[PATCH 6/9] dmaengine: consolidate tx_status functions

[H Hartley Sweeten]

On Tuesday, March 06, 2012 3:35 PM, Russell King wrote:
>
> Now that we have the completed cookie in the dma_chan structure, we
> can consolidate the tx_status functions by providing a function to set
> the txstate structure and returning the DMA status.  We also provide
> a separate helper to set the residue for cookies which are still in
> progress.
>
> Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
> ---

<snip>

>  drivers/dma/dmaengine.h     |   31 +++++++++++++++++++++++++++++++

<snip>

>  drivers/dma/ep93xx_dma.c    |    7 +------

<snip>

> diff --git a/drivers/dma/dmaengine.h b/drivers/dma/dmaengine.h
> index 47e0997..1ca5e0e 100644
> --- a/drivers/dma/dmaengine.h
> +++ b/drivers/dma/dmaengine.h
> @@ -45,4 +45,35 @@ static inline void dma_cookie_complete(struct dma_async_tx_descriptor *tx)
>  	tx->cookie = 0;
>  }
>  
> +/**
> + * dma_cookie_status - report cookie status
> + * @chan: dma channel
> + * @cookie: cookie we are interested in
> + * @state: dma_tx_state structure to return last/used cookies
> + *
> + * Report the status of the cookie, filling in the state structure if
> + * non-NULL.  No locking is required.
> + */
> +static inline enum dma_status dma_cookie_status(struct dma_chan *chan,
> +	dma_cookie_t cookie, struct dma_tx_state *state)
> +{
> +	dma_cookie_t used, complete;
> +
> +	used = chan->cookie;
> +	complete = chan->completed_cookie;
> +	barrier();
> +	if (state) {
> +		state->last = complete;
> +		state->used = used;
> +		state->residue = 0;
> +	}
> +	return dma_async_is_complete(cookie, complete, used);
> +}
> +
> +static inline void dma_set_residue(struct dma_tx_state *state, u32 residue)
> +{
> +	if (state)
> +		state->residue = residue;
> +}
> +
>  #endif

<snip>

> diff --git a/drivers/dma/ep93xx_dma.c b/drivers/dma/ep93xx_dma.c
> index 1c56f75..142ebf0 100644
> --- a/drivers/dma/ep93xx_dma.c
> +++ b/drivers/dma/ep93xx_dma.c
> @@ -1241,18 +1241,13 @@ static enum dma_status ep93xx_dma_tx_status(struct dma_chan *chan,
>  					    struct dma_tx_state *state)
>  {
>  	struct ep93xx_dma_chan *edmac = to_ep93xx_dma_chan(chan);
> -	dma_cookie_t last_used, last_completed;
>  	enum dma_status ret;
>  	unsigned long flags;
>  
>  	spin_lock_irqsave(&edmac->lock, flags);
> -	last_used = chan->cookie;
> -	last_completed = chan->completed_cookie;
> +	ret = dma_cookie_status(chan, cookie, state);
>  	spin_unlock_irqrestore(&edmac->lock, flags);
>  
> -	ret = dma_async_is_complete(cookie, last_completed, last_used);
> -	dma_set_tx_state(state, last_completed, last_used, 0);
> -
>  	return ret;
>  }
>  

For ep93xx:

Tested-by: H Hartley Sweeten <hsweeten at visionengravers.com>
Acked-by: H Hartley Sweeten <hsweeten at visionengravers.com>