dmaengine/ste_dma40: fix memory leak due to prepared descriptors

Prepared descriptors that are not submitted will not be freed. Add
prepared descriptor to a list to be able to release them upon
dmaengine_terminate_all().

Signed-off-by: Per Forlin <per.forlin@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c
index 92ec0a26401a..467e4dcb20a0 100644
--- a/drivers/dma/ste_dma40.c
+++ b/drivers/dma/ste_dma40.c
@@ -177,6 +177,7 @@ struct d40_base;
  * @pending_queue: Submitted jobs, to be issued by issue_pending()
  * @active: Active descriptor.
  * @queue: Queued jobs.
+ * @prepare_queue: Prepared jobs.
  * @dma_cfg: The client configuration of this dma channel.
  * @configured: whether the dma_cfg configuration is valid
  * @base: Pointer to the device instance struct.
@@ -204,6 +205,7 @@ struct d40_chan {
         struct list_head                 pending_queue;
         struct list_head                 active;
         struct list_head                 queue;
+        struct list_head                 prepare_queue;
         struct stedma40_chan_cfg         dma_cfg;
         bool                             configured;
         struct d40_base                 *base;
@@ -833,6 +835,13 @@ static void d40_term_all(struct d40_chan *d40c)
                         d40_desc_free(d40c, d40d);
                 }
 
+        /* Release descriptors in prepare queue */
+        if (!list_empty(&d40c->prepare_queue))
+                list_for_each_entry_safe(d40d, _d,
+                                         &d40c->prepare_queue, node) {
+                        d40_desc_remove(d40d);
+                        d40_desc_free(d40c, d40d);
+                }
 
         d40c->pending_tx = 0;
         d40c->busy = false;
@@ -1911,6 +1920,12 @@ d40_prep_sg(struct dma_chan *dchan, struct scatterlist *sg_src,
                 goto err;
         }
 
+        /*
+         * add descriptor to the prepare queue in order to be able
+         * to free them later in terminate_all
+         */
+        list_add_tail(&desc->node, &chan->prepare_queue);
+
         spin_unlock_irqrestore(&chan->lock, flags);
 
         return &desc->txd;
@@ -2400,6 +2415,7 @@ static void __init d40_chan_init(struct d40_base *base, struct dma_device *dma,
                 INIT_LIST_HEAD(&d40c->queue);
                 INIT_LIST_HEAD(&d40c->pending_queue);
                 INIT_LIST_HEAD(&d40c->client);
+                INIT_LIST_HEAD(&d40c->prepare_queue);
 
                 tasklet_init(&d40c->tasklet, dma_tasklet,
                              (unsigned long) d40c);