summaryrefslogtreecommitdiff
path: root/drivers/dma/qcom
diff options
context:
space:
mode:
authorSinan Kaya <okaya@codeaurora.org>2016-08-31 11:10:27 -0400
committerVinod Koul <vinod.koul@intel.com>2016-08-31 21:27:32 +0530
commit8a31f8b5db65b860fd0d358dc27f6daf26074406 (patch)
tree2464951e1e9b2eaa2930294abe5c2c2b685bb35c /drivers/dma/qcom
parent73fc45e3ce7838e6f47228dd51144c492931e8ad (diff)
dmaengine: qcom_hidma: release the descriptor before the callback
There is a race condition between data transfer callback and descriptor free code. The callback routine may decide to clear the resources even though the descriptor has not yet been freed. Instead of calling the callback first and then releasing the memory, this code is changing the order to return the descriptor back to the free pool and then call the user provided callback. Signed-off-by: Sinan Kaya <okaya@codeaurora.org> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma/qcom')
-rw-r--r--drivers/dma/qcom/hidma.c18
1 files changed, 10 insertions, 8 deletions
diff --git a/drivers/dma/qcom/hidma.c b/drivers/dma/qcom/hidma.c
index 1197fbf8f30e..b8493bafdb3f 100644
--- a/drivers/dma/qcom/hidma.c
+++ b/drivers/dma/qcom/hidma.c
@@ -111,6 +111,7 @@ static void hidma_process_completed(struct hidma_chan *mchan)
struct dma_async_tx_descriptor *desc;
dma_cookie_t last_cookie;
struct hidma_desc *mdesc;
+ struct hidma_desc *next;
unsigned long irqflags;
struct list_head list;
@@ -122,8 +123,9 @@ static void hidma_process_completed(struct hidma_chan *mchan)
spin_unlock_irqrestore(&mchan->lock, irqflags);
/* Execute callbacks and run dependencies */
- list_for_each_entry(mdesc, &list, node) {
+ list_for_each_entry_safe(mdesc, next, &list, node) {
enum dma_status llstat;
+ struct dmaengine_desc_callback cb;
desc = &mdesc->desc;
@@ -132,18 +134,18 @@ static void hidma_process_completed(struct hidma_chan *mchan)
spin_unlock_irqrestore(&mchan->lock, irqflags);
llstat = hidma_ll_status(mdma->lldev, mdesc->tre_ch);
- if (llstat == DMA_COMPLETE)
- dmaengine_desc_get_callback_invoke(desc, NULL);
+ dmaengine_desc_get_callback(desc, &cb);
last_cookie = desc->cookie;
dma_run_dependencies(desc);
- }
- /* Free descriptors */
- spin_lock_irqsave(&mchan->lock, irqflags);
- list_splice_tail_init(&list, &mchan->free);
- spin_unlock_irqrestore(&mchan->lock, irqflags);
+ spin_lock_irqsave(&mchan->lock, irqflags);
+ list_move(&mdesc->node, &mchan->free);
+ spin_unlock_irqrestore(&mchan->lock, irqflags);
+ if (llstat == DMA_COMPLETE)
+ dmaengine_desc_callback_invoke(&cb, NULL);
+ }
}
/*