Re: [PATCH v5 4/6] fsl-dma: move the function ahead of its invokefunction

From: Ira W. Snyder
Date: Wed Aug 01 2012 - 12:40:34 EST


On Wed, Aug 01, 2012 at 04:49:43PM +0800, qiang.liu@xxxxxxxxxxxxx wrote:
> From: Qiang Liu <qiang.liu@xxxxxxxxxxxxx>
>
> Move the function fsldma_cleanup_descriptor() and fsl_chan_xfer_ld_queue()
> ahead of its invoke function for avoiding redundant definition.
>
> Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
> Cc: Vinod Koul <vinod.koul@xxxxxxxxx>
> Cc: Li Yang <leoli@xxxxxxxxxxxxx>
> Signed-off-by: Qiang Liu <qiang.liu@xxxxxxxxxxxxx>
> ---
> drivers/dma/fsldma.c | 252 +++++++++++++++++++++++++-------------------------
> 1 files changed, 124 insertions(+), 128 deletions(-)
>
> diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c
> index 87f52c0..bb883c0 100644
> --- a/drivers/dma/fsldma.c
> +++ b/drivers/dma/fsldma.c
> @@ -400,9 +400,6 @@ out_splice:
> list_splice_tail_init(&desc->tx_list, &chan->ld_pending);
> }
>
> -static void fsldma_cleanup_descriptor(struct fsldma_chan *chan);
> -static void fsl_chan_xfer_ld_queue(struct fsldma_chan *chan);
> -

Please swap the order of this patch (patch 4/6) and the previous patch
(patch 3/6).

You added these lines in the patch 3/6 and deleted them here. If you
reverse the order of the patches, this doesn't happen.

Adding lines only to delete them in the next patch should be avoided.

