dmaengine: dw: move residue to a descriptor

Residue is a property of any active descriptor. So, any descriptor may be in
different state but residue is a feature of active descriptor. Check if the
asked descriptor is active and return proper residue value for it.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

2 files changed, 41 insertions, 21 deletions

diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index 848d33507df9..a6d96f32f4f9 100644
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -242,7 +242,7 @@ static void dwc_dostart(struct dw_dma_chan *dwc, struct dw_desc *first)
 
                 dwc_initialize(dwc);
 
-                dwc->residue = first->total_len;
+                first->residue = first->total_len;
                 dwc->tx_node_active = &first->tx_list;
 
                 /* Submit first block */
@@ -372,11 +372,11 @@ 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;
+                                /* Update residue to reflect last sent descriptor */
+                                if (active == head->next)
+                                        desc->residue -= desc->len;
+                                else
+                                        desc->residue -= to_dw_desc(active->prev)->len;
 
                                 child = to_dw_desc(active);
 
@@ -391,8 +391,6 @@ static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
                         clear_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags);
                 }
 
-                dwc->residue = 0;
-
                 spin_unlock_irqrestore(&dwc->lock, flags);
 
                 dwc_complete_all(dw, dwc);
@@ -400,7 +398,6 @@ 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;
         }
@@ -415,7 +412,7 @@ static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
 
         list_for_each_entry_safe(desc, _desc, &dwc->active_list, desc_node) {
                 /* Initial residue value */
-                dwc->residue = desc->total_len;
+                desc->residue = desc->total_len;
 
                 /* Check first descriptors addr */
                 if (desc->txd.phys == DWC_LLP_LOC(llp)) {
@@ -426,20 +423,20 @@ static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
                 /* Check first descriptors llp */
                 if (lli_read(desc, llp) == llp) {
                         /* This one is currently in progress */
-                        dwc->residue -= dwc_get_sent(dwc);
+                        desc->residue -= dwc_get_sent(dwc);
                         spin_unlock_irqrestore(&dwc->lock, flags);
                         return;
                 }
 
-                dwc->residue -= desc->len;
+                desc->residue -= desc->len;
                 list_for_each_entry(child, &desc->tx_list, desc_node) {
                         if (lli_read(child, llp) == llp) {
                                 /* Currently in progress */
-                                dwc->residue -= dwc_get_sent(dwc);
+                                desc->residue -= dwc_get_sent(dwc);
                                 spin_unlock_irqrestore(&dwc->lock, flags);
                                 return;
                         }
-                        dwc->residue -= child->len;
+                        desc->residue -= child->len;
                 }
 
                 /*
@@ -1059,16 +1056,37 @@ static int dwc_terminate_all(struct dma_chan *chan)
         return 0;
 }
 
-static inline u32 dwc_get_residue(struct dw_dma_chan *dwc)
+static struct dw_desc *dwc_find_desc(struct dw_dma_chan *dwc, dma_cookie_t c)
+{
+        struct dw_desc *desc;
+
+        list_for_each_entry(desc, &dwc->active_list, desc_node)
+                if (desc->txd.cookie == c)
+                        return desc;
+
+        return NULL;
+}
+
+static u32 dwc_get_residue(struct dw_dma_chan *dwc, dma_cookie_t cookie)
 {
+        struct dw_desc *desc;
         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);
+        desc = dwc_find_desc(dwc, cookie);
+        if (desc) {
+                if (desc == dwc_first_active(dwc)) {
+                        residue = desc->residue;
+                        if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags) && residue)
+                                residue -= dwc_get_sent(dwc);
+                } else {
+                        residue = desc->total_len;
+                }
+        } else {
+                residue = 0;
+        }
 
         spin_unlock_irqrestore(&dwc->lock, flags);
         return residue;
@@ -1089,8 +1107,10 @@ dwc_tx_status(struct dma_chan *chan,
         dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
 
         ret = dma_cookie_status(chan, cookie, txstate);
-        if (ret != DMA_COMPLETE)
-                dma_set_residue(txstate, dwc_get_residue(dwc));
+        if (ret == DMA_COMPLETE)
+                return ret;
+
+        dma_set_residue(txstate, dwc_get_residue(dwc, cookie));
 
         if (test_bit(DW_DMA_IS_PAUSED, &dwc->flags) && ret == DMA_IN_PROGRESS)
                 return DMA_PAUSED;
diff --git a/drivers/dma/dw/regs.h b/drivers/dma/dw/regs.h
index 89178641e80b..96f498188257 100644
--- a/drivers/dma/dw/regs.h
+++ b/drivers/dma/dw/regs.h
@@ -237,7 +237,6 @@ struct dw_dma_chan {
         struct list_head        active_list;
         struct list_head        queue;
         struct list_head        free_list;
-        u32                     residue;
         struct dw_cyclic_desc   *cdesc;
 
         unsigned int            descs_allocated;
@@ -352,6 +351,7 @@ struct dw_desc {
         struct dma_async_tx_descriptor  txd;
         size_t                          len;
         size_t                          total_len;
+        u32                             residue;
 };
 
 #define to_dw_desc(h)   list_entry(h, struct dw_desc, desc_node)