linux-kernel - Re: [PATCH] serial: sh-sci: don't filter on DMA device, use only channel ID

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Message-ID: <1308916071.1536.4.camel@vkoul-udesk3>
Date:	Fri, 24 Jun 2011 17:17:51 +0530
From:	"Koul, Vinod" <vinod.koul@...el.com>
To:	Guennadi Liakhovetski <g.liakhovetski@....de>
Cc:	linux-sh@...r.kernel.org, linux-kernel@...r.kernel.org,
	Dan Williams <dan.j.williams@...el.com>,
	Magnus Damm <damm@...nsource.se>
Subject: Re: [PATCH] serial: sh-sci: don't filter on DMA device, use only
 channel ID

On Fri, 2011-06-24 at 13:56 +0200, Guennadi Liakhovetski wrote:
> On some sh-mobile systems there are more than one DMA controllers, that
> can be used for serial ports. Specifying a DMA device in sh-sci platform
> data unnecessarily restricts the driver to only use one DMA controller.
> 
> Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@....de>
> ---
>  drivers/tty/serial/sh-sci.c |   25 ++++++++-----------------
>  include/linux/serial_sci.h  |    2 --
>  2 files changed, 8 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
> index ebd8629..8711f4e 100644
> --- a/drivers/tty/serial/sh-sci.c
> +++ b/drivers/tty/serial/sh-sci.c
> @@ -1295,12 +1295,8 @@ static bool filter(struct dma_chan *chan, void *slave)
>  	dev_dbg(chan->device->dev, "%s: slave ID %d\n", __func__,
>  		param->slave_id);
>  
> -	if (param->dma_dev == chan->device->dev) {
> -		chan->private = param;
> -		return true;
> -	} else {
> -		return false;
> -	}
> +	chan->private = param;
> +	return true;
You should not assign chan->private. 
Please move this  to dma_slave_control API
>  }
>  
>  static void rx_timer_fn(unsigned long arg)
> @@ -1326,10 +1322,10 @@ static void sci_request_dma(struct uart_port *port)
>  	dma_cap_mask_t mask;
>  	int nent;
>  
> -	dev_dbg(port->dev, "%s: port %d DMA %p\n", __func__,
> -		port->line, s->cfg->dma_dev);
> +	dev_dbg(port->dev, "%s: port %d\n", __func__,
> +		port->line);
>  
> -	if (!s->cfg->dma_dev)
> +	if (s->cfg->dma_slave_tx <= 0 || s->cfg->dma_slave_rx <= 0)
>  		return;
>  
>  	dma_cap_zero(mask);
> @@ -1339,7 +1335,6 @@ static void sci_request_dma(struct uart_port *port)
>  
>  	/* Slave ID, e.g., SHDMA_SLAVE_SCIF0_TX */
>  	param->slave_id = s->cfg->dma_slave_tx;
> -	param->dma_dev = s->cfg->dma_dev;
>  
>  	s->cookie_tx = -EINVAL;
>  	chan = dma_request_channel(mask, filter, param);
> @@ -1368,7 +1363,6 @@ static void sci_request_dma(struct uart_port *port)
>  
>  	/* Slave ID, e.g., SHDMA_SLAVE_SCIF0_RX */
>  	param->slave_id = s->cfg->dma_slave_rx;
> -	param->dma_dev = s->cfg->dma_dev;
>  
>  	chan = dma_request_channel(mask, filter, param);
>  	dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
> @@ -1413,9 +1407,6 @@ static void sci_free_dma(struct uart_port *port)
>  {
>  	struct sci_port *s = to_sci_port(port);
>  
> -	if (!s->cfg->dma_dev)
> -		return;
> -
>  	if (s->chan_tx)
>  		sci_tx_dma_release(s, false);
>  	if (s->chan_rx)
> @@ -1790,9 +1781,9 @@ static int __devinit sci_init_single(struct platform_device *dev,
>  	 */
>  	port->irq		= p->irqs[SCIx_RXI_IRQ];
>  
> -	if (p->dma_dev)
> -		dev_dbg(port->dev, "DMA device %p, tx %d, rx %d\n",
> -			p->dma_dev, p->dma_slave_tx, p->dma_slave_rx);
> +	if (p->dma_slave_tx > 0 && p->dma_slave_rx > 0)
> +		dev_dbg(port->dev, "DMA tx %d, rx %d\n",
> +			p->dma_slave_tx, p->dma_slave_rx);
>  
>  	return 0;
>  }
> diff --git a/include/linux/serial_sci.h b/include/linux/serial_sci.h
> index a2afc9f..9d01ffa 100644
> --- a/include/linux/serial_sci.h
> +++ b/include/linux/serial_sci.h
> @@ -56,8 +56,6 @@ struct plat_sci_port {
>  	unsigned int	scbrr_algo_id;		/* SCBRR calculation algo */
>  	unsigned int	scscr;			/* SCSCR initialization */
>  
> -	struct device	*dma_dev;
> -
>  	unsigned int	dma_slave_tx;
>  	unsigned int	dma_slave_rx;
>  };


-- 
~Vinod

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