Messages in this thread |  | | Date | Mon, 24 Feb 2014 14:44:22 +0100 | From | Philippe Rétornaz <> | Subject | Re: [PATCH 13/16] regulator: mc13xxx: Use of_get_child_by_name |
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Hi
This patch breaks DT-Enabled kernel run on non-DT board: [ 0.822977] Unable to handle kernel NULL pointer dereference at virtual address 0000001c (...) [ 0.880320] [<c02f3e94>] (of_get_next_child) from [<c02f5420>] (of_get_child_by_name+0x38/0x50) [ 0.881449] [<c02f5420>] (of_get_child_by_name) from [<c01f6258>] (mc13xxx_get_num_regulators_dt+0x18/0x64) [ 0.882707] [<c01f6258>] (mc13xxx_get_num_regulators_dt) from [<c01f5d38>] (mc13783_regulator_probe+0x34/0x17c) [ 0.884011] [<c01f5d38>] (mc13783_regulator_probe) from [<c021fed0>] (platform_drv_probe+0x20/0x54) [ 0.885182] [<c021fed0>] (platform_drv_probe) from [<c021e674>] (driver_probe_device+0x144/0x360) (...)
Because mc13783-regulator do in its probe: static int mc13783_regulator_probe(struct platform_device *pdev) { (...) int i, num_regulators;
num_regulators = mc13xxx_get_num_regulators_dt(pdev); if (num_regulators <= 0 && pdata) num_regulators = pdata->num_regulators
and mc13xxx_get_num_regulators_dt() do, before your patch:
parent = of_find_node_by_name(pdev->dev.parent->of_node, "regulators"); if (!parent) return -ENODEV;
of_find_node_by_name will return NULL if the node passed is NULL and the DT is non-existant.
But, with your change we use this: parent = of_get_child_by_name(pdev->dev.parent->of_node, "regulators");
Which will OOPS as it does not expect to have a NULL node passed as argument.
So please revert this patch.
Regards,
Philippe
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