4.13-stable review patch. If anyone has any objections, please let me know.
------------------ From: Peter Ujfalusi <[email protected]> commit 2ccb4837c938357233a0b8818e3ca3e58242c952 upstream. 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: ec9bfa1e1a796 ("dmaengine: ti-dma-crossbar: dra7: Use bitops instead of idr") Signed-off-by: Peter Ujfalusi <[email protected]> Signed-off-by: Vinod Koul <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/dma/ti-dma-crossbar.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/dma/ti-dma-crossbar.c +++ b/drivers/dma/ti-dma-crossbar.c @@ -262,13 +262,14 @@ static void *ti_dra7_xbar_route_allocate 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];