> /**
> * fsldma_clean_completed_descriptor - free all descriptors which
> * has been completed and acked
> @@ -519,6 +516,130 @@ fsldma_clean_running_descriptor(struct fsldma_chan *chan,
> return 0;
> }
>
> +/**
> + * fsl_chan_xfer_ld_queue - transfer any pending transactions
> + * @chan : Freescale DMA channel
> + *
> + * HARDWARE STATE: idle
> + * LOCKING: must hold chan->desc_lock
> + */
> +static void fsl_chan_xfer_ld_queue(struct fsldma_chan *chan)
> +{
> + struct fsl_desc_sw *desc;
> +
> + /*
> + * If the list of pending descriptors is empty, then we
> + * don't need to do any work at all
> + */
> + if (list_empty(&chan->ld_pending)) {
> + chan_dbg(chan, "no pending LDs\n");
> + return;
> + }
> +
> + /*
> + * The DMA controller is not idle, which means that the interrupt
> + * handler will start any queued transactions when it runs after
> + * this transaction finishes
> + */
> + if (!chan->idle) {
> + chan_dbg(chan, "DMA controller still busy\n");
> + return;
> + }
> +
> + /*
> + * If there are some link descriptors which have not been
> + * transferred, we need to start the controller
> + */
> +
> + /*
> + * Move all elements from the queue of pending transactions
> + * onto the list of running transactions
> + */
> + chan_dbg(chan, "idle, starting controller\n");
> + desc = list_first_entry(&chan->ld_pending, struct fsl_desc_sw, node);
> + list_splice_tail_init(&chan->ld_pending, &chan->ld_running);
> +
> + /*
> + * The 85xx DMA controller doesn't clear the channel start bit
> + * automatically at the end of a transfer. Therefore we must clear
> + * it in software before starting the transfer.
> + */
> + if ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) {
> + u32 mode;
> +
> + mode = DMA_IN(chan, &chan->regs->mr, 32);
> + mode &= ~FSL_DMA_MR_CS;
> + DMA_OUT(chan, &chan->regs->mr, mode, 32);
> + }
> +
> + /*
> + * Program the descriptor's address into the DMA controller,
> + * then start the DMA transaction
> + */
> + set_cdar(chan, desc->async_tx.phys);
> + get_cdar(chan);
> +
> + dma_start(chan);
> + chan->idle = false;
> +}
> +
> +/**
> + * fsldma_cleanup_descriptor - cleanup and free a single link descriptor
> + * @chan: Freescale DMA channel
> + * @desc: descriptor to cleanup and free
> + *
> + * This function is used on a descriptor which has been executed by the DMA
> + * controller. It will run any callbacks, submit any dependencies, and then
> + * free the descriptor.
> + */
> +static void fsldma_cleanup_descriptor(struct fsldma_chan *chan)
> +{
> + struct fsl_desc_sw *desc, *_desc;
> + dma_cookie_t cookie = 0;
> + dma_addr_t curr_phys = get_cdar(chan);
> + int idle = dma_is_idle(chan);
> + int seen_current = 0;
> +
> + fsldma_clean_completed_descriptor(chan);
> +
> + /* Run the callback for each descriptor, in order */
> + list_for_each_entry_safe(desc, _desc, &chan->ld_running, node) {
> + /*
> + * do not advance past the current descriptor loaded into the
> + * hardware channel, subsequent descriptors are either in
> + * process or have not been submitted
> + */
> + if (seen_current)
> + break;
> +
> + /*
> + * stop the search if we reach the current descriptor and the
> + * channel is busy
> + */
> + if (desc->async_tx.phys == curr_phys) {
> + seen_current = 1;
> + if (!idle)
> + break;
> + }
> +
> + cookie = fsldma_run_tx_complete_actions(desc, chan, cookie);
> +
> + if (fsldma_clean_running_descriptor(chan, desc))
> + break;
> + }
> +
> + /*
> + * Start any pending transactions automatically
> + *
> + * In the ideal case, we keep the DMA controller busy while we go
> + * ahead and free the descriptors below.
> + */
> + fsl_chan_xfer_ld_queue(chan);
> +
> + if (cookie > 0)
> + chan->common.completed_cookie = cookie;
> +}
> +
> static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx)
> {
> struct fsldma_chan *chan = to_fsl_chan(tx->chan);
> @@ -932,131 +1053,6 @@ static int fsl_dma_device_control(struct dma_chan *dchan,
> }
>
> /**
> - * fsldma_cleanup_descriptor - cleanup and free a single link descriptor
> - * @chan: Freescale DMA channel
> - * @desc: descriptor to cleanup and free
> - *
> - * This function is used on a descriptor which has been executed by the DMA
> - * controller. It will run any callbacks, submit any dependencies, and then
> - * free the descriptor.
> - */
> -static void fsldma_cleanup_descriptor(struct fsldma_chan *chan)
> -{
> - struct fsl_desc_sw *desc, *_desc;
> - dma_cookie_t cookie = 0;
> - dma_addr_t curr_phys = get_cdar(chan);
> - int idle = dma_is_idle(chan);
> - int seen_current = 0;
> -
> - fsldma_clean_completed_descriptor(chan);
> -
> - /* Run the callback for each descriptor, in order */
> - list_for_each_entry_safe(desc, _desc, &chan->ld_running, node) {
> - /*
> - * do not advance past the current descriptor loaded into the
> - * hardware channel, subsequent descriptors are either in
> - * process or have not been submitted
> - */
> - if (seen_current)
> - break;
> -
> - /*
> - * stop the search if we reach the current descriptor and the
> - * channel is busy
> - */
> - if (desc->async_tx.phys == curr_phys) {
> - seen_current = 1;
> - if (!idle)
> - break;
> - }
> -
> - cookie = fsldma_run_tx_complete_actions(desc, chan, cookie);
> -
> - if (fsldma_clean_running_descriptor(chan, desc))
> - break;
> -
> - }
> -
> - /*
> - * Start any pending transactions automatically
> - *
> - * In the ideal case, we keep the DMA controller busy while we go
> - * ahead and free the descriptors below.
> - */
> - fsl_chan_xfer_ld_queue(chan);
> -
> - if (cookie > 0)
> - chan->common.completed_cookie = cookie;
> -}
> -
> -/**
> - * fsl_chan_xfer_ld_queue - transfer any pending transactions
> - * @chan : Freescale DMA channel
> - *
> - * HARDWARE STATE: idle
> - * LOCKING: must hold chan->desc_lock
> - */
> -static void fsl_chan_xfer_ld_queue(struct fsldma_chan *chan)
> -{
> - struct fsl_desc_sw *desc;
> -
> - /*
> - * If the list of pending descriptors is empty, then we
> - * don't need to do any work at all
> - */
> - if (list_empty(&chan->ld_pending)) {
> - chan_dbg(chan, "no pending LDs\n");
> - return;
> - }
> -
> - /*
> - * The DMA controller is not idle, which means that the interrupt
> - * handler will start any queued transactions when it runs after
> - * this transaction finishes
> - */
> - if (!chan->idle) {
> - chan_dbg(chan, "DMA controller still busy\n");
> - return;
> - }
> -
> - /*
> - * If there are some link descriptors which have not been
> - * transferred, we need to start the controller
> - */
> -
> - /*
> - * Move all elements from the queue of pending transactions
> - * onto the list of running transactions
> - */
> - chan_dbg(chan, "idle, starting controller\n");
> - desc = list_first_entry(&chan->ld_pending, struct fsl_desc_sw, node);
> - list_splice_tail_init(&chan->ld_pending, &chan->ld_running);
> -
> - /*
> - * The 85xx DMA controller doesn't clear the channel start bit
> - * automatically at the end of a transfer. Therefore we must clear
> - * it in software before starting the transfer.
> - */
> - if ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) {
> - u32 mode;
> -
> - mode = DMA_IN(chan, &chan->regs->mr, 32);
> - mode &= ~FSL_DMA_MR_CS;
> - DMA_OUT(chan, &chan->regs->mr, mode, 32);
> - }
> -
> - /*
> - * Program the descriptor's address into the DMA controller,
> - * then start the DMA transaction
> - */
> - set_cdar(chan, desc->async_tx.phys);
> - get_cdar(chan);
> -
> - dma_start(chan);
> - chan->idle = false;
> -}
> -
> -/**
> * fsl_dma_memcpy_issue_pending - Issue the DMA start command
> * @chan : Freescale DMA channel
> */
> --
> 1.7.5.1
>
>
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