dw_dmac: return proper residue value

[sfrench/cifs-2.6.git] / drivers / dma / dw_dmac.c

diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
index 5816da34129d70e6da0f69d4b5e7ed913fa25c89..35c8dd5f10133b6e2e0833a88cdf09db74d40422 100644 (file)
--- a/drivers/dma/dw_dmac.c
+++ b/drivers/dma/dw_dmac.c
@@ -282,6 +282,7 @@ static void dwc_dostart(struct dw_dma_chan *dwc, struct dw_desc *first)
 
                dwc_initialize(dwc);
 
+               dwc->residue = first->total_len;
                dwc->tx_node_active = &first->tx_list;
 
                /* Submit first block */
@@ -385,6 +386,15 @@ static void dwc_complete_all(struct dw_dma *dw, struct dw_dma_chan *dwc)
                dwc_descriptor_complete(dwc, desc, true);
 }
 
+/* Returns how many bytes were already received from source */
+static inline u32 dwc_get_sent(struct dw_dma_chan *dwc)
+{
+       u32 ctlhi = channel_readl(dwc, CTL_HI);
+       u32 ctllo = channel_readl(dwc, CTL_LO);
+
+       return (ctlhi & DWC_CTLH_BLOCK_TS_MASK) * (1 << (ctllo >> 4 & 7));
+}
+
 static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
 {
        dma_addr_t llp;
@@ -412,6 +422,12 @@ static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
 
                        head = &desc->tx_list;
                        if (active != head) {
+                               /* Update desc to reflect last sent one */
+                               if (active != head->next)
+                                       desc = to_dw_desc(active->prev);
+
+                               dwc->residue -= desc->len;
+
                                child = to_dw_desc(active);
 
                                /* Submit next block */
@@ -424,6 +440,9 @@ static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
                        /* We are done here */
                        clear_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags);
                }
+
+               dwc->residue = 0;
+
                spin_unlock_irqrestore(&dwc->lock, flags);
 
                dwc_complete_all(dw, dwc);
@@ -431,6 +450,7 @@ static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
        }
 
        if (list_empty(&dwc->active_list)) {
+               dwc->residue = 0;
                spin_unlock_irqrestore(&dwc->lock, flags);
                return;
        }
@@ -445,6 +465,9 @@ static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
                        (unsigned long long)llp);
 
        list_for_each_entry_safe(desc, _desc, &dwc->active_list, desc_node) {
+               /* initial residue value */
+               dwc->residue = desc->total_len;
+
                /* check first descriptors addr */
                if (desc->txd.phys == llp) {
                        spin_unlock_irqrestore(&dwc->lock, flags);
@@ -454,16 +477,21 @@ static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
                /* check first descriptors llp */
                if (desc->lli.llp == llp) {
                        /* This one is currently in progress */
+                       dwc->residue -= dwc_get_sent(dwc);
                        spin_unlock_irqrestore(&dwc->lock, flags);
                        return;
                }
 
-               list_for_each_entry(child, &desc->tx_list, desc_node)
+               dwc->residue -= desc->len;
+               list_for_each_entry(child, &desc->tx_list, desc_node) {
                        if (child->lli.llp == llp) {
                                /* Currently in progress */
+                               dwc->residue -= dwc_get_sent(dwc);
                                spin_unlock_irqrestore(&dwc->lock, flags);
                                return;
                        }
+                       dwc->residue -= child->len;
+               }
 
                /*
                 * No descriptors so far seem to be in progress, i.e.
@@ -1054,6 +1082,21 @@ static int dwc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
        return 0;
 }
 
+static inline u32 dwc_get_residue(struct dw_dma_chan *dwc)
+{
+       unsigned long flags;
+       u32 residue;
+
+       spin_lock_irqsave(&dwc->lock, flags);
+
+       residue = dwc->residue;
+       if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags) && residue)
+               residue -= dwc_get_sent(dwc);
+
+       spin_unlock_irqrestore(&dwc->lock, flags);
+       return residue;
+}
+
 static enum dma_status
 dwc_tx_status(struct dma_chan *chan,
              dma_cookie_t cookie,
@@ -1070,7 +1113,7 @@ dwc_tx_status(struct dma_chan *chan,
        }
 
        if (ret != DMA_SUCCESS)
-               dma_set_residue(txstate, dwc_first_active(dwc)->len);
+               dma_set_residue(txstate, dwc_get_residue(dwc));
 
        if (dwc->paused)
                return DMA_PAUSED;