[PATCH 2/2] dma: tegra20-apbdma: channel freeing correction

[Dmitry Osipenko <digetx-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

Fixed channel "lock" after free.

Example: Channel 1 was allocated and prepared as slave_sg, used and freed. Now preparation of cyclic dma on channel 1 will fail with err "DMA
configuration conflict" because tdc->isr_handler still selected to handle_once_dma_done.

This happens because tegra_dma_abort_all() won't be called on channel freeing if pending list is empty.

Signed-off-by: Dmitry Osipenko <digetx-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 drivers/dma/tegra20-apb-dma.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c
index 4d816be..00c5dee 100644
--- a/drivers/dma/tegra20-apb-dma.c
+++ b/drivers/dma/tegra20-apb-dma.c
@@ -1147,6 +1147,7 @@ static void tegra_dma_free_chan_resources(struct dma_chan *dc)
 
 	if (tdc->busy)
 		tegra_dma_terminate_all(dc);
+	tdc->isr_handler = NULL;
 
 	spin_lock_irqsave(&tdc->lock, flags);
 	list_splice_init(&tdc->pending_sg_req, &sg_req_list);
-- 
1.7.12