Re: [PATCH v2 3/4] can: flexcan: switch on clocks before accessing ecr register

From: Marc Kleine-Budde
Date: Mon Jul 14 2014 - 08:14:49 EST

On 07/14/2014 09:48 AM, Stefan Agner wrote:
> Reported-by: Ashutosh Singh <ashuleapyear@xxxxxxxxx>
> Suggested-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
> [stefan@xxxxxxxx: added return check for clk_enable_prepare]
>
> Signed-off-by: Stefan Agner <stefan@xxxxxxxx>
> ---
> drivers/net/can/flexcan.c | 16 +++++++++++++++-
> 1 file changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
> index f425ec2..4c598c9 100644
> --- a/drivers/net/can/flexcan.c
> +++ b/drivers/net/can/flexcan.c
> @@ -383,11 +383,25 @@ static int flexcan_get_berr_counter(const struct net_device *dev,
> {
> const struct flexcan_priv *priv = netdev_priv(dev);
> struct flexcan_regs __iomem *regs = priv->base;
> - u32 reg = flexcan_read(&regs->ecr);
> + u32 reg, err;
> +
> + err = clk_prepare_enable(priv->clk_ipg);
> + if (err)
> + return err;
> +
> + err = clk_prepare_enable(priv->clk_per);
> + if (err)
> + goto out_disable_ipg;
> +
> + reg = flexcan_read(&regs->ecr);
>
> bec->txerr = (reg >> 0) & 0xff;
> bec->rxerr = (reg >> 8) & 0xff;
>
> + clk_disable_unprepare(priv->clk_per);
> + out_disable_ipg:
> + clk_disable_unprepare(priv->clk_ipg);
> +
> return 0;

You should return an error in case of an error.

Marc

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