2023-04-30 12:55:42

by Ziliang Liao

[permalink] [raw]
Subject: [PATCH 1/2] bus: qcom-ebi2: use prefix devm for clock resource allocation functions

Smatch reports:

drivers/bus/qcom-ebi2.c:387 qcom_ebi2_probe() warn: 'ebi2clk' from
clk_prepare_enable() not released on lines: 358.

drivers/bus/qcom-ebi2.c:387 qcom_ebi2_probe() warn: 'ebi2xclk' from
clk_prepare_enabled() not released on lines: 358.

The clk_disable_unprepare() is only used to explicitly release resources
when the qcom_ebi2_probe() fails, and when executed correctly, it may
cause resource leakage due to unknown release time.

Replace devm_clk_get() and clk_prepare_enable() with
devm_clk_get_enabled() to automatically manage the allocated resources.

Fixes: 335a12754808 ("bus: qcom: add EBI2 driver")
Signed-off-by: Ziliang Liao <[email protected]>
Reviewed-by: Dongliang Mu <[email protected]>
---
The issue is found by static analyzer. The patched code has passed
Smatch checker, but remains untested on real device.

drivers/bus/qcom-ebi2.c | 35 ++++++++---------------------------
1 file changed, 8 insertions(+), 27 deletions(-)

diff --git a/drivers/bus/qcom-ebi2.c b/drivers/bus/qcom-ebi2.c
index c1fef1b4bd89..3999e969e1cf 100644
--- a/drivers/bus/qcom-ebi2.c
+++ b/drivers/bus/qcom-ebi2.c
@@ -303,40 +303,28 @@ static int qcom_ebi2_probe(struct platform_device *pdev)
u32 val;
int ret;

- ebi2xclk = devm_clk_get(dev, "ebi2x");
- if (IS_ERR(ebi2xclk))
+ ebi2xclk = devm_clk_get_enabled(dev, "ebi2x");
+ if (IS_ERR(ebi2xclk)) {
+ dev_err(dev, "could not enable EBI2X clk");
return PTR_ERR(ebi2xclk);
-
- ret = clk_prepare_enable(ebi2xclk);
- if (ret) {
- dev_err(dev, "could not enable EBI2X clk (%d)\n", ret);
- return ret;
}

- ebi2clk = devm_clk_get(dev, "ebi2");
+ ebi2clk = devm_clk_get_enabled(dev, "ebi2");
if (IS_ERR(ebi2clk)) {
- ret = PTR_ERR(ebi2clk);
- goto err_disable_2x_clk;
- }
-
- ret = clk_prepare_enable(ebi2clk);
- if (ret) {
- dev_err(dev, "could not enable EBI2 clk\n");
- goto err_disable_2x_clk;
+ dev_err(dev, "could not enable EBI2 clk");
+ return PTR_ERR(ebi2clk);
}

res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
ebi2_base = devm_ioremap_resource(dev, res);
if (IS_ERR(ebi2_base)) {
- ret = PTR_ERR(ebi2_base);
- goto err_disable_clk;
+ return PTR_ERR(ebi2_base);
}

res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
ebi2_xmem = devm_ioremap_resource(dev, res);
if (IS_ERR(ebi2_xmem)) {
- ret = PTR_ERR(ebi2_xmem);
- goto err_disable_clk;
+ return PTR_ERR(ebi2_xmem);
}

/* Allegedly this turns the power save mode off */
@@ -378,13 +366,6 @@ static int qcom_ebi2_probe(struct platform_device *pdev)
if (have_children)
return of_platform_default_populate(np, NULL, dev);
return 0;
-
-err_disable_clk:
- clk_disable_unprepare(ebi2clk);
-err_disable_2x_clk:
- clk_disable_unprepare(ebi2xclk);
-
- return ret;
}

static const struct of_device_id qcom_ebi2_of_match[] = {
--
2.25.1


2023-04-30 14:07:58

by Ziliang Liao

[permalink] [raw]
Subject: [PATCH 2/2] bus: qcom-ebi2: simplify the code in qcom_ebi2_probe()

The code use platform_get_resource() and devm_ioremap_resource() to
allocate memory resources for the device. It can be simplified by using
devm_platform_ioremap_resource().

