[PATCH v3 3/4] can: flexcan: switch on clocks before accessing ecr register
From: mkl@pengutronix.de (Marc Kleine-Budde)
Date: 2014-07-15 13:58:00
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On 07/15/2014 03:54 PM, Lothar Wa?mann wrote:
Hi, Stefan Agner wrote:quoted
Reported-by: Ashutosh Singh <redacted> Suggested-by: Marc Kleine-Budde <mkl@pengutronix.de> [stefan at agner.ch: added return check for clk_enable_prepare] Signed-off-by: Stefan Agner <stefan@agner.ch> --- 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: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20140715/00bbeec8/attachment-0001.sig>