Re: [PATCH v2 1/2] flexcan: add err_irq handler for flexcan

[Marc Kleine-Budde <mkl@pengutronix.de>]

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On 06/20/2014 04:01 AM, Zhao Qiang wrote:
> when flexcan is not physically linked, command 'cantest' will
> trigger an err_irq, add err_irq handler for it.
> 
> Signed-off-by: Zhao Qiang <B45475@freescale.com>
> ---
> Changes for v2:
> 	- use a space instead of tab
> 	- use flexcan_poll_state instead of print
> 
>  drivers/net/can/flexcan.c | 31 ++++++++++++++++++++++++++++++-
>  1 file changed, 30 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
> index f425ec2..7432ba4 100644
> --- a/drivers/net/can/flexcan.c
> +++ b/drivers/net/can/flexcan.c
> @@ -208,6 +208,7 @@ struct flexcan_priv {
>  	void __iomem *base;
>  	u32 reg_esr;
>  	u32 reg_ctrl_default;
> +	unsigned int err_irq;
>  
>  	struct clk *clk_ipg;
>  	struct clk *clk_per;
> @@ -744,6 +745,23 @@ static irqreturn_t flexcan_irq(int irq, void *dev_id)
>  	return IRQ_HANDLED;
>  }
>  
> +static irqreturn_t flexcan_err_irq(int irq, void *dev_id)
> +{
> +	struct net_device *dev = dev_id;
> +	struct flexcan_priv *priv = netdev_priv(dev);
> +	struct flexcan_regs __iomem *regs = priv->base;
> +	u32 reg_ctrl, reg_esr;
> +
> +	reg_esr = flexcan_read(&regs->esr);
> +	reg_ctrl = flexcan_read(&regs->ctrl);
> +	if (reg_esr & FLEXCAN_ESR_TX_WRN) {

When is the err_irq triggered?

> +		flexcan_write(reg_esr & ~FLEXCAN_ESR_TX_WRN, &regs->esr);
> +		flexcan_write(reg_ctrl & ~FLEXCAN_CTRL_ERR_MSK, &regs->ctrl);
> +		flexcan_poll_state(dev, reg_esr);

poll_state() is does not work, if called from an IRQ
handler.....Depending when err_irq is triggered, is it worth to just
call the normal interrupt handler?

> +	}
> +	return IRQ_HANDLED;

Please return IRQ_HANDLED, only if there really was an interrupt.

> +}
> +
>  static void flexcan_set_bittiming(struct net_device *dev)
>  {
>  	const struct flexcan_priv *priv = netdev_priv(dev);
> @@ -944,6 +962,12 @@ static int flexcan_open(struct net_device *dev)
>  	if (err)
>  		goto out_close;
>  
> +	if (priv->err_irq)
> +		err = request_irq(priv->err_irq, flexcan_err_irq, IRQF_SHARED,
> +				  dev->name, dev);
> +	if (err)
> +		goto out_close;

In case of an error, you don't free() dev->irq.

> +
>  	/* start chip and queuing */
>  	err = flexcan_chip_start(dev);
>  	if (err)
> @@ -1099,7 +1123,7 @@ static int flexcan_probe(struct platform_device *pdev)
>  	struct resource *mem;
>  	struct clk *clk_ipg = NULL, *clk_per = NULL;
>  	void __iomem *base;
> -	int err, irq;
> +	int err, irq, err_irq;
>  	u32 clock_freq = 0;
>  
>  	if (pdev->dev.of_node)
> @@ -1126,6 +1150,10 @@ static int flexcan_probe(struct platform_device *pdev)
>  	if (irq <= 0)
>  		return -ENODEV;
>  
> +	err_irq = platform_get_irq(pdev, 1);
> +	if (err_irq <= 0)
> +		err_irq = 0;
> +
>  	base = devm_ioremap_resource(&pdev->dev, mem);
>  	if (IS_ERR(base))
>  		return PTR_ERR(base);
> @@ -1149,6 +1177,7 @@ static int flexcan_probe(struct platform_device *pdev)
>  	dev->flags |= IFF_ECHO;
>  
>  	priv = netdev_priv(dev);
> +	priv->err_irq = err_irq;
>  	priv->can.clock.freq = clock_freq;
>  	priv->can.bittiming_const = &flexcan_bittiming_const;
>  	priv->can.do_set_mode = flexcan_set_mode;
> 

Marc

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