Fixes: 335a12754808 ("bus: qcom: add EBI2 driver")
Signed-off-by: Ziliang Liao <[email protected]>
Reviewed-by: Dongliang Mu <[email protected]>
---
drivers/bus/qcom-ebi2.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/bus/qcom-ebi2.c b/drivers/bus/qcom-ebi2.c
index 3999e969e1cf..bd419398d1c1 100644
--- a/drivers/bus/qcom-ebi2.c
+++ b/drivers/bus/qcom-ebi2.c
@@ -294,7 +294,6 @@ static int qcom_ebi2_probe(struct platform_device *pdev)
struct device_node *np = pdev->dev.of_node;
struct device_node *child;
struct device *dev = &pdev->dev;
- struct resource *res;
void __iomem *ebi2_base;
void __iomem *ebi2_xmem;
struct clk *ebi2xclk;
@@ -315,14 +314,12 @@ static int qcom_ebi2_probe(struct platform_device *pdev)
return PTR_ERR(ebi2clk);
}

- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- ebi2_base = devm_ioremap_resource(dev, res);
+ ebi2_base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(ebi2_base)) {
return PTR_ERR(ebi2_base);
}

- res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
- ebi2_xmem = devm_ioremap_resource(dev, res);
+ ebi2_xmem = devm_platform_ioremap_resource(pdev, 1);
if (IS_ERR(ebi2_xmem)) {
return PTR_ERR(ebi2_xmem);
}
--
2.25.1

2023-05-08 13:40:37

by Linus Walleij

[permalink] [raw]
Subject: Re: [PATCH 1/2] bus: qcom-ebi2: use prefix devm for clock resource allocation functions

On Sun, Apr 30, 2023 at 2:53 PM Ziliang Liao <[email protected]> wrote:

> Smatch reports:
>
> drivers/bus/qcom-ebi2.c:387 qcom_ebi2_probe() warn: 'ebi2clk' from
> clk_prepare_enable() not released on lines: 358.
>
> drivers/bus/qcom-ebi2.c:387 qcom_ebi2_probe() warn: 'ebi2xclk' from
> clk_prepare_enabled() not released on lines: 358.
>
> The clk_disable_unprepare() is only used to explicitly release resources
> when the qcom_ebi2_probe() fails, and when executed correctly, it may
> cause resource leakage due to unknown release time.
>
> Replace devm_clk_get() and clk_prepare_enable() with
> devm_clk_get_enabled() to automatically manage the allocated resources.
>
> Fixes: 335a12754808 ("bus: qcom: add EBI2 driver")
> Signed-off-by: Ziliang Liao <[email protected]>
> Reviewed-by: Dongliang Mu <[email protected]>

Looks good:
Reviewed-by: Linus Walleij <[email protected]>

I think Bjorn can queue this in the Qualcomm ARM tree.

Yours,
Linus Walleij

2023-05-08 13:58:55

by Linus Walleij

[permalink] [raw]
Subject: Re: [PATCH 2/2] bus: qcom-ebi2: simplify the code in qcom_ebi2_probe()

On Sun, Apr 30, 2023 at 2:54 PM Ziliang Liao <[email protected]> wrote:

> The code use platform_get_resource() and devm_ioremap_resource() to
> allocate memory resources for the device. It can be simplified by using
> devm_platform_ioremap_resource().
>
> Fixes: 335a12754808 ("bus: qcom: add EBI2 driver")

It doesn't need Fixes: if it's not a bug, but who cares. Maybe
the stable maintainers care.

> Signed-off-by: Ziliang Liao <[email protected]>
> Reviewed-by: Dongliang Mu <[email protected]>

Reviewed-by: Linus Walleij <[email protected]>

Yours,
Linus Walleij

2023-05-08 16:38:28

by Ziliang Liao

[permalink] [raw]
Subject: Re: [PATCH 2/2] bus: qcom-ebi2: simplify the code in qcom_ebi2_probe()

Thanks for your advice.
Do I need to delete the Fixes in [PATCH 2/2] and resend another patch set?

> On Sun, Apr 30, 2023 at 2:54 PM Ziliang Liao <[email protected]> wrote:
>
>> The code use platform_get_resource() and devm_ioremap_resource() to
>> allocate memory resources for the device. It can be simplified by using
>> devm_platform_ioremap_resource().
>>
>> Fixes: 335a12754808 ("bus: qcom: add EBI2 driver")
> It doesn't need Fixes: if it's not a bug, but who cares. Maybe
> the stable maintainers care.
>
>> Signed-off-by: Ziliang Liao <[email protected]>
>> Reviewed-by: Dongliang Mu <[email protected]>
> Reviewed-by: Linus Walleij <[email protected]>
>
> Yours,
> Linus Walleij

2023-05-09 07:35:55

by Linus Walleij

[permalink] [raw]
Subject: Re: [PATCH 2/2] bus: qcom-ebi2: simplify the code in qcom_ebi2_probe()

On Mon, May 8, 2023 at 6:22 PM Ziliang Liao <[email protected]> wrote:

> Thanks for your advice.
> Do I need to delete the Fixes in [PATCH 2/2] and resend another patch set?

No I think Bjorn can delete it while applying the patch.

Yours,
Linus Walleij