From mboxrd@z Thu Jan 1 00:00:00 1970 From: mkl@pengutronix.de (Marc Kleine-Budde) Date: Tue, 15 Jul 2014 15:57:46 +0200 Subject: [PATCH v3 3/4] can: flexcan: switch on clocks before accessing ecr register In-Reply-To: <20140715155426.3c03f0d8@ipc1.ka-ro> References: <20140715155426.3c03f0d8@ipc1.ka-ro> Message-ID: <53C5335A.8000000@pengutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 07/15/2014 03:54 PM, Lothar Wa?mann wrote: > 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! It's called from the NAPI softirq. I'll prepare a patch. Marc -- Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de | -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 242 bytes Desc: OpenPGP digital signature URL: