2 files changed, 14 insertions, 0 deletions

diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c
index 650e2bbc7aad..bf6f7d02c9f6 100644
--- a/drivers/dma/amba-pl08x.c
+++ b/drivers/dma/amba-pl08x.c
@@ -959,6 +959,7 @@ static int prep_phy_channel(struct pl08x_dma_chan *plchan,
                  ch->signal,
                  plchan->name);
 
+        plchan->phychan_hold++;
         plchan->phychan = ch;
 
         return 0;
@@ -998,6 +999,8 @@ static dma_cookie_t pl08x_tx_submit(struct dma_async_tx_descriptor *tx)
                 /* Do this memcpy whenever there is a channel ready */
                 plchan->state = PL08X_CHAN_WAITING;
                 plchan->waiting = txd;
+        } else {
+                plchan->phychan_hold--;
         }
 
         /* This unlock follows the lock in the prep() function */
@@ -1585,6 +1588,7 @@ static void pl08x_tasklet(unsigned long data)
                  */
                 plchan->lc = txd->tx.cookie;
         }
+
         /*
          * If a new descriptor is queued, set it up
          * plchan->at is NULL here
@@ -1598,6 +1602,12 @@ static void pl08x_tasklet(unsigned long data)
                 list_del(&next->node);
 
                 pl08x_start_txd(plchan, next);
+        } else if (plchan->phychan_hold) {
+                /*
+                 * This channel is still in use - we have a new txd being
+                 * prepared and will soon be queued.  Don't give up the
+                 * physical channel.
+                 */
         } else {
                 struct pl08x_dma_chan *waiting = NULL;
 
@@ -1625,6 +1635,7 @@ static void pl08x_tasklet(unsigned long data)
                                 ret = prep_phy_channel(waiting,
                                                        waiting->waiting);
                                 BUG_ON(ret);
+                                waiting->phychan_hold--;
                                 waiting->state = PL08X_CHAN_RUNNING;
                                 waiting->waiting = NULL;
                                 pl08x_issue_pending(&waiting->chan);
diff --git a/include/linux/amba/pl08x.h b/include/linux/amba/pl08x.h
index 08a9024e2d2f..95b76ea1829f 100644
--- a/include/linux/amba/pl08x.h
+++ b/include/linux/amba/pl08x.h
@@ -151,6 +151,8 @@ enum pl08x_dma_chan_state {
  * struct pl08x_dma_chan - this structure wraps a DMA ENGINE channel
  * @chan: wrappped abstract channel
  * @phychan: the physical channel utilized by this channel, if there is one
+ * @phychan_hold: if non-zero, hold on to the physical channel even if we
+ *  have no pending entries
  * @tasklet: tasklet scheduled by the IRQ to handle actual work etc
  * @name: name of channel
  * @cd: channel platform data
@@ -173,6 +175,7 @@ enum pl08x_dma_chan_state {
 struct pl08x_dma_chan {
         struct dma_chan chan;
         struct pl08x_phy_chan *phychan;
+        int phychan_hold;
         struct tasklet_struct tasklet;
         char *name;
         struct pl08x_channel_data *cd;