dmaengine: dw: Enable runtime PM (84206794) · Commits · 戴 / test

When consumer requests channel power on the DMA controller device and otherwise on the freeing channel resources. Note, in some cases consumer acquires channel at the ->probe() stage and releases it at the ->remove() stage. It will mean that DMA controller device will be powered during all this time if there is no assist from hardware to idle it. The above mentioned cases should be investigated separately and individually. Signed-off-by:

Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by:

Viresh Kumar <viresh.kumar@linaro.org> Link: https://lore.kernel.org/r/20201103183938.64752-1-andriy.shevchenko@linux.intel.com Signed-off-by:

Vinod Koul <vkoul@kernel.org>

drivers/dma/dw/core.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -982,8 +982,11 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan)

		dev_vdbg(chan2dev(chan), "%s\n", __func__);

		pm_runtime_get_sync(dw->dma.dev);

		/* ASSERT: channel is idle */
		if (dma_readl(dw, CH_EN) & dwc->mask) {
		pm_runtime_put_sync_suspend(dw->dma.dev);
		dev_dbg(chan2dev(chan), "DMA channel not idle?\n");
		return -EIO;
		}
		@@ -1000,6 +1003,7 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan)
		* We need controller-specific data to set up slave transfers.
		*/
		if (chan->private && !dw_dma_filter(chan, chan->private)) {
		pm_runtime_put_sync_suspend(dw->dma.dev);
		dev_warn(chan2dev(chan), "Wrong controller-specific data\n");
		return -EINVAL;
		}
		@@ -1043,6 +1047,8 @@ static void dwc_free_chan_resources(struct dma_chan *chan)
		if (!dw->in_use)
		do_dw_dma_off(dw);

		pm_runtime_put_sync_suspend(dw->dma.dev);

		dev_vdbg(chan2dev(chan), "%s: done\n", __func__);
		}

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