[PATCH 2/5] dmaengine: virt-dma: Do not call desc_free() under a spin_lock

[Sascha Hauer <s.hauer@pengutronix.de>]

vchan_vdesc_fini() shouldn't be called under a spin_lock. This is done
in two places, once in vchan_terminate_vdesc() and once in
vchan_synchronize(). Instead of freeing the vdesc right away, collect
the aborted vdescs on a separate list and free them along with the other
vdescs.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 drivers/dma/virt-dma.c |  1 +
 drivers/dma/virt-dma.h | 17 +++--------------
 2 files changed, 4 insertions(+), 14 deletions(-)

diff --git a/drivers/dma/virt-dma.c b/drivers/dma/virt-dma.c
index ec4adf4260a0..87d5bd53c98b 100644
--- a/drivers/dma/virt-dma.c
+++ b/drivers/dma/virt-dma.c
@@ -135,6 +135,7 @@ void vchan_init(struct virt_dma_chan *vc, struct dma_device *dmadev)
 	INIT_LIST_HEAD(&vc->desc_submitted);
 	INIT_LIST_HEAD(&vc->desc_issued);
 	INIT_LIST_HEAD(&vc->desc_completed);
+	INIT_LIST_HEAD(&vc->desc_aborted);
 
 	tasklet_init(&vc->task, vchan_complete, (unsigned long)vc);
 
diff --git a/drivers/dma/virt-dma.h b/drivers/dma/virt-dma.h
index 41883ee2c29f..6cae93624f0d 100644
--- a/drivers/dma/virt-dma.h
+++ b/drivers/dma/virt-dma.h
@@ -31,9 +31,9 @@ struct virt_dma_chan {
 	struct list_head desc_submitted;
 	struct list_head desc_issued;
 	struct list_head desc_completed;
+	struct list_head desc_aborted;
 
 	struct virt_dma_desc *cyclic;
-	struct virt_dma_desc *vd_terminated;
 };
 
 static inline struct virt_dma_chan *to_virt_chan(struct dma_chan *chan)
@@ -146,11 +146,8 @@ static inline void vchan_terminate_vdesc(struct virt_dma_desc *vd)
 {
 	struct virt_dma_chan *vc = to_virt_chan(vd->tx.chan);
 
-	/* free up stuck descriptor */
-	if (vc->vd_terminated)
-		vchan_vdesc_fini(vc->vd_terminated);
+	list_add_tail(&vd->node, &vc->desc_aborted);
 
-	vc->vd_terminated = vd;
 	if (vc->cyclic == vd)
 		vc->cyclic = NULL;
 }
@@ -184,6 +181,7 @@ static inline void vchan_get_all_descriptors(struct virt_dma_chan *vc,
 	list_splice_tail_init(&vc->desc_submitted, head);
 	list_splice_tail_init(&vc->desc_issued, head);
 	list_splice_tail_init(&vc->desc_completed, head);
+	list_splice_tail_init(&vc->desc_aborted, head);
 }
 
 static inline void vchan_free_chan_resources(struct virt_dma_chan *vc)
@@ -212,16 +210,7 @@ static inline void vchan_free_chan_resources(struct virt_dma_chan *vc)
  */
 static inline void vchan_synchronize(struct virt_dma_chan *vc)
 {
-	unsigned long flags;
-
 	tasklet_kill(&vc->task);
-
-	spin_lock_irqsave(&vc->lock, flags);
-	if (vc->vd_terminated) {
-		vchan_vdesc_fini(vc->vd_terminated);
-		vc->vd_terminated = NULL;
-	}
-	spin_unlock_irqrestore(&vc->lock, flags);
 }
 
 #endif
-- 
2.24.0