[PATCH] iommu/mediatek-v1: Tidy up probe_finalize

[PATCH] iommu/mediatek-v1: Tidy up probe_finalize

[Robin Murphy]

Krzysztof points out that although the driver now supports COMPILE_TEST
for other architectures, it does not build cleanly with W=1 where the
stubbed-out ARM API can lead to an unused variable warning.

Since this is effectively the correct intent of the code in such cases,
mark it as __maybe_unused, tidying up some cruft in the process.

Reported-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---

Since I'd already got as far as thinking this through, I figure I may
as well save Krzysztof the trouble of rewriting it :)
 
 drivers/iommu/mtk_iommu_v1.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c
index 66824982e05f..2fc18e194e19 100644
--- a/drivers/iommu/mtk_iommu_v1.c
+++ b/drivers/iommu/mtk_iommu_v1.c
@@ -509,14 +509,10 @@ static struct iommu_device *mtk_iommu_v1_probe_device(struct device *dev)
 
 static void mtk_iommu_v1_probe_finalize(struct device *dev)
 {
-	struct dma_iommu_mapping *mtk_mapping;
-	struct mtk_iommu_v1_data *data;
+	__maybe_unused struct mtk_iommu_v1_data *data = dev_iommu_priv_get(dev);
 	int err;
 
-	data        = dev_iommu_priv_get(dev);
-	mtk_mapping = data->mapping;
-
-	err = arm_iommu_attach_device(dev, mtk_mapping);
+	err = arm_iommu_attach_device(dev, data->mapping);
 	if (err)
 		dev_err(dev, "Can't create IOMMU mapping - DMA-OPS will not work\n");
 }
-- 
2.39.2.101.g768bb238c484.dirty

Re: [PATCH] iommu/mediatek-v1: Tidy up probe_finalize

[Yong Wu (吴勇)]

On Fri, 2025-06-27 at 16:07 +0100, Robin Murphy wrote:
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
> 
> 
> Krzysztof points out that although the driver now supports
> COMPILE_TEST
> for other architectures, it does not build cleanly with W=1 where the
> stubbed-out ARM API can lead to an unused variable warning.
> 
> Since this is effectively the correct intent of the code in such
> cases,
> mark it as __maybe_unused, tidying up some cruft in the process.
> 
> Reported-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>

Reviewed-by: Yong Wu <yong.wu@mediatek.com>

> ---
> 
> Since I'd already got as far as thinking this through, I figure I may
> as well save Krzysztof the trouble of rewriting it :)
> 
>  drivers/iommu/mtk_iommu_v1.c | 8 ++------
>  1 file changed, 2 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/iommu/mtk_iommu_v1.c
> b/drivers/iommu/mtk_iommu_v1.c
> index 66824982e05f..2fc18e194e19 100644
> --- a/drivers/iommu/mtk_iommu_v1.c
> +++ b/drivers/iommu/mtk_iommu_v1.c
> @@ -509,14 +509,10 @@ static struct iommu_device
> *mtk_iommu_v1_probe_device(struct device *dev)
> 
>  static void mtk_iommu_v1_probe_finalize(struct device *dev)
>  {
> -       struct dma_iommu_mapping *mtk_mapping;
> -       struct mtk_iommu_v1_data *data;
> +       __maybe_unused struct mtk_iommu_v1_data *data =
> dev_iommu_priv_get(dev);
>         int err;
> 
> -       data        = dev_iommu_priv_get(dev);
> -       mtk_mapping = data->mapping;
> -
> -       err = arm_iommu_attach_device(dev, mtk_mapping);
> +       err = arm_iommu_attach_device(dev, data->mapping);
>         if (err)
>                 dev_err(dev, "Can't create IOMMU mapping - DMA-OPS
> will not work\n");
>  }
> --
> 2.39.2.101.g768bb238c484.dirty
> 

Re: [PATCH] iommu/mediatek-v1: Tidy up probe_finalize

[Krzysztof Kozlowski]

On 27/06/2025 17:07, Robin Murphy wrote:
> Krzysztof points out that although the driver now supports COMPILE_TEST
> for other architectures, it does not build cleanly with W=1 where the
> stubbed-out ARM API can lead to an unused variable warning.
> 
> Since this is effectively the correct intent of the code in such cases,
> mark it as __maybe_unused, tidying up some cruft in the process.
> 
> Reported-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> ---
> 
> Since I'd already got as far as thinking this through, I figure I may
> as well save Krzysztof the trouble of rewriting it :)

Sure, thanks!

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof

Re: [PATCH] iommu/mediatek-v1: Tidy up probe_finalize

[Joerg Roedel]

On Fri, Jun 27, 2025 at 04:07:10PM +0100, Robin Murphy wrote:
>  drivers/iommu/mtk_iommu_v1.c | 8 ++------
>  1 file changed, 2 insertions(+), 6 deletions(-)

Applied, thanks Robin.