dmaengine: PL08x: fix tx_status function to return correct residue

Now that we're converted to use the generic vchan support, we can fix
the residue return from tx_status to be compliant with dmaengine.  This
returns the number of bytes remaining for the _specified_ cookie, not
the number of bytes in all pending transfers on the channel.

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c
index 6a35e37..c42c7ef 100644 (file)
--- a/drivers/dma/amba-pl08x.c
+++ b/drivers/dma/amba-pl08x.c
@@ -473,10 +473,8 @@ static u32 pl08x_getbytes_chan(struct pl08x_dma_chan *plchan)
 {
        struct pl08x_phy_chan *ch;
        struct pl08x_txd *txd;
-       unsigned long flags;
        size_t bytes = 0;
 
-       spin_lock_irqsave(&plchan->vc.lock, flags);
        ch = plchan->phychan;
        txd = plchan->at;
 
@@ -516,27 +514,6 @@ static u32 pl08x_getbytes_chan(struct pl08x_dma_chan *plchan)
                }
        }
 
-       /* Sum up all queued transactions */
-       if (!list_empty(&plchan->vc.desc_issued)) {
-               struct pl08x_txd *txdi;
-               list_for_each_entry(txdi, &plchan->vc.desc_issued, vd.node) {
-                       struct pl08x_sg *dsg;
-                       list_for_each_entry(dsg, &txd->dsg_list, node)
-                               bytes += dsg->len;
-               }
-       }
-
-       if (!list_empty(&plchan->vc.desc_submitted)) {
-               struct pl08x_txd *txdi;
-               list_for_each_entry(txdi, &plchan->vc.desc_submitted, vd.node) {
-                       struct pl08x_sg *dsg;
-                       list_for_each_entry(dsg, &txd->dsg_list, node)
-                               bytes += dsg->len;
-               }
-       }
-
-       spin_unlock_irqrestore(&plchan->vc.lock, flags);
-
        return bytes;
 }
 
@@ -1171,23 +1148,53 @@ static enum dma_status pl08x_dma_tx_status(struct dma_chan *chan,
                dma_cookie_t cookie, struct dma_tx_state *txstate)
 {
        struct pl08x_dma_chan *plchan = to_pl08x_chan(chan);
+       struct virt_dma_desc *vd;
+       unsigned long flags;
        enum dma_status ret;
+       size_t bytes = 0;
 
        ret = dma_cookie_status(chan, cookie, txstate);
        if (ret == DMA_SUCCESS)
                return ret;
 
+       /*
+        * There's no point calculating the residue if there's
+        * no txstate to store the value.
+        */
+       if (!txstate) {
+               if (plchan->state == PL08X_CHAN_PAUSED)
+                       ret = DMA_PAUSED;
+               return ret;
+       }
+
+       spin_lock_irqsave(&plchan->vc.lock, flags);
+       ret = dma_cookie_status(chan, cookie, txstate);
+       if (ret != DMA_SUCCESS) {
+               vd = vchan_find_desc(&plchan->vc, cookie);
+               if (vd) {
+                       /* On the issued list, so hasn't been processed yet */
+                       struct pl08x_txd *txd = to_pl08x_txd(&vd->tx);
+                       struct pl08x_sg *dsg;
+
+                       list_for_each_entry(dsg, &txd->dsg_list, node)
+                               bytes += dsg->len;
+               } else {
+                       bytes = pl08x_getbytes_chan(plchan);
+               }
+       }
+       spin_unlock_irqrestore(&plchan->vc.lock, flags);
+
        /*
         * This cookie not complete yet
         * Get number of bytes left in the active transactions and queue
         */
-       dma_set_residue(txstate, pl08x_getbytes_chan(plchan));
+       dma_set_residue(txstate, bytes);
 
-       if (plchan->state == PL08X_CHAN_PAUSED)
-               return DMA_PAUSED;
+       if (plchan->state == PL08X_CHAN_PAUSED && ret == DMA_IN_PROGRESS)
+               ret = DMA_PAUSED;
 
        /* Whether waiting or running, we're in progress */
-       return DMA_IN_PROGRESS;
+       return ret;
 }
 
 /* PrimeCell DMA extension */