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Commit d2f4f99d authored by Maxime Ripard's avatar Maxime Ripard Committed by Vinod Koul
Browse files

dmaengine: Rework dma_chan_get 



dma_chan_get uses a rather interesting error handling and code path.

Change it to something more usual in the kernel.

Signed-off-by: default avatarMaxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarVinod Koul <vinod.koul@intel.com>
parent ceacbdbf

drivers/dma/dmaengine.c

+19 −17
Original line number Diff line number Diff line
@@ -222,31 +222,33 @@ static void balance_ref_count(struct dma_chan *chan) 
 */

static int dma_chan_get(struct dma_chan *chan)

{

	int err = -ENODEV;

	struct module *owner = dma_chan_to_owner(chan);

	int ret;



	/* The channel is already in use, update client count */

	if (chan->client_count) {

		__module_get(owner);

		err = 0;

	} else if (try_module_get(owner))

		err = 0;

		goto out;

	}



	if (err == 0)

		chan->client_count++;

	if (!try_module_get(owner))

		return -ENODEV;



	/* allocate upon first client reference */

	if (chan->client_count == 1 && err == 0) {

		int desc_cnt = chan->device->device_alloc_chan_resources(chan);

	ret = chan->device->device_alloc_chan_resources(chan);

	if (ret < 0)

		goto err_out;



		if (desc_cnt < 0) {

			err = desc_cnt;

			chan->client_count = 0;

			module_put(owner);

		} else if (!dma_has_cap(DMA_PRIVATE, chan->device->cap_mask))

	if (!dma_has_cap(DMA_PRIVATE, chan->device->cap_mask))

		balance_ref_count(chan);

	}



	return err;

out:

	chan->client_count++;

	return 0;



err_out:

	module_put(owner);

	return ret;

}



/**