[PATCH] dmaengine: xilinx_vdma: Fix issues with non-parking mode
Vinod Koul
vinod.koul at intel.com
Sun Feb 21 20:46:53 PST 2016
On Tue, Feb 16, 2016 at 02:59:06PM +0530, Kedareswara rao Appana wrote:
> This patch fixes issues with the Non-parking mode(Cirular mode).
> With the existing driver in cirular mode if we submit frames less than h/w
> configured we simply end-up having misconfigured vdma h/w.
> This patch fixes this issue by
> ----> By queing multiple descripotrs.
> ----> By configuring the frame count register.
And quick look seems like too many changes in one patch.
>
> Signed-off-by: Kedareswara rao Appana <appanad at xilinx.com>
> ---
> drivers/dma/xilinx/xilinx_vdma.c | 193 ++++++++++++++++++---------------------
> 1 file changed, 91 insertions(+), 102 deletions(-)
>
> diff --git a/drivers/dma/xilinx/xilinx_vdma.c b/drivers/dma/xilinx/xilinx_vdma.c
> index 6f4b501..a73c8e1 100644
> --- a/drivers/dma/xilinx/xilinx_vdma.c
> +++ b/drivers/dma/xilinx/xilinx_vdma.c
> @@ -190,8 +190,7 @@ struct xilinx_vdma_tx_descriptor {
> * @desc_offset: TX descriptor registers offset
> * @lock: Descriptor operation lock
> * @pending_list: Descriptors waiting
> - * @active_desc: Active descriptor
> - * @allocated_desc: Allocated descriptor
> + * @active_list: Descriptors ready to submit
Which should probably be a separate patch describing why list management is
changed?
So can you please split up with right changelogs and resend
Thanks
--
~Vinod
> * @done_list: Complete descriptors
> * @common: DMA common channel
> * @desc_pool: Descriptors pool
> @@ -203,9 +202,11 @@ struct xilinx_vdma_tx_descriptor {
> * @has_sg: Support scatter transfers
> * @genlock: Support genlock mode
> * @err: Channel has errors
> + * @idle: Check for channel idle
> * @tasklet: Cleanup work after irq
> * @config: Device configuration info
> * @flush_on_fsync: Flush on Frame sync
> + * @desc_pendingcount: Descriptor pending count
> */
> struct xilinx_vdma_chan {
> struct xilinx_vdma_device *xdev;
> @@ -213,8 +214,7 @@ struct xilinx_vdma_chan {
> u32 desc_offset;
> spinlock_t lock;
> struct list_head pending_list;
> - struct xilinx_vdma_tx_descriptor *active_desc;
> - struct xilinx_vdma_tx_descriptor *allocated_desc;
> + struct list_head active_list;
> struct list_head done_list;
> struct dma_chan common;
> struct dma_pool *desc_pool;
> @@ -226,9 +226,11 @@ struct xilinx_vdma_chan {
> bool has_sg;
> bool genlock;
> bool err;
> + bool idle;
> struct tasklet_struct tasklet;
> struct xilinx_vdma_config config;
> bool flush_on_fsync;
> + u32 desc_pendingcount;
> };
>
> /**
> @@ -342,19 +344,11 @@ static struct xilinx_vdma_tx_descriptor *
> xilinx_vdma_alloc_tx_descriptor(struct xilinx_vdma_chan *chan)
> {
> struct xilinx_vdma_tx_descriptor *desc;
> - unsigned long flags;
> -
> - if (chan->allocated_desc)
> - return chan->allocated_desc;
>
> desc = kzalloc(sizeof(*desc), GFP_KERNEL);
> if (!desc)
> return NULL;
>
> - spin_lock_irqsave(&chan->lock, flags);
> - chan->allocated_desc = desc;
> - spin_unlock_irqrestore(&chan->lock, flags);
> -
> INIT_LIST_HEAD(&desc->segments);
>
> return desc;
> @@ -412,9 +406,7 @@ static void xilinx_vdma_free_descriptors(struct xilinx_vdma_chan *chan)
>
> xilinx_vdma_free_desc_list(chan, &chan->pending_list);
> xilinx_vdma_free_desc_list(chan, &chan->done_list);
> -
> - xilinx_vdma_free_tx_descriptor(chan, chan->active_desc);
> - chan->active_desc = NULL;
> + xilinx_vdma_free_desc_list(chan, &chan->active_list);
>
> spin_unlock_irqrestore(&chan->lock, flags);
> }
> @@ -529,32 +521,6 @@ static enum dma_status xilinx_vdma_tx_status(struct dma_chan *dchan,
> }
>
> /**
> - * xilinx_vdma_is_running - Check if VDMA channel is running
> - * @chan: Driver specific VDMA channel
> - *
> - * Return: '1' if running, '0' if not.
