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authorAndy Shevchenko <andriy.shevchenko@linux.intel.com>2013-01-25 11:48:03 +0200
committerVinod Koul <vinod.koul@intel.com>2013-01-28 04:04:50 -0800
commit4702d5244ca947263e8b7eb2ba6d8721e80c46e2 (patch)
tree127c5fdd5590467d781aca04685517e97d02bb01 /drivers/dma/dw_dmac.c
parent176dcec50f3f0bc46f11b983c1a3bbc2dd3514fd (diff)
dw_dmac: return proper residue value
Currently the driver returns full length of the active descriptor which is wrong. We have to go throught the active descriptor and substract the length of each sent children in the chain from the total length along with the actual data in the DMA channel registers. The cyclic case is not handled by this patch due to len field in the descriptor structure is left untouched by the original code. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma/dw_dmac.c')
-rw-r--r--drivers/dma/dw_dmac.c47
1 files changed, 45 insertions, 2 deletions
diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
index 5816da34129..35c8dd5f101 100644
--- 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;