DMAENGINE: COH 901 318 remove irq counting

This removes the pointless irq counting for the COH 901 318, as
it turns out the hardware will only ever fire one IRQ for a linked
list anyway. In the process also a missing spinlock was introduced.

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

2 files changed, 34 insertions, 55 deletions

diff --git a/drivers/dma/coh901318.c b/drivers/dma/coh901318.c
index 12a7a151be6a..544c46278f84 100644
--- a/drivers/dma/coh901318.c
+++ b/drivers/dma/coh901318.c
@@ -39,7 +39,6 @@ struct coh901318_desc {
         unsigned int sg_len;
         struct coh901318_lli *data;
         enum dma_data_direction dir;
-        int pending_irqs;
         unsigned long flags;
 };
 
@@ -72,7 +71,6 @@ struct coh901318_chan {
 
         unsigned long nbr_active_done;
         unsigned long busy;
-        int pending_irqs;
 
         struct coh901318_base *base;
 };
@@ -368,10 +366,6 @@ static void
 coh901318_desc_submit(struct coh901318_chan *cohc, struct coh901318_desc *desc)
 {
         list_add_tail(&desc->node, &cohc->active);
-
-        BUG_ON(cohc->pending_irqs != 0);
-
-        cohc->pending_irqs = desc->pending_irqs;
 }
 
 static struct coh901318_desc *
@@ -617,36 +611,30 @@ static void dma_tasklet(unsigned long data)
         /* get first active descriptor entry from list */
         cohd_fin = coh901318_first_active_get(cohc);
 
-        BUG_ON(cohd_fin->pending_irqs == 0);
-
         if (cohd_fin == NULL)
                 goto err;
 
-        cohd_fin->pending_irqs--;
-        cohc->completed = cohd_fin->desc.cookie;
+        /* locate callback to client */
+        callback = cohd_fin->desc.callback;
+        callback_param = cohd_fin->desc.callback_param;
 
-        if (cohc->nbr_active_done == 0)
-                return;
+        /* sign this job as completed on the channel */
+        cohc->completed = cohd_fin->desc.cookie;
 
-        if (!cohd_fin->pending_irqs) {
-                /* release the lli allocation*/
-                coh901318_lli_free(&cohc->base->pool, &cohd_fin->data);
-        }
+        /* release the lli allocation and remove the descriptor */
+        coh901318_lli_free(&cohc->base->pool, &cohd_fin->data);
 
-        dev_vdbg(COHC_2_DEV(cohc), "[%s] chan_id %d pending_irqs %d"
-                 " nbr_active_done %ld\n", __func__,
-                 cohc->id, cohc->pending_irqs, cohc->nbr_active_done);
+        /* return desc to free-list */
+        coh901318_desc_remove(cohd_fin);
+        coh901318_desc_free(cohc, cohd_fin);
 
-        /* callback to client */
-        callback = cohd_fin->desc.callback;
-        callback_param = cohd_fin->desc.callback_param;
+        spin_unlock_irqrestore(&cohc->lock, flags);
 
-        if (!cohd_fin->pending_irqs) {
-                coh901318_desc_remove(cohd_fin);
+        /* Call the callback when we're done */
+        if (callback)
+                callback(callback_param);
 
-                /* return desc to free-list */
-                coh901318_desc_free(cohc, cohd_fin);
-        }
+        spin_lock_irqsave(&cohc->lock, flags);
 
         /*
          * If another interrupt fired while the tasklet was scheduling,
@@ -655,9 +643,7 @@ static void dma_tasklet(unsigned long data)
          * be handled for this channel. If there happen to be more than
          * one IRQ to be ack:ed, we simply schedule this tasklet again.
          */
-        if (cohc->nbr_active_done)
-                cohc->nbr_active_done--;
-
+        cohc->nbr_active_done--;
         if (cohc->nbr_active_done) {
                 dev_dbg(COHC_2_DEV(cohc), "scheduling tasklet again, new IRQs "
                         "came in while we were scheduling this tasklet\n");
@@ -666,10 +652,8 @@ static void dma_tasklet(unsigned long data)
                 else
                         tasklet_schedule(&cohc->tasklet);
         }
-        spin_unlock_irqrestore(&cohc->lock, flags);
 
-        if (callback)
-                callback(callback_param);
+        spin_unlock_irqrestore(&cohc->lock, flags);
 
         return;
 
@@ -688,16 +672,17 @@ static void dma_tc_handle(struct coh901318_chan *cohc)
         if (!cohc->allocated)
                 return;
 
-        BUG_ON(cohc->pending_irqs == 0);
+        spin_lock(&cohc->lock);
 