> - */
> -static bool xilinx_vdma_is_running(struct xilinx_vdma_chan *chan)
> -{
> - return !(vdma_ctrl_read(chan, XILINX_VDMA_REG_DMASR) &
> - XILINX_VDMA_DMASR_HALTED) &&
> - (vdma_ctrl_read(chan, XILINX_VDMA_REG_DMACR) &
> - XILINX_VDMA_DMACR_RUNSTOP);
> -}
> -
> -/**
> - * xilinx_vdma_is_idle - Check if VDMA channel is idle
> - * @chan: Driver specific VDMA channel
> - *
> - * Return: '1' if idle, '0' if not.
> - */
> -static bool xilinx_vdma_is_idle(struct xilinx_vdma_chan *chan)
> -{
> - return vdma_ctrl_read(chan, XILINX_VDMA_REG_DMASR) &
> - XILINX_VDMA_DMASR_IDLE;
> -}
> -
> -/**
> * xilinx_vdma_halt - Halt VDMA channel
> * @chan: Driver specific VDMA channel
> */
> @@ -614,45 +580,34 @@ static void xilinx_vdma_start(struct xilinx_vdma_chan *chan)
> static void xilinx_vdma_start_transfer(struct xilinx_vdma_chan *chan)
> {
> struct xilinx_vdma_config *config = &chan->config;
> - struct xilinx_vdma_tx_descriptor *desc;
> - unsigned long flags;
> + struct xilinx_vdma_tx_descriptor *desc, *tail_desc;
> u32 reg;
> - struct xilinx_vdma_tx_segment *head, *tail = NULL;
> + struct xilinx_vdma_tx_segment *tail_segment;
>
> if (chan->err)
> return;
>
> - spin_lock_irqsave(&chan->lock, flags);
> -
> - /* There's already an active descriptor, bail out. */
> - if (chan->active_desc)
> - goto out_unlock;
> -
> if (list_empty(&chan->pending_list))
> - goto out_unlock;
> + return;
> +
> + if (!chan->idle)
> + return;
>
> desc = list_first_entry(&chan->pending_list,
> struct xilinx_vdma_tx_descriptor, node);
> + tail_desc = list_last_entry(&chan->pending_list,
> + struct xilinx_vdma_tx_descriptor, node);
>
> - /* If it is SG mode and hardware is busy, cannot submit */
> - if (chan->has_sg && xilinx_vdma_is_running(chan) &&
> - !xilinx_vdma_is_idle(chan)) {
> - dev_dbg(chan->dev, "DMA controller still busy\n");
> - goto out_unlock;
> - }
> + tail_segment = list_last_entry(&tail_desc->segments,
> + struct xilinx_vdma_tx_segment, node);
>
> /*
> * If hardware is idle, then all descriptors on the running lists are
> * done, start new transfers
> */
> - if (chan->has_sg) {
> - head = list_first_entry(&desc->segments,
> - struct xilinx_vdma_tx_segment, node);
> - tail = list_entry(desc->segments.prev,
> - struct xilinx_vdma_tx_segment, node);
> -
> - vdma_ctrl_write(chan, XILINX_VDMA_REG_CURDESC, head->phys);
> - }
> + if (chan->has_sg)
> + vdma_ctrl_write(chan, XILINX_VDMA_REG_CURDESC,
> + desc->async_tx.phys);
>
> /* Configure the hardware using info in the config structure */
> reg = vdma_ctrl_read(chan, XILINX_VDMA_REG_DMACR);
> @@ -662,6 +617,9 @@ static void xilinx_vdma_start_transfer(struct xilinx_vdma_chan *chan)
> else
> reg &= ~XILINX_VDMA_DMACR_FRAMECNT_EN;
>
> + vdma_ctrl_write(chan, XILINX_VDMA_REG_FRMSTORE,
> + chan->desc_pendingcount);
> +
> /*
> * With SG, start with circular mode, so that BDs can be fetched.
