DMAENGINE: ste_dma40: avoid doing unnessecary suspend
Jonas Aaberg [Sun, 20 Jun 2010 21:25:46 +0000 (21:25 +0000)]
Avoid doing unnessecary suspend when modifying logical channels.

Signed-off-by: Jonas Aaberg <jonas.aberg@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/dma/ste_dma40.c

index ebffb53..abbc1b6 100644 (file)
@@ -595,6 +595,7 @@ static void d40_config_set_event(struct d40_chan *d40c, bool do_enable)
        u32 val;
        unsigned long flags;
 
+       /* Notice, that disable requires the physical channel to be stopped */
        if (do_enable)
                val = D40_ACTIVATE_EVENTLINE;
        else
@@ -740,18 +741,10 @@ static dma_cookie_t d40_tx_submit(struct dma_async_tx_descriptor *tx)
 
 static int d40_start(struct d40_chan *d40c)
 {
-       int err;
-
-       if (d40c->log_num != D40_PHY_CHAN) {
-               err = d40_channel_execute_command(d40c, D40_DMA_SUSPEND_REQ);
-               if (err)
-                       return err;
+       if (d40c->log_num != D40_PHY_CHAN)
                d40_config_set_event(d40c, true);
-       }
-
-       err = d40_channel_execute_command(d40c, D40_DMA_RUN);
 
-       return err;
+       return d40_channel_execute_command(d40c, D40_DMA_RUN);
 }
 
 static struct d40_desc *d40_queue_start(struct d40_chan *d40c)
@@ -1340,7 +1333,6 @@ static bool d40_is_paused(struct d40_chan *d40c)
        void __iomem *active_reg;
        u32 status;
        u32 event;
-       int res;
 
        spin_lock_irqsave(&d40c->lock, flags);
 
@@ -1359,10 +1351,6 @@ static bool d40_is_paused(struct d40_chan *d40c)
                goto _exit;
        }
 
-       res = d40_channel_execute_command(d40c, D40_DMA_SUSPEND_REQ);
-       if (res != 0)
-               goto _exit;
-
        if (d40c->dma_cfg.dir == STEDMA40_MEM_TO_PERIPH ||
            d40c->dma_cfg.dir == STEDMA40_MEM_TO_MEM)
                event = D40_TYPE_TO_EVENT(d40c->dma_cfg.dst_dev_type);
@@ -1379,12 +1367,6 @@ static bool d40_is_paused(struct d40_chan *d40c)
 
        if (status != D40_DMA_RUN)
                is_paused = true;
-
-       /* Resume the other logical channels if any */
-       if (d40_chan_has_events(d40c))
-               res = d40_channel_execute_command(d40c,
-                                                 D40_DMA_RUN);
-
 _exit:
        spin_unlock_irqrestore(&d40c->lock, flags);
        return is_paused;
@@ -1430,20 +1412,13 @@ static int d40_resume(struct dma_chan *chan)
 
        spin_lock_irqsave(&d40c->lock, flags);
 
-       if (d40c->log_num != D40_PHY_CHAN) {
-               res = d40_channel_execute_command(d40c, D40_DMA_SUSPEND_REQ);
-               if (res)
-                       goto out;
-
-               /* If bytes left to transfer or linked tx resume job */
-               if (d40_residue(d40c) || d40_tx_is_linked(d40c)) {
+       /* If bytes left to transfer or linked tx resume job */
+       if (d40_residue(d40c) || d40_tx_is_linked(d40c)) {
+               if (d40c->log_num != D40_PHY_CHAN)
                        d40_config_set_event(d40c, true);
-                       res = d40_channel_execute_command(d40c, D40_DMA_RUN);
-               }
-       } else if (d40_residue(d40c) || d40_tx_is_linked(d40c))
                res = d40_channel_execute_command(d40c, D40_DMA_RUN);
+       }
 
-out:
        spin_unlock_irqrestore(&d40c->lock, flags);
        return res;
 }