Merge tag 'dmaengine-4.7-rc1' of git://git.infradead.org/users/vkoul/slave-dma

Pull dmaengine updates from Vinod Koul:
 "This time round the update brings in following changes:

   - new tegra driver for ADMA device

   - support for Xilinx AXI Direct Memory Access Engine and Xilinx AXI
     Central Direct Memory Access Engine and few updates to this driver

   - new cyclic capability to sun6i and few updates

   - slave-sg support in bcm2835

   - updates to many drivers like designware, hsu, mv_xor, pxa, edma,
     qcom_hidma & bam"

* tag 'dmaengine-4.7-rc1' of git://git.infradead.org/users/vkoul/slave-dma: (84 commits)
  dmaengine: ioatdma: disable relaxed ordering for ioatdma
  dmaengine: of_dma: approximate an average distribution
  dmaengine: core: Use IS_ENABLED() instead of checking for built-in or module
  dmaengine: edma: Re-evaluate errors when ccerr is triggered w/o error event
  dmaengine: qcom_hidma: add support for object hierarchy
  dmaengine: qcom_hidma: add debugfs hooks
  dmaengine: qcom_hidma: implement lower level hardware interface
  dmaengine: vdma: Add clock support
  Documentation: DT: vdma: Add clock support for dmas
  dmaengine: vdma: Add config structure to differentiate dmas
  MAINTAINERS: Update Tegra DMA maintainers
  dmaengine: tegra-adma: Add support for Tegra210 ADMA
  Documentation: DT: Add binding documentation for NVIDIA ADMA
  dmaengine: vdma: Add Support for Xilinx AXI Central Direct Memory Access Engine
  Documentation: DT: vdma: update binding doc for AXI CDMA
  dmaengine: vdma: Add Support for Xilinx AXI Direct Memory Access Engine
  Documentation: DT: vdma: update binding doc for AXI DMA
  dmaengine: vdma: Rename xilinx_vdma_ prefix to xilinx_dma
  dmaengine: slave means at least one of DMA_SLAVE, DMA_CYCLIC
  dmaengine: mv_xor: Allow selecting mv_xor for mvebu only compatible SoC
  ...

1 files changed, 10 insertions, 2 deletions

diff --git a/drivers/dma/of-dma.c b/drivers/dma/of-dma.c
index 1e1f2986eba8..faae0bfe1109 100644
--- a/drivers/dma/of-dma.c
+++ b/drivers/dma/of-dma.c
@@ -240,8 +240,9 @@ struct dma_chan *of_dma_request_slave_channel(struct device_node *np,
 	struct of_phandle_args	dma_spec;
 	struct of_dma		*ofdma;
 	struct dma_chan		*chan;
-	int			count, i;
+	int			count, i, start;
 	int			ret_no_channel = -ENODEV;
+	static atomic_t		last_index;
 
 	if (!np || !name) {
 		pr_err("%s: not enough information provided\n", __func__);
@@ -259,8 +260,15 @@ struct dma_chan *of_dma_request_slave_channel(struct device_node *np,
 		return ERR_PTR(-ENODEV);
 	}
 
+	/*
+	 * approximate an average distribution across multiple
+	 * entries with the same name
+	 */
+	start = atomic_inc_return(&last_index);
 	for (i = 0; i < count; i++) {
-		if (of_dma_match_channel(np, name, i, &dma_spec))
+		if (of_dma_match_channel(np, name,
+					 (i + start) % count,
+					 &dma_spec))
 			continue;
 
 		mutex_lock(&of_dma_lock);