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

From: Ziliang Liao
Date: Sun Apr 30 2023 - 08:54:14 EST


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 <saraday@xxxxxxxxxxx>
Reviewed-by: Dongliang Mu <dzm91@xxxxxxxxxxx>
---
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