> * In direct register mode, if not parking, enable circular mode
> @@ -690,16 +648,19 @@ static void xilinx_vdma_start_transfer(struct xilinx_vdma_chan *chan)
> xilinx_vdma_start(chan);
>
> if (chan->err)
> - goto out_unlock;
> + return;
>
> /* Start the transfer */
> if (chan->has_sg) {
> - vdma_ctrl_write(chan, XILINX_VDMA_REG_TAILDESC, tail->phys);
> + vdma_ctrl_write(chan, XILINX_VDMA_REG_TAILDESC,
> + tail_segment->phys);
> } else {
> struct xilinx_vdma_tx_segment *segment, *last = NULL;
> int i = 0;
>
> - list_for_each_entry(segment, &desc->segments, node) {
> + list_for_each_entry(desc, &chan->pending_list, node) {
> + segment = list_first_entry(&desc->segments,
> + struct xilinx_vdma_tx_segment, node);
> vdma_desc_write(chan,
> XILINX_VDMA_REG_START_ADDRESS(i++),
> segment->hw.buf_addr);
> @@ -707,7 +668,7 @@ static void xilinx_vdma_start_transfer(struct xilinx_vdma_chan *chan)
> }
>
> if (!last)
> - goto out_unlock;
> + return;
>
> /* HW expects these parameters to be same for one transaction */
> vdma_desc_write(chan, XILINX_VDMA_REG_HSIZE, last->hw.hsize);
> @@ -716,11 +677,9 @@ static void xilinx_vdma_start_transfer(struct xilinx_vdma_chan *chan)
> vdma_desc_write(chan, XILINX_VDMA_REG_VSIZE, last->hw.vsize);
> }
>
> - list_del(&desc->node);
> - chan->active_desc = desc;
> -
> -out_unlock:
> - spin_unlock_irqrestore(&chan->lock, flags);
> + list_splice_tail_init(&chan->pending_list, &chan->active_list);
> + chan->desc_pendingcount = 0;
> + chan->idle = false;
> }
>
> /**
> @@ -730,8 +689,11 @@ out_unlock:
> static void xilinx_vdma_issue_pending(struct dma_chan *dchan)
> {
> struct xilinx_vdma_chan *chan = to_xilinx_chan(dchan);
> + unsigned long flags;
>
> + spin_lock_irqsave(&chan->lock, flags);
> xilinx_vdma_start_transfer(chan);
> + spin_unlock_irqrestore(&chan->lock, flags);
> }
>
> /**
> @@ -742,24 +704,16 @@ static void xilinx_vdma_issue_pending(struct dma_chan *dchan)
> */
> static void xilinx_vdma_complete_descriptor(struct xilinx_vdma_chan *chan)
> {
> - struct xilinx_vdma_tx_descriptor *desc;
> - unsigned long flags;
> + struct xilinx_vdma_tx_descriptor *desc, *next;
>
> - spin_lock_irqsave(&chan->lock, flags);
> + if (list_empty(&chan->active_list))
> + return;
>
> - desc = chan->active_desc;
> - if (!desc) {
> - dev_dbg(chan->dev, "no running descriptors\n");
> - goto out_unlock;
> + list_for_each_entry_safe(desc, next, &chan->active_list, node) {
> + list_del(&desc->node);
> + dma_cookie_complete(&desc->async_tx);
> + list_add_tail(&desc->node, &chan->done_list);
> }
> -
> - dma_cookie_complete(&desc->async_tx);
> - list_add_tail(&desc->node, &chan->done_list);
> -
> - chan->active_desc = NULL;
> -
> -out_unlock:
> - spin_unlock_irqrestore(&chan->lock, flags);
> }
>
> /**
> @@ -870,8 +824,11 @@ static irqreturn_t xilinx_vdma_irq_handler(int irq, void *data)
> }
>
> if (status & XILINX_VDMA_DMASR_FRM_CNT_IRQ) {
> + spin_lock(&chan->lock);
> xilinx_vdma_complete_descriptor(chan);
> + chan->idle = true;
> xilinx_vdma_start_transfer(chan);
> + spin_unlock(&chan->lock);
> }
>
> tasklet_schedule(&chan->tasklet);
> @@ -879,6 +836,45 @@ static irqreturn_t xilinx_vdma_irq_handler(int irq, void *data)
> }
>
> /**
> + * append_desc_queue - Queuing descriptor
> + * @chan: Driver specific dma channel
> + * @desc: dma transaction descriptor
> + */
> +static void append_desc_queue(struct xilinx_vdma_chan *chan,
> + struct xilinx_vdma_tx_descriptor *desc)
> +{
> + struct xilinx_vdma_tx_segment *tail_segment;
> + struct xilinx_vdma_tx_descriptor *tail_desc;
> +
> + if (list_empty(&chan->pending_list))
> + goto append;
> +
> + /*
> + * Add the hardware descriptor to the chain of hardware descriptors
> + * that already exists in memory.
> + */
> + tail_desc = list_last_entry(&chan->pending_list,
> + struct xilinx_vdma_tx_descriptor, node);
> + tail_segment = list_last_entry(&tail_desc->segments,
> + struct xilinx_vdma_tx_segment, node);
> + tail_segment->hw.next_desc = (u32)desc->async_tx.phys;
> +
> + /*
> + * Add the software descriptor and all children to the list
> + * of pending transactions
> + */
> +append:
> + list_add_tail(&desc->node, &chan->pending_list);
> + chan->desc_pendingcount++;
> +
> + if (unlikely(chan->desc_pendingcount > chan->num_frms)) {
> + dev_dbg(chan->dev, "desc pendingcount is too high\n");
> + chan->desc_pendingcount = chan->num_frms;
> + BUG();
> + }
> +}
> +
> +/**
> * xilinx_vdma_tx_submit - Submit DMA transaction
> * @tx: Async transaction descriptor
> *
> @@ -906,11 +902,8 @@ static dma_cookie_t xilinx_vdma_tx_submit(struct dma_async_tx_descriptor *tx)
>
> cookie = dma_cookie_assign(tx);
>
> - /* Append the transaction to the pending transactions queue. */
> - list_add_tail(&desc->node, &chan->pending_list);
> -
> - /* Free the allocated desc */
> - chan->allocated_desc = NULL;
> + /* Put this transaction onto the tail of the pending queue */
> + append_desc_queue(chan, desc);
>
> spin_unlock_irqrestore(&chan->lock, flags);
>
> @@ -973,13 +966,6 @@ xilinx_vdma_dma_prep_interleaved(struct dma_chan *dchan,
> else
> hw->buf_addr = xt->src_start;
>
> - /* Link the previous next descriptor to current */
> - if (!list_empty(&desc->segments)) {
> - prev = list_last_entry(&desc->segments,
> - struct xilinx_vdma_tx_segment, node);
> - prev->hw.next_desc = segment->phys;
> - }
> -
> /* Insert the segment into the descriptor segments list. */
> list_add_tail(&segment->node, &desc->segments);
>
> @@ -988,7 +974,7 @@ xilinx_vdma_dma_prep_interleaved(struct dma_chan *dchan,
> /* Link the last hardware descriptor with the first. */
> segment = list_first_entry(&desc->segments,
> struct xilinx_vdma_tx_segment, node);
> - prev->hw.next_desc = segment->phys;
> + desc->async_tx.phys = segment->phys;
>
> return &desc->async_tx;
>
> @@ -1127,10 +1113,12 @@ static int xilinx_vdma_chan_probe(struct xilinx_vdma_device *xdev,
> chan->dev = xdev->dev;
> chan->xdev = xdev;
> chan->has_sg = xdev->has_sg;
> + chan->desc_pendingcount = 0x0;
>
> spin_lock_init(&chan->lock);
> INIT_LIST_HEAD(&chan->pending_list);
> INIT_LIST_HEAD(&chan->done_list);
> + INIT_LIST_HEAD(&chan->active_list);
>
> /* Retrieve the channel properties from the device tree */
> has_dre = of_property_read_bool(node, "xlnx,include-dre");
> @@ -1198,6 +1186,7 @@ static int xilinx_vdma_chan_probe(struct xilinx_vdma_device *xdev,
>
> list_add_tail(&chan->common.device_node, &xdev->common.channels);
> xdev->chan[chan->id] = chan;
> + chan->idle = true;
>
> /* Reset the channel */
> err = xilinx_vdma_chan_reset(chan);
> --
> 2.1.2
>
More information about the linux-arm-kernel
mailing list