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Commit 2ccb4837 authored by Peter Ujfalusi's avatar Peter Ujfalusi Committed by Vinod Koul
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dmaengine: ti-dma-crossbar: Fix possible race condition with dma_inuse 



When looking for unused xbar_out lane we should also protect the set_bit()
call with the same mutex to protect against concurrent threads picking the
same ID.

Fixes: ec9bfa1e ("dmaengine: ti-dma-crossbar: dra7: Use bitops instead of idr")
Signed-off-by: default avatarPeter Ujfalusi <peter.ujfalusi@ti.com>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarVinod Koul <vinod.koul@intel.com>
parent 87a2f622

drivers/dma/ti-dma-crossbar.c

+2 −1
Original line number Diff line number Diff line
@@ -262,13 +262,14 @@ static void *ti_dra7_xbar_route_allocate(struct of_phandle_args *dma_spec, 
	mutex_lock(&xbar->mutex);

	map->xbar_out = find_first_zero_bit(xbar->dma_inuse,

					    xbar->dma_requests);

	mutex_unlock(&xbar->mutex);

	if (map->xbar_out == xbar->dma_requests) {

		mutex_unlock(&xbar->mutex);

		dev_err(&pdev->dev, "Run out of free DMA requests\n");

		kfree(map);

		return ERR_PTR(-ENOMEM);

	}

	set_bit(map->xbar_out, xbar->dma_inuse);

	mutex_unlock(&xbar->mutex);



	map->xbar_in = (u16)dma_spec->args[0];