-        cohc->pending_irqs--;
         cohc->nbr_active_done++;
 
-        if (cohc->pending_irqs == 0 && coh901318_queue_start(cohc) == NULL)
+        if (coh901318_queue_start(cohc) == NULL)
                 cohc->busy = 0;
 
         BUG_ON(list_empty(&cohc->active));
 
+        spin_unlock(&cohc->lock);
+
         if (cohc_chan_conf(cohc)->priority_high)
                 tasklet_hi_schedule(&cohc->tasklet);
         else
@@ -951,6 +936,7 @@ coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
         u32 ctrl = cohc_chan_param(cohc)->ctrl_lli;
         u32 ctrl_last = cohc_chan_param(cohc)->ctrl_lli_last;
         unsigned long flg;
+        int ret;
 
         if (!sgl)
                 goto out;
@@ -1010,13 +996,14 @@ coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
                 goto err_dma_alloc;
 
         /* initiate allocated data list */
-        cohd->pending_irqs =
-                coh901318_lli_fill_sg(&cohc->base->pool, data, sgl, sg_len,
-                                      cohc_dev_addr(cohc),
-                                      ctrl_chained,
-                                      ctrl,
-                                      ctrl_last,
-                                      direction, COH901318_CX_CTRL_TC_IRQ_ENABLE);
+        ret = coh901318_lli_fill_sg(&cohc->base->pool, data, sgl, sg_len,
+                                    cohc_dev_addr(cohc),
+                                    ctrl_chained,
+                                    ctrl,
+                                    ctrl_last,
+                                    direction, COH901318_CX_CTRL_TC_IRQ_ENABLE);
+        if (ret)
+                goto err_lli_fill;
 
         COH_DBG(coh901318_list_print(cohc, data));
 
@@ -1030,6 +1017,7 @@ coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
         spin_unlock_irqrestore(&cohc->lock, flg);
 
         return &cohd->desc;
+ err_lli_fill:
  err_dma_alloc:
  err_direction:
         spin_unlock_irqrestore(&cohc->lock, flg);
@@ -1121,7 +1109,6 @@ coh901318_terminate_all(struct dma_chan *chan)
 
         cohc->nbr_active_done = 0;
         cohc->busy = 0;
-        cohc->pending_irqs = 0;
 
         spin_unlock_irqrestore(&cohc->lock, flags);
 }
@@ -1148,7 +1135,6 @@ void coh901318_base_init(struct dma_device *dma, const int *pick_chans,
 
                         spin_lock_init(&cohc->lock);
 
-                        cohc->pending_irqs = 0;
                         cohc->nbr_active_done = 0;
                         cohc->busy = 0;
                         INIT_LIST_HEAD(&cohc->free);
diff --git a/drivers/dma/coh901318_lli.c b/drivers/dma/coh901318_lli.c
index f5120f238a4d..5f9af1956eab 100644
--- a/drivers/dma/coh901318_lli.c
+++ b/drivers/dma/coh901318_lli.c
@@ -166,8 +166,7 @@ coh901318_lli_fill_memcpy(struct coh901318_pool *pool,
         lli->src_addr = src;
         lli->dst_addr = dst;
 
-        /* One irq per single transfer */
-        return 1;
+        return 0;
 }
 
 int
@@ -223,8 +222,7 @@ coh901318_lli_fill_single(struct coh901318_pool *pool,
         lli->src_addr = src;
         lli->dst_addr = dst;
 
-        /* One irq per single transfer */
-        return 1;
+        return 0;
 }
 
 int
@@ -240,7 +238,6 @@ coh901318_lli_fill_sg(struct coh901318_pool *pool,
         u32 ctrl_sg;
         dma_addr_t src = 0;
         dma_addr_t dst = 0;
-        int nbr_of_irq = 0;
         u32 bytes_to_transfer;
         u32 elem_size;
 
@@ -269,9 +266,6 @@ coh901318_lli_fill_sg(struct coh901318_pool *pool,
                         ctrl_sg = ctrl ? ctrl : ctrl_last;
 
 
-                if ((ctrl_sg & ctrl_irq_mask))
-                        nbr_of_irq++;
-
                 if (dir == DMA_TO_DEVICE)
                         /* increment source address */
                         src = sg_dma_address(sg);
@@ -310,8 +304,7 @@ coh901318_lli_fill_sg(struct coh901318_pool *pool,
         }
         spin_unlock(&pool->lock);
 
-        /* There can be many IRQs per sg transfer */
-        return nbr_of_irq;
+        return 0;
  err:
         spin_unlock(&pool->lock);
         return -EINVAL;