Hi all, Please ignore this one. Thanks.
> -----Original Message----- > From: Liu Qiang-B32616 > Sent: Monday, August 06, 2012 6:15 PM > To: [email protected]; [email protected]; > [email protected]; [email protected]; > [email protected]; [email protected] > Cc: Phillips Kim-R1AAHA; [email protected]; > [email protected]; [email protected]; [email protected]; Liu > Qiang-B32616; Li Yang-R58472; Tabi Timur-B04825 > Subject: [PATCH 6/8] fsl-dma: use spin_lock_bh to instead of > spin_lock_irqsave > > From: Qiang Liu <[email protected]> > > The use of spin_lock_irqsave() is a stronger locking mechanism than is > required throughout the driver. The minimum locking required should be > used instead. Interrupts will be turned off and context will be saved, > there is needless to use irqsave. > > Change all instances of spin_lock_irqsave() to spin_lock_bh(). > All manipulation of protected fields is done using tasklet context or > weaker, which makes spin_lock_bh() the correct choice. > > Cc: Dan Williams <[email protected]> > Cc: Dan Williams <[email protected]> > Cc: Vinod Koul <[email protected]> > Cc: Li Yang <[email protected]> > Cc: Timur Tabi <[email protected]> > Signed-off-by: Qiang Liu <[email protected]> > Acked-by: Ira W. Snyder <[email protected]> > --- > 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 938d8c1..3f809df 100644 > --- a/drivers/dma/fsldma.c > +++ b/drivers/dma/fsldma.c > @@ -405,10 +405,9 @@ 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 > @@ -421,7 +420,7 @@ 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; > } > @@ -761,15 +760,14 @@ 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_descriptors(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; > @@ -988,7 +986,6 @@ 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) > @@ -998,7 +995,7 @@ 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); > @@ -1009,7 +1006,7 @@ static int fsl_dma_device_control(struct dma_chan > *dchan, > fsldma_free_desc_list(chan, &chan->ld_completed); > chan->idle = true; > > - spin_unlock_irqrestore(&chan->desc_lock, flags); > + spin_unlock_bh(&chan->desc_lock); > return 0; > > case DMA_SLAVE_CONFIG: > @@ -1051,11 +1048,10 @@ 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); > } > > /** > @@ -1068,15 +1064,14 @@ 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_descriptors(chan); > - spin_unlock_irqrestore(&chan->desc_lock, flags); > + spin_unlock_bh(&chan->desc_lock); > > return dma_cookie_status(dchan, cookie, txstate); > } > @@ -1155,11 +1150,10 @@ 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; > @@ -1167,7 +1161,7 @@ static void dma_do_tasklet(unsigned long data) > /* Run all cleanup for descriptors which have been completed */ > fsldma_cleanup_descriptors(chan); > > - spin_unlock_irqrestore(&chan->desc_lock, flags); > + spin_unlock_bh(&chan->desc_lock); > > chan_dbg(chan, "tasklet exit\n"); > } > -- > 1.7.5.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
