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Groups > linux.kernel > #1626310
| From | Leo Yan <leo.yan@linaro.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v6 6/8] coresight: add support for CPU debug module |
| Date | 2017-04-19 17:10 +0200 |
| Message-ID | <txZp3-4Zt-87@gated-at.bofh.it> (permalink) |
| References | <ttfNL-DZ-7@gated-at.bofh.it> <ttfNM-DZ-25@gated-at.bofh.it> <txXQd-3X1-1@gated-at.bofh.it> <txYVY-4yJ-19@gated-at.bofh.it> <txYVX-4yJ-17@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Wed, Apr 19, 2017 at 03:32:39PM +0100, Suzuki K Poulose wrote:
[...]
> >>>+static int debug_probe(struct amba_device *adev, const struct amba_id *id)
> >>>+{
> >>>+ void __iomem *base;
> >>>+ struct device *dev = &adev->dev;
> >>>+ struct debug_drvdata *drvdata;
> >>>+ struct resource *res = &adev->res;
> >>>+ struct device_node *np = adev->dev.of_node;
> >>>+ int ret;
> >>>+
> >>>+ drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
> >>>+ if (!drvdata)
> >>>+ return -ENOMEM;
> >>>+
> >>>+ drvdata->cpu = np ? of_coresight_get_cpu(np) : 0;
> >>>+ if (per_cpu(debug_drvdata, drvdata->cpu)) {
> >>>+ dev_err(dev, "CPU%d drvdata has been initialized\n",
> >>>+ drvdata->cpu);
> >>
> >>May be we could warn about a possible issue in the DT ?
> >
> >So can I understand the suggestion is to add warning in function
> >of_coresight_get_cpu() when cannot find CPU number, and here directly
> >bail out?
>
> No. One could have single CPU DT, where he doesn't need to provide the CPU number.
> Hence, it doesn't make sense to WARN in of_coresight_get_cpu().
>
> But when we hit the case above, we find that the some node was registered for
> the given CPU (be it 0 or any other), which is definitely an error in DT. Due to
>
> 1) Hasn't specified the CPU number for more than one node
>
> OR
>
> 2) CPU number duplicated in the more than one nodes.
Thanks for explaination. It's clear for me now.
> Cheers
> Suzuki
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Re: [PATCH v6 6/8] coresight: add support for CPU debug module Suzuki K Poulose <Suzuki.Poulose@arm.com> - 2017-04-19 15:30 +0200
Re: [PATCH v6 6/8] coresight: add support for CPU debug module Suzuki K Poulose <Suzuki.Poulose@arm.com> - 2017-04-19 16:40 +0200
Re: [PATCH v6 6/8] coresight: add support for CPU debug module Leo Yan <leo.yan@linaro.org> - 2017-04-19 17:10 +0200
Re: [PATCH v6 6/8] coresight: add support for CPU debug module Leo Yan <leo.yan@linaro.org> - 2017-04-19 16:40 +0200
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