From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from va3outboundpool.messaging.microsoft.com (va3ehsobe006.messaging.microsoft.com [216.32.180.16]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (Client CN "mail.global.frontbridge.com", Issuer "Microsoft Secure Server Authority" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 4DD002C072A for ; Fri, 27 Jul 2012 19:17:14 +1000 (EST) From: To: , Subject: [PATCH v4 5/7] fsl-dma: use spin_lock_bh to instead of spin_lock_irqsave Date: Fri, 27 Jul 2012 17:16:38 +0800 Message-ID: <1343380598-12071-1-git-send-email-qiang.liu@freescale.com> MIME-Version: 1.0 Content-Type: text/plain Cc: Vinod Koul , Timur Tabi , Qiang Liu , herbert@gondor.hengli.com.au, Dan Williams , davem@davemloft.net List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Qiang Liu - 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 Cc: Vinod Koul Cc: Li Yang Cc: Timur Tabi Signed-off-by: Qiang Liu --- 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