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>
diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
index 5816da3..35c8dd5 100644
--- a/drivers/dma/dw_dmac.c
+++ b/drivers/dma/dw_dmac.c
@@ -282,6 +282,7 @@
dwc_initialize(dwc);
+ dwc->residue = first->total_len;
dwc->tx_node_active = &first->tx_list;
/* Submit first block */
@@ -385,6 +386,15 @@
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 @@
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 @@
/* 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 @@
}
if (list_empty(&dwc->active_list)) {
+ dwc->residue = 0;
spin_unlock_irqrestore(&dwc->lock, flags);
return;
}
@@ -445,6 +465,9 @@
(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 @@
/* 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 @@
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 @@
}
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;