[PATCH 3.19 067/101] can: flexcan: Deferred on Regulator return EPROBE_DEFER

Greg Kroah-Hartman
2015-04-17T13:36:53Z

From: Andreas Werner <kernel@andy89.org>

commit 555828ef45f825d6ee06559f0304163550eed380 upstream.

Return EPROBE_DEFER if Regulator returns EPROBE_DEFER

If the Flexcan driver is built into kernel and a regulator is used to
enable the CAN transceiver, the Flexcan driver may not use the regulator.

When initializing the Flexcan device with a regulator defined in the device
tree, but not initialized, the regulator subsystem returns EPROBE_DEFER, hence
the Flexcan init fails.

The solution for this is to return EPROBE_DEFER if regulator is not initialized
and wait until the regulator is initialized.

Signed-off-by: Andreas Werner <kernel@andy89.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/net/can/flexcan.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -1158,12 +1158,19 @@ static int flexcan_probe(struct platform
const struct flexcan_devtype_data *devtype_data;
struct net_device *dev;
struct flexcan_priv *priv;
+ struct regulator *reg_xceiver;
struct resource *mem;
struct clk *clk_ipg = NULL, *clk_per = NULL;
void __iomem *base;
int err, irq;
u32 clock_freq = 0;

+ reg_xceiver = devm_regulator_get(&pdev->dev, "xceiver");
+ if (PTR_ERR(reg_xceiver) == -EPROBE_DEFER)
+ return -EPROBE_DEFER;
+ else if (IS_ERR(reg_xceiver))
+ reg_xceiver = NULL;
+
if (pdev->dev.of_node)
of_property_read_u32(pdev->dev.of_node,
"clock-frequency", &clock_freq);
@@ -1225,9 +1232,7 @@ static int flexcan_probe(struct platform
priv->pdata = dev_get_platdata(&pdev->dev);
priv->devtype_data = devtype_data;

- priv->reg_xceiver = devm_regulator_get(&pdev->dev, "xceiver");
- if (IS_ERR(priv->reg_xceiver))
- priv->reg_xceiver = NULL;
+ priv->reg_xceiver = reg_xceiver;

netif_napi_add(dev, &priv->napi, flexcan_poll, FLEXCAN_NAPI_WEIGHT);