* Re: [PATCH] iommu/tegra-smmu: Fix missing put_device() call in tegra_smmu_find
2022-01-07 8:09 [PATCH] iommu/tegra-smmu: Fix missing put_device() call in tegra_smmu_find Miaoqian Lin
@ 2022-01-31 15:25 ` Joerg Roedel
2022-02-16 13:48 ` Thierry Reding
2022-02-28 12:16 ` Joerg Roedel
2 siblings, 0 replies; 4+ messages in thread
From: Joerg Roedel @ 2022-01-31 15:25 UTC (permalink / raw)
To: Miaoqian Lin, Thierry Reding
Cc: Krishna Reddy, Will Deacon, Jonathan Hunter, Nicolin Chen,
linux-tegra, iommu, linux-kernel
Thierry,
does this look correct to you?
Thanks,
Joerg
On Fri, Jan 07, 2022 at 08:09:11AM +0000, Miaoqian Lin wrote:
> The reference taken by 'of_find_device_by_node()' must be released when
> not needed anymore.
> Add the corresponding 'put_device()' in the error handling path.
>
> Fixes: 765a9d1d02b2 ("iommu/tegra-smmu: Fix mc errors on tegra124-nyan")
> Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
> ---
> drivers/iommu/tegra-smmu.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
> index e900e3c46903..2561ce8a2ce8 100644
> --- a/drivers/iommu/tegra-smmu.c
> +++ b/drivers/iommu/tegra-smmu.c
> @@ -808,8 +808,10 @@ static struct tegra_smmu *tegra_smmu_find(struct device_node *np)
> return NULL;
>
> mc = platform_get_drvdata(pdev);
> - if (!mc)
> + if (!mc) {
> + put_device(&pdev->dev);
> return NULL;
> + }
>
> return mc->smmu;
> }
> --
> 2.17.1
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] iommu/tegra-smmu: Fix missing put_device() call in tegra_smmu_find
2022-01-07 8:09 [PATCH] iommu/tegra-smmu: Fix missing put_device() call in tegra_smmu_find Miaoqian Lin
2022-01-31 15:25 ` Joerg Roedel
@ 2022-02-16 13:48 ` Thierry Reding
2022-02-28 12:16 ` Joerg Roedel
2 siblings, 0 replies; 4+ messages in thread
From: Thierry Reding @ 2022-02-16 13:48 UTC (permalink / raw)
To: Miaoqian Lin
Cc: Krishna Reddy, Joerg Roedel, Will Deacon, Jonathan Hunter,
Nicolin Chen, linux-tegra, iommu, linux-kernel
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On Fri, Jan 07, 2022 at 08:09:11AM +0000, Miaoqian Lin wrote:
> The reference taken by 'of_find_device_by_node()' must be released when
> not needed anymore.
> Add the corresponding 'put_device()' in the error handling path.
>
> Fixes: 765a9d1d02b2 ("iommu/tegra-smmu: Fix mc errors on tegra124-nyan")
> Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
> ---
> drivers/iommu/tegra-smmu.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
> index e900e3c46903..2561ce8a2ce8 100644
> --- a/drivers/iommu/tegra-smmu.c
> +++ b/drivers/iommu/tegra-smmu.c
> @@ -808,8 +808,10 @@ static struct tegra_smmu *tegra_smmu_find(struct device_node *np)
> return NULL;
>
> mc = platform_get_drvdata(pdev);
> - if (!mc)
> + if (!mc) {
> + put_device(&pdev->dev);
> return NULL;
> + }
>
> return mc->smmu;
> }
Sorry for the late reply, looks correct. We probably also need a similar
call in ->release_device(). I also wonder if we should be returning an
-EPROBE_DEFER here, which is technically the correct thing to do, though
in practice that will likely never happen because these pointers are set
during an arch_initcall, so should always be available by the time a
driver tries to attach to an IOMMU.
Acked-by: Thierry Reding <treding@nvidia.com>
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^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] iommu/tegra-smmu: Fix missing put_device() call in tegra_smmu_find
2022-01-07 8:09 [PATCH] iommu/tegra-smmu: Fix missing put_device() call in tegra_smmu_find Miaoqian Lin
2022-01-31 15:25 ` Joerg Roedel
2022-02-16 13:48 ` Thierry Reding
@ 2022-02-28 12:16 ` Joerg Roedel
2 siblings, 0 replies; 4+ messages in thread
From: Joerg Roedel @ 2022-02-28 12:16 UTC (permalink / raw)
To: Miaoqian Lin
Cc: Thierry Reding, Krishna Reddy, Will Deacon, Jonathan Hunter,
Nicolin Chen, linux-tegra, iommu, linux-kernel
On Fri, Jan 07, 2022 at 08:09:11AM +0000, Miaoqian Lin wrote:
> The reference taken by 'of_find_device_by_node()' must be released when
> not needed anymore.
> Add the corresponding 'put_device()' in the error handling path.
>
> Fixes: 765a9d1d02b2 ("iommu/tegra-smmu: Fix mc errors on tegra124-nyan")
> Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
> ---
> drivers/iommu/tegra-smmu.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
Applied for v5.17, thanks.
^ permalink raw reply [flat|nested] 4+ messages in thread