Messages in this thread |  | | Date | Mon, 24 Feb 2014 16:07:15 +0100 | From | Philippe Rétornaz <> | Subject | Re: [PATCH 13/16] regulator: mc13xxx: Use of_get_child_by_name |
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Le 24/02/2014 15:51, Sachin Kamat a écrit : > On 24 February 2014 19:14, Philippe Rétornaz > <philippe.retornaz@epfl.ch> wrote: >> 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. > > Sorry for the issue caused due to this patch. I would prefer to try > to have this fixed before reverting. Can you please try with below > change and let me know if it works: > > parent = of_get_child_by_name(pdev->dev->of_node, "regulators"); >
You meant pdev->dev.of_node here I guess ? This still OOPS as the board is not booting with DT, so all of_node are NULL.
> Also, how about adding NULL check to see it the node exists at all? >
Could be an option. BTW, mc13xxx_parse_regulators_dt() has the same problem.
Regards,
Philippe
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