[3.16.y-ckt stable] Patch "can: flexcan: Deferred on Regulator return EPROBE_DEFER" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    can: flexcan: Deferred on Regulator return EPROBE_DEFER

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt10.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 88772980d6b3278c1c24885bf0fdf8d149769824 Mon Sep 17 00:00:00 2001
From: Andreas Werner <kernel at andy89.org>
Date: Sun, 22 Mar 2015 17:35:52 +0100
Subject: can: flexcan: Deferred on Regulator return EPROBE_DEFER

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 at andy89.org>
Signed-off-by: Marc Kleine-Budde <mkl at pengutronix.de>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/net/can/flexcan.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 9fc6f2cc2ed2..bf83639888a9 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -1131,12 +1131,19 @@ static int flexcan_probe(struct platform_device *pdev)
 	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);
@@ -1198,9 +1205,7 @@ static int flexcan_probe(struct platform_device *pdev)
 	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);