From: Dmitry Osipenko <digetx@gmail.com>
To: Thierry Reding <thierry.reding@gmail.com>
Cc: Nicolin Chen <nicoleotsuka@gmail.com>,
joro@8bytes.org, vdumpa@nvidia.com, jonathanh@nvidia.com,
linux-tegra@vger.kernel.org, iommu@lists.linux-foundation.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 2/3] iommu/tegra-smmu: Rework tegra_smmu_probe_device()
Date: Mon, 5 Oct 2020 13:36:55 +0300 [thread overview]
Message-ID: <ae48aaaf-fe10-6de4-06bb-2afbde799168@gmail.com> (raw)
In-Reply-To: <20201005095351.GI425362@ulmo>
05.10.2020 12:53, Thierry Reding пишет:
> On Fri, Oct 02, 2020 at 05:50:08PM +0300, Dmitry Osipenko wrote:
>> 02.10.2020 17:22, Dmitry Osipenko пишет:
>>>> static int tegra_smmu_of_xlate(struct device *dev,
>>>> struct of_phandle_args *args)
>>>> {
>>>> + struct platform_device *iommu_pdev = of_find_device_by_node(args->np);
>>>> + struct tegra_mc *mc = platform_get_drvdata(iommu_pdev);
>>>> u32 id = args->args[0];
>>>>
>>>> + of_node_put(args->np);
>>>> +
>>>> + if (!mc || !mc->smmu)
>>>> + return -EPROBE_DEFER;
>>> platform_get_drvdata(NULL) will crash.
>>>
>>
>> Actually, platform_get_drvdata(NULL) can't happen. I overlooked this.
>
> How so? It's technically possible for the iommus property to reference a
> device tree node for which no platform device will ever be created, in
> which case of_find_device_by_node() will return NULL. That's very
> unlikely and perhaps worth just crashing on to make sure it gets fixed
> immediately.
The tegra_smmu_ops are registered from the SMMU driver itself and MC
driver sets platform data before SMMU is initialized, hence device is
guaranteed to exist and mc can't be NULL.
next prev parent reply other threads:[~2020-10-05 10:37 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-02 6:08 [PATCH v4 0/3] iommu/tegra-smmu: Add PCI support Nicolin Chen
2020-10-02 6:08 ` [PATCH v4 1/3] iommu/tegra-smmu: Use fwspec in tegra_smmu_(de)attach_dev Nicolin Chen
2020-10-02 14:22 ` Dmitry Osipenko
2020-10-02 14:52 ` Dmitry Osipenko
2020-10-02 19:56 ` Nicolin Chen
2020-10-02 14:26 ` Dmitry Osipenko
2020-10-02 14:41 ` Dmitry Osipenko
2020-10-02 19:45 ` Nicolin Chen
2020-10-02 20:12 ` Dmitry Osipenko
2020-10-02 23:53 ` Nicolin Chen
2020-10-03 4:01 ` Dmitry Osipenko
2020-10-02 6:08 ` [PATCH v4 2/3] iommu/tegra-smmu: Rework tegra_smmu_probe_device() Nicolin Chen
2020-10-02 14:22 ` Dmitry Osipenko
2020-10-02 14:58 ` Dmitry Osipenko
2020-10-02 19:53 ` Nicolin Chen
2020-10-05 9:47 ` Thierry Reding
2020-10-02 14:22 ` Dmitry Osipenko
2020-10-02 14:50 ` Dmitry Osipenko
2020-10-05 9:53 ` Thierry Reding
2020-10-05 10:36 ` Dmitry Osipenko [this message]
2020-10-05 11:15 ` Thierry Reding
2020-10-05 13:28 ` Dmitry Osipenko
2020-10-05 14:22 ` Thierry Reding
2020-10-05 9:51 ` Thierry Reding
2020-10-02 14:23 ` Dmitry Osipenko
2020-10-02 18:01 ` Nicolin Chen
2020-10-02 18:20 ` Dmitry Osipenko
2020-10-02 15:02 ` Dmitry Osipenko
2020-10-02 18:58 ` Nicolin Chen
2020-10-05 9:57 ` Thierry Reding
2020-10-06 1:05 ` Nicolin Chen
2020-10-08 9:53 ` Thierry Reding
2020-10-08 21:12 ` Nicolin Chen
2020-10-09 12:25 ` Thierry Reding
2020-10-09 15:54 ` Nicolin Chen
2020-10-02 15:23 ` Dmitry Osipenko
2020-10-02 16:00 ` Dmitry Osipenko
2020-10-02 16:37 ` Dmitry Osipenko
2020-10-02 16:50 ` Dmitry Osipenko
2020-10-02 6:08 ` [PATCH v4 3/3] iommu/tegra-smmu: Add PCI support Nicolin Chen
2020-10-02 14:35 ` Dmitry Osipenko
2020-10-02 17:45 ` Nicolin Chen
2020-10-02 18:04 ` Dmitry Osipenko
2020-10-02 18:04 ` Dmitry Osipenko
2020-10-05 10:04 ` Thierry Reding
2020-10-06 0:54 ` Nicolin Chen
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