dmaengine: at_xdmac: Drop locking in at_xdmac_alloc_chan_resources() (387269d0) · Commits · 戴 / test

There is no need for locking in device_alloc_chan_resources(), the DMA core takes care of it by using a dma_list_mutex around the DMA devices. Signed-off-by:

Tudor Ambarus <tudor.ambarus@microchip.com> Acked-by:

Ludovic Desroches <ludovic.desroches@microchip.com> Link: https://lore.kernel.org/r/20200123140237.125799-8-tudor.ambarus@microchip.com Signed-off-by:

Vinod Koul <vkoul@kernel.org>

drivers/dma/at_xdmac.c

+2 −9

Original line number	Diff line number	Diff line
		@@ -1820,22 +1820,17 @@ static int at_xdmac_alloc_chan_resources(struct dma_chan *chan)
		struct at_xdmac_chan *atchan = to_at_xdmac_chan(chan);
		struct at_xdmac_desc *desc;
		int i;
		unsigned long flags;

		spin_lock_irqsave(&atchan->lock, flags);

		if (at_xdmac_chan_is_enabled(atchan)) {
		dev_err(chan2dev(chan),
		"can't allocate channel resources (channel enabled)\n");
		i = -EIO;
		goto spin_unlock;
		return -EIO;
		}

		if (!list_empty(&atchan->free_descs_list)) {
		dev_err(chan2dev(chan),
		"can't allocate channel resources (channel not free from a previous use)\n");
		i = -EIO;
		goto spin_unlock;
		return -EIO;
		}

		for (i = 0; i < init_nr_desc_per_channel; i++) {
		@@ -1852,8 +1847,6 @@ static int at_xdmac_alloc_chan_resources(struct dma_chan *chan)

		dev_dbg(chan2dev(chan), "%s: allocated %d descriptors\n", __func__, i);

		spin_unlock:
		spin_unlock_irqrestore(&atchan->lock, flags);
		return i;
		}

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