From: Qiang Liu <qiang....@freescale.com>
- use spin_lock_bh() is the right way to use async_tx api,
dma_run_dependencies() should not be protected by spin_lock_irqsave();
- use spin_lock_bh to instead of spin_lock_irqsave for improving performance,
There is not any place to access descriptor queues in fsl-dma ISR except its
tasklet, spin_lock_bh() is more proper here. Interrupts will be turned off and
context will be save in irqsave, there is needless to use irqsave..
Cc: Dan Williams <dan.j.willi...@intel.com>
Cc: Vinod Koul <vinod.k...@intel.com>
Cc: Li Yang <le...@freescale.com>
Cc: Timur Tabi <ti...@freescale.com>
Signed-off-by: Qiang Liu <qiang....@freescale.com>
---
drivers/dma/fsldma.c | 30 ++++++++++++------------------
1 files changed, 12 insertions(+), 18 deletions(-)
diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c
index bb883c0..e3814aa 100644
--- a/drivers/dma/fsldma.c
+++ b/drivers/dma/fsldma.c
@@ -645,10 +645,9 @@ static dma_cookie_t fsl_dma_tx_submit(struct
dma_async_tx_descriptor *tx)
struct fsldma_chan *chan = to_fsl_chan(tx->chan);
struct fsl_desc_sw *desc = tx_to_fsl_desc(tx);
struct fsl_desc_sw *child;
- unsigned long flags;
dma_cookie_t cookie;
- spin_lock_irqsave(&chan->desc_lock, flags);
+ spin_lock_bh(&chan->desc_lock);
/*
* assign cookies to all of the software descriptors
@@ -661,7 +660,7 @@ static dma_cookie_t fsl_dma_tx_submit(struct
dma_async_tx_descriptor *tx)
/* put this transaction onto the tail of the pending queue */
append_ld_queue(chan, desc);
- spin_unlock_irqrestore(&chan->desc_lock, flags);
+ spin_unlock_bh(&chan->desc_lock);
return cookie;
}
@@ -770,15 +769,14 @@ static void fsldma_free_desc_list_reverse(struct
fsldma_chan *chan,
static void fsl_dma_free_chan_resources(struct dma_chan *dchan)
{
struct fsldma_chan *chan = to_fsl_chan(dchan);
- unsigned long flags;
chan_dbg(chan, "free all channel resources\n");
- spin_lock_irqsave(&chan->desc_lock, flags);
+ spin_lock_bh(&chan->desc_lock);
fsldma_cleanup_descriptor(chan);
fsldma_free_desc_list(chan, &chan->ld_pending);
fsldma_free_desc_list(chan, &chan->ld_running);
fsldma_free_desc_list(chan, &chan->ld_completed);
- spin_unlock_irqrestore(&chan->desc_lock, flags);
+ spin_unlock_bh(&chan->desc_lock);
dma_pool_destroy(chan->desc_pool);
chan->desc_pool = NULL;
@@ -997,7 +995,6 @@ static int fsl_dma_device_control(struct dma_chan *dchan,
{
struct dma_slave_config *config;
struct fsldma_chan *chan;
- unsigned long flags;
int size;
if (!dchan)
@@ -1007,7 +1004,7 @@ static int fsl_dma_device_control(struct dma_chan *dchan,
switch (cmd) {
case DMA_TERMINATE_ALL:
- spin_lock_irqsave(&chan->desc_lock, flags);
+ spin_lock_bh(&chan->desc_lock);
/* Halt the DMA engine */
dma_halt(chan);
@@ -1017,7 +1014,7 @@ static int fsl_dma_device_control(struct dma_chan *dchan,
fsldma_free_desc_list(chan, &chan->ld_running);
chan->idle = true;
- spin_unlock_irqrestore(&chan->desc_lock, flags);
+ spin_unlock_bh(&chan->desc_lock);
return 0;
case DMA_SLAVE_CONFIG:
@@ -1059,11 +1056,10 @@ static int fsl_dma_device_control(struct dma_chan
*dchan,
static void fsl_dma_memcpy_issue_pending(struct dma_chan *dchan)
{
struct fsldma_chan *chan = to_fsl_chan(dchan);
- unsigned long flags;
- spin_lock_irqsave(&chan->desc_lock, flags);
+ spin_lock_bh(&chan->desc_lock);
fsl_chan_xfer_ld_queue(chan);
- spin_unlock_irqrestore(&chan->desc_lock, flags);
+ spin_unlock_bh(&chan->desc_lock);
}
/**
@@ -1076,15 +1072,14 @@ static enum dma_status fsl_tx_status(struct dma_chan
*dchan,
{
struct fsldma_chan *chan = to_fsl_chan(dchan);
enum dma_status ret;
- unsigned long flags;
ret = dma_cookie_status(dchan, cookie, txstate);
if (ret == DMA_SUCCESS)
return ret;
- spin_lock_irqsave(&chan->desc_lock, flags);
+ spin_lock_bh(&chan->desc_lock);
fsldma_cleanup_descriptor(chan);
- spin_unlock_irqrestore(&chan->desc_lock, flags);
+ spin_unlock_bh(&chan->desc_lock);
return dma_cookie_status(dchan, cookie, txstate);
}
@@ -1163,11 +1158,10 @@ static irqreturn_t fsldma_chan_irq(int irq, void *data)
static void dma_do_tasklet(unsigned long data)
{
struct fsldma_chan *chan = (struct fsldma_chan *)data;
- unsigned long flags;
chan_dbg(chan, "tasklet entry\n");
- spin_lock_irqsave(&chan->desc_lock, flags);
+ spin_lock_bh(&chan->desc_lock);
/* the hardware is now idle and ready for more */
chan->idle = true;
@@ -1175,7 +1169,7 @@ static void dma_do_tasklet(unsigned long data)
/* Run all cleanup for this descriptor */
fsldma_cleanup_descriptor(chan);
- spin_unlock_irqrestore(&chan->desc_lock, flags);
+ spin_unlock_bh(&chan->desc_lock);
chan_dbg(chan, "tasklet exit\n");
}
--
1.7.5.1
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