Messages in this thread Patch in this message | | | From | <> | Subject | [PATCH v5 5/6] fsl-dma: use spin_lock_bh to instead of spin_lock_irqsave | Date | Wed, 1 Aug 2012 16:50:09 +0800 |
| |
From: Qiang Liu <qiang.liu@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.williams@intel.com> Cc: Vinod Koul <vinod.koul@intel.com> Cc: Li Yang <leoli@freescale.com> Cc: Timur Tabi <timur@freescale.com> Signed-off-by: Qiang Liu <qiang.liu@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
| |