[PATCH 1/3] dmaengine: virt-dma: don't always free descriptor upon completion
From: Vinod Koul <hidden>
Date: 2015-09-24 17:23:40
Also in:
lkml
On Sun, Sep 06, 2015 at 01:40:52PM +0200, Robert Jarzmik wrote:
quoted hunk ↗ jump to hunk
@@ -29,7 +29,7 @@ dma_cookie_t vchan_tx_submit(struct dma_async_tx_descriptor *tx) spin_lock_irqsave(&vc->lock, flags); cookie = dma_cookie_assign(tx); - list_add_tail(&vd->node, &vc->desc_submitted); + list_move_tail(&vd->node, &vc->desc_submitted);
I am not sure I follow this, why move ?
+int vchan_tx_desc_free(struct dma_async_tx_descriptor *tx)
+{
+ struct virt_dma_chan *vc = to_virt_chan(tx->chan);
+ struct virt_dma_desc *vd = to_virt_desc(tx);
+ unsigned long flags;
+
+ spin_lock_irqsave(&vc->lock, flags);
+ list_del(&vd->node);
+ spin_unlock_irqrestore(&vc->lock, flags);
+
+ dev_dbg(vc->chan.device->dev, "vchan %p: txd %p[%x]: freeing\n",
+ vc, vd, vd->tx.cookie);
+ vc->desc_free(vd);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(vchan_tx_desc_free);this one seems okay, can you add comments here and also update documentation for this
quoted hunk ↗ jump to hunk
@@ -96,9 +115,13 @@ void vchan_dma_desc_free_list(struct virt_dma_chan *vc, struct list_head *head) while (!list_empty(head)) { struct virt_dma_desc *vd = list_first_entry(head, struct virt_dma_desc, node); - list_del(&vd->node); - dev_dbg(vc->chan.device->dev, "txd %p: freeing\n", vd); - vc->desc_free(vd); + if (dmaengine_desc_test_reuse(&vd->tx)) { + list_move_tail(&vd->node, &vc->desc_allocated);
should we check this if the list is to be freed? Why would anyone call free except when cleaning up ?
static inline void vchan_free_chan_resources(struct virt_dma_chan *vc)
{
+ struct virt_dma_desc *vd;
unsigned long flags;
LIST_HEAD(head);
spin_lock_irqsave(&vc->lock, flags);
vchan_get_all_descriptors(vc, &head);
+ list_for_each_entry(vd, &head, node)
+ dmaengine_desc_clear_reuse(&vd->tx);why do we want to do this, if we are freeing them -- ~Vinod