Lock scenario: 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 setted to handle_once_dma_done.
This happens because tegra_dma_abort_all() won't be called on channel freeing
if pending list is empty and channel not busy. We need to clear isr_handler
on channel freeing to avoid locking.
Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
---
I have sent this fix some month ago and Laxman gave his ack, but since that
time I found that it's not right to include multiple changes in one patch,
so converted it to trivial change.
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 a84bb7f..c541276 100644
--- a/drivers/dma/tegra20-apb-dma.c
+++ b/drivers/dma/tegra20-apb-dma.c
@@ -1191,6 +1191,7 @@ static void tegra_dma_free_chan_resources(struct dma_chan *dc)
list_splice_init(&tdc->free_dma_desc, &dma_desc_list);
INIT_LIST_HEAD(&tdc->cb_desc);
tdc->config_init = false;
+ tdc->isr_handler = NULL;
spin_unlock_irqrestore(&tdc->lock, flags);
while (!list_empty(&dma_desc_list)) {
--
1.8.2.1
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