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authorPeter Ujfalusi <peter.ujfalusi@ti.com>2017-09-21 14:35:32 +0300
committerVinod Koul <vinod.koul@intel.com>2017-09-21 20:33:42 +0300
commit2ccb4837c938357233a0b8818e3ca3e58242c952 (patch)
tree8fad3dac3958c7bbceb583cd940d34efde1d536e /drivers/dma/ti-dma-crossbar.c
parent87a2f622cc6446c7d09ac655b7b9b04886f16a4c (diff)
downloadlinux-2ccb4837c938357233a0b8818e3ca3e58242c952.tar.xz
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: ec9bfa1e1a796 ("dmaengine: ti-dma-crossbar: dra7: Use bitops instead of idr") Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Cc: stable@vger.kernel.org Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma/ti-dma-crossbar.c')
-rw-r--r--drivers/dma/ti-dma-crossbar.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/dma/ti-dma-crossbar.c b/drivers/dma/ti-dma-crossbar.c
index 2f65a8fde21d..f1d04b70ee67 100644
--- 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(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];