works fine with just one minor glitch: the kernel logs error messages like dmaengine: failed to get <channel name>: (-<error code>) after each such non-critical failure. This patch lowers priority of this message to the debug level. Reported-by: Kuninori Morimoto <> Signed-off-by: Guennadi Liakhovetski <> Tested-by: Kuninori Morimoto <> Tested-by: Magnus Damm <> Signed-off-by: Vinod Koul <>
Diffstat (limited to 'drivers/dma/dmaengine.c')
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 8bcb15fb959d..f7f21a5de3e1 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -509,8 +509,8 @@ struct dma_chan *__dma_request_channel(dma_cap_mask_t *mask, dma_filter_fn fn, v
} else if (err)
- pr_err("dmaengine: failed to get %s: (%d)\n",
- dma_chan_name(chan), err);
+ pr_debug("dmaengine: failed to get %s: (%d)\n",
+ dma_chan_name(chan), err);
if (--device->privatecnt == 0)