[PATCH 4.4 56/73] can: flexcan: fix resume function

Greg Kroah-Hartman
2016-09-28T09:29:08Z

From: Fabio Estevam <fabio.estevam@nxp.com>

commit 4de349e786a3a2d51bd02d56f3de151bbc3c3df9 upstream.

On a imx6ul-pico board the following error is seen during system suspend:

dpm_run_callback(): platform_pm_resume+0x0/0x54 returns -110
PM: Device 2090000.flexcan failed to resume: error -110

The reason for this suspend error is because when the CAN interface is not
active the clocks are disabled and then flexcan_chip_enable() will
always fail due to a timeout error.

In order to fix this issue, only call flexcan_chip_enable/disable()
when the CAN interface is active.

Based on a patch from Dong Aisheng in the NXP kernel.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/net/can/flexcan.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)

--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -1268,11 +1268,10 @@ static int __maybe_unused flexcan_suspen
struct flexcan_priv *priv = netdev_priv(dev);
int err;

- err = flexcan_chip_disable(priv);
- if (err)
- return err;
-
if (netif_running(dev)) {
+ err = flexcan_chip_disable(priv);
+ if (err)
+ return err;
netif_stop_queue(dev);
netif_device_detach(dev);
}
@@ -1285,13 +1284,17 @@ static int __maybe_unused flexcan_resume
{
struct net_device *dev = dev_get_drvdata(device);
struct flexcan_priv *priv = netdev_priv(dev);
+ int err;

priv->can.state = CAN_STATE_ERROR_ACTIVE;
if (netif_running(dev)) {
netif_device_attach(dev);
netif_start_queue(dev);
+ err = flexcan_chip_enable(priv);
+ if (err)
+ return err;
}
- return flexcan_chip_enable(priv);
+ return 0;
}

static SIMPLE_DEV_PM_OPS(flexcan_pm_ops, flexcan_suspend, flexcan_resume);