From mboxrd@z Thu Jan 1 00:00:00 1970 From: LW@KARO-electronics.de (Lothar =?UTF-8?B?V2HDn21hbm4=?=) Date: Tue, 15 Jul 2014 15:54:26 +0200 Subject: [PATCH v3 3/4] can: flexcan: switch on clocks before accessing ecr register In-Reply-To: References: Message-ID: <20140715155426.3c03f0d8@ipc1.ka-ro> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi, Stefan Agner wrote: > Reported-by: Ashutosh Singh > Suggested-by: Marc Kleine-Budde > [stefan at agner.ch: added return check for clk_enable_prepare] > > Signed-off-by: Stefan Agner > --- > drivers/net/can/flexcan.c | 18 ++++++++++++++++-- > 1 file changed, 16 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c > index f425ec2..89745aa 100644 > --- a/drivers/net/can/flexcan.c > +++ b/drivers/net/can/flexcan.c > @@ -383,12 +383,26 @@ 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(®s->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(®s->ecr); > flexcan_get_berr_counter() may be called from interrupt context and thus must not call any functions that can sleep. Compiling the driver with CONFIG_DEBUG_ATOMIC_SLEEP would catch this! Lothar Wa?mann -- ___________________________________________________________ Ka-Ro electronics GmbH | Pascalstra?e 22 | D - 52076 Aachen Phone: +49 2408 1402-0 | Fax: +49 2408 1402-10 Gesch?ftsf?hrer: Matthias Kaussen Handelsregistereintrag: Amtsgericht Aachen, HRB 4996 www.karo-electronics.de | info at karo-electronics.de ___________________________________________________________