On Mon, Feb 22, 2016 at 11:24:37AM +0530, Kedareswara rao Appana wrote:
> This patch improves the channel idle cheking by introduing
^^^^^^^^^
typo
> a new varibale in chan private structure.
^^^^^^^
here too :(
and there is no description how this improvement is achieved and why
>
> Signed-off-by: Kedareswara rao Appana <appa...@xilinx.com>
> ---
> Changes for v2:
> ---> splitted the changes into multiple patches.
>
> drivers/dma/xilinx/xilinx_vdma.c | 41
> ++++++++--------------------------------
> 1 file changed, 8 insertions(+), 33 deletions(-)
>
> diff --git a/drivers/dma/xilinx/xilinx_vdma.c
> b/drivers/dma/xilinx/xilinx_vdma.c
> index 8db07f7..51686d1 100644
> --- a/drivers/dma/xilinx/xilinx_vdma.c
> +++ b/drivers/dma/xilinx/xilinx_vdma.c
> @@ -202,6 +202,7 @@ 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
> @@ -225,6 +226,7 @@ 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;
> @@ -519,32 +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
> */
> @@ -614,6 +590,9 @@ static void xilinx_vdma_start_transfer(struct
> xilinx_vdma_chan *chan)
> if (list_empty(&chan->pending_list))
> 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,
> @@ -622,13 +601,6 @@ static void xilinx_vdma_start_transfer(struct
> xilinx_vdma_chan *chan)
> tail_segment = list_last_entry(&tail_desc->segments,
> struct xilinx_vdma_tx_segment, 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");
> - return;
> - }
> -
> /*
> * If hardware is idle, then all descriptors on the running lists are
> * done, start new transfers
> @@ -708,6 +680,7 @@ static void xilinx_vdma_start_transfer(struct
> xilinx_vdma_chan *chan)
>
> list_splice_tail_init(&chan->pending_list, &chan->active_list);
> chan->desc_pendingcount = 0;
> + chan->idle = false;
> }
>
> /**
> @@ -854,6 +827,7 @@ 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);
> }
> @@ -1212,6 +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
>
--
~Vinod
