From 2c8a5dcaa4143dfedf956a5349216ded3c3ad085 Mon Sep 17 00:00:00 2001 From: Matt Sealey Date: Mon, 21 Jan 2013 12:25:45 -0600 Subject: regulator: mc13892: sanity check num_regulators parsed vs. registered Imagine a situation where a device tree has a few regulators in an appropriate node: regulators { sw1 { .. }; vvideo { .. }; : vfake { .. }; vtypo { .. }; }; In the above example, the node name "vfake" is an attempt to match a regulator name inside the driver which just so happens to not exist. The node name "vtypo" represents an accidental typographical error in a regulator name which may have been introduced to a device tree. In these cases, the number of regulators the mc13892 driver thinks it has does not match the number of regulators it parsed and registered. Since it will go over this array based on this number, it will actually re-register regulator "0" (which happens to be SW1) over and over again until it reaches the number, resulting in messages on the kernel log such as these: SW1: at 1100 mV VVIDEO: at 2775mV : SW1: at 1100 mV SW1: at 1100 mV .. up to that number of "mismatched" regulators. Nobody using DT can/will consume these regulators, so it should not be possible for it to cause any real regulator problems or driver breakages, but it is an easy thing to miss in a kernel log and is an immediate indication of a problem with the device tree authoring. This patch effectively sanity checks the number of counted children of the regulators node vs. the number that actually matched driver names, and sets the appropriate num_regulators value. It also gives a little warning for device tree authors that they MAY have screwed something up, such that this patch does not hide the device tree authoring problem. Signed-off-by: Matt Sealey Tested-by: Steev Klimaszewski Signed-off-by: Mark Brown --- drivers/regulator/mc13xxx-regulator-core.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'drivers/regulator/mc13xxx-regulator-core.c') diff --git a/drivers/regulator/mc13xxx-regulator-core.c b/drivers/regulator/mc13xxx-regulator-core.c index 4ed89c654110..2ecf1d8b6a94 100644 --- a/drivers/regulator/mc13xxx-regulator-core.c +++ b/drivers/regulator/mc13xxx-regulator-core.c @@ -181,12 +181,14 @@ EXPORT_SYMBOL_GPL(mc13xxx_get_num_regulators_dt); struct mc13xxx_regulator_init_data *mc13xxx_parse_regulators_dt( struct platform_device *pdev, struct mc13xxx_regulator *regulators, - int num_regulators) + int num_regulators, int *num_parsed) { struct mc13xxx_regulator_priv *priv = platform_get_drvdata(pdev); struct mc13xxx_regulator_init_data *data, *p; struct device_node *parent, *child; - int i; + int i, parsed = 0; + + *num_parsed = 0; of_node_get(pdev->dev.parent->of_node); parent = of_find_node_by_name(pdev->dev.parent->of_node, "regulators"); @@ -203,16 +205,20 @@ struct mc13xxx_regulator_init_data *mc13xxx_parse_regulators_dt( for (i = 0; i < num_regulators; i++) { if (!of_node_cmp(child->name, regulators[i].desc.name)) { + p->id = i; p->init_data = of_get_regulator_init_data( &pdev->dev, child); p->node = child; p++; + + parsed++; break; } } } + *num_parsed = parsed; return data; } EXPORT_SYMBOL_GPL(mc13xxx_parse_regulators_dt); -- cgit v1.2.3