[PATCH v2 14/15] dmaengine: dw: move residue to a descriptor

Andy Shevchenko
2016-02-22T16:04:22Z

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: Mans Rullgard <mans@mansr.com>
---
drivers/dma/dw/core.c | 60 ++++++++++++++++++++++++++++++++++-----------------
drivers/dma/dw/regs.h | 2 +-
2 files changed, 41 insertions(+), 21 deletions(-)

diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index dbf026c..cce0619 100644
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -238,7 +238,7 @@ 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 */
@@ -369,11 +369,11 @@ 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);

@@ -388,8 +388,6 @@ 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);
@@ -397,7 +395,6 @@ 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;
}
@@ -412,7 +409,7 @@ 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)) {
@@ -423,20 +420,20 @@ 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;
}

/*
@@ -1039,16 +1036,37 @@ 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;
@@ -1069,8 +1087,10 @@ 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 2c0561d..5b3ea2d 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;
@@ -351,6 +350,7 @@ 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)
--
2.7.0