From ec56acfef2af184ca485ffeba16adbd56c110c94 Mon Sep 17 00:00:00 2001 From: Stefan Agner Date: Tue, 15 Jul 2014 14:56:20 +0200 Subject: [PATCH] can: flexcan: flexcan_get_berr_counter(): switch on clocks before accessing ecr register The funcion flexcan_get_berr_counter() may be called from userspace even if the interface is down, this the clocks are disabled. This patch switches on the clocks before accessing the ecr register. Reported-by: Ashutosh Singh Signed-off-by: Stefan Agner Signed-off-by: Marc Kleine-Budde --- drivers/net/can/flexcan.c | 30 +++++++++++++++++++++++++++--- 1 file changed, 27 insertions(+), 3 deletions(-) diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c index f425ec2c7839..6bfe24aefea0 100644 --- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c @@ -378,8 +378,9 @@ static int flexcan_chip_softreset(struct flexcan_priv *priv) return 0; } -static int flexcan_get_berr_counter(const struct net_device *dev, - struct can_berr_counter *bec) + +static int __flexcan_get_berr_counter(const struct net_device *dev, + struct can_berr_counter *bec) { const struct flexcan_priv *priv = netdev_priv(dev); struct flexcan_regs __iomem *regs = priv->base; @@ -391,6 +392,29 @@ static int flexcan_get_berr_counter(const struct net_device *dev, return 0; } +static int flexcan_get_berr_counter(const struct net_device *dev, + struct can_berr_counter *bec) +{ + const struct flexcan_priv *priv = netdev_priv(dev); + int 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; + + err = __flexcan_get_berr_counter(dev, bec); + + clk_disable_unprepare(priv->clk_per); + out_disable_ipg: + clk_disable_unprepare(priv->clk_ipg); + + return err; +} + static int flexcan_start_xmit(struct sk_buff *skb, struct net_device *dev) { const struct flexcan_priv *priv = netdev_priv(dev); @@ -503,7 +527,7 @@ static void do_state(struct net_device *dev, struct flexcan_priv *priv = netdev_priv(dev); struct can_berr_counter bec; - flexcan_get_berr_counter(dev, &bec); + __flexcan_get_berr_counter(dev, &bec); switch (priv->can.state) { case CAN_STATE_ERROR_ACTIVE: