From a03a202e95fdaa3ff52ccfc2594ec531e5917816 Mon Sep 17 00:00:00 2001 From: Guennadi Liakhovetski Date: Mon, 20 Jun 2011 17:02:47 +0200 Subject: 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 : (-) 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 --- drivers/dma/dmaengine.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/dma/dmaengine.c') diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index 8bcb15fb959..f7f21a5de3e 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 dma_chan_name(chan)); list_del_rcu(&device->global_node); } 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); else break; if (--device->privatecnt == 0) -- cgit v1.2.3-70-g09d2 From 21ef4b8b7a7d59a995bf44382de38c95587767d4 Mon Sep 17 00:00:00 2001 From: Axel Lin Date: Wed, 20 Jul 2011 11:32:28 +0800 Subject: dmaengine: use DEFINE_IDR for static initialization We could use DEFINE_IDR for statically allocated idr that allow us to save a few lines of code. And also remove unneeded mutex_init() for dma_list_mutex, as dma_list_mutex is initialized automatically by DEFINE_MUTEX(). Signed-off-by: Axel Lin Signed-off-by: Dan Williams --- drivers/dma/dmaengine.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'drivers/dma/dmaengine.c') diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index 8bcb15fb959..bc11eebff44 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -61,9 +61,9 @@ #include static DEFINE_MUTEX(dma_list_mutex); +static DEFINE_IDR(dma_idr); static LIST_HEAD(dma_device_list); static long dmaengine_ref_count; -static struct idr dma_idr; /* --- sysfs implementation --- */ @@ -1049,8 +1049,6 @@ EXPORT_SYMBOL_GPL(dma_run_dependencies); static int __init dma_bus_init(void) { - idr_init(&dma_idr); - mutex_init(&dma_list_mutex); return class_register(&dma_devclass); } arch_initcall(dma_bus_init); -- cgit v1.2.3-70-g09d2