[PATCH 2/2] usb: bdc: Fix a resource leak in the error handling path of 'bdc_probe()'

From: Christophe JAILLET
Date: Wed Aug 18 2021 - 15:32:55 EST


If an error occurs after a successful 'clk_prepare_enable()' call, it must
be undone by a corresponding 'clk_disable_unprepare()' call.
This call is already present in the remove function.

Add this call in the error handling path and reorder the code so that the
'clk_prepare_enable()' call happens later in the function.
The goal is to have as much managed resources functions as possible
before the 'clk_prepare_enable()' call in order to keep the error handling
path simple.

While at it, remove the now unneeded 'clk' variable.

Fixes: c87dca047849 ("usb: bdc: Add clock enable for new chips with a separate BDC clock")
Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
Review with care.
I don't like shuffling code like that because of possible side effect.
Moving the code related to this clk looks fine to me, but who knows...
---
drivers/usb/gadget/udc/bdc/bdc_core.c | 27 +++++++++++++--------------
1 file changed, 13 insertions(+), 14 deletions(-)

diff --git a/drivers/usb/gadget/udc/bdc/bdc_core.c b/drivers/usb/gadget/udc/bdc/bdc_core.c
index 251db57e51fa..fa1a3908ec3b 100644
--- a/drivers/usb/gadget/udc/bdc/bdc_core.c
+++ b/drivers/usb/gadget/udc/bdc/bdc_core.c
@@ -488,27 +488,14 @@ static int bdc_probe(struct platform_device *pdev)
int irq;
u32 temp;
struct device *dev = &pdev->dev;
- struct clk *clk;
int phy_num;

dev_dbg(dev, "%s()\n", __func__);

- clk = devm_clk_get_optional(dev, "sw_usbd");
- if (IS_ERR(clk))
- return PTR_ERR(clk);
-
- ret = clk_prepare_enable(clk);
- if (ret) {
- dev_err(dev, "could not enable clock\n");
- return ret;
- }
-
bdc = devm_kzalloc(dev, sizeof(*bdc), GFP_KERNEL);
if (!bdc)
return -ENOMEM;

- bdc->clk = clk;
-
bdc->regs = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(bdc->regs))
return PTR_ERR(bdc->regs);
@@ -545,10 +532,20 @@ static int bdc_probe(struct platform_device *pdev)
}
}

+ bdc->clk = devm_clk_get_optional(dev, "sw_usbd");
+ if (IS_ERR(bdc->clk))
+ return PTR_ERR(bdc->clk);
+
+ ret = clk_prepare_enable(bdc->clk);
+ if (ret) {
+ dev_err(dev, "could not enable clock\n");
+ return ret;
+ }
+
ret = bdc_phy_init(bdc);
if (ret) {
dev_err(bdc->dev, "BDC phy init failure:%d\n", ret);
- return ret;
+ goto disable_clk;
}

temp = bdc_readl(bdc->regs, BDC_BDCCAP1);
@@ -581,6 +578,8 @@ static int bdc_probe(struct platform_device *pdev)
bdc_hw_exit(bdc);
phycleanup:
bdc_phy_exit(bdc);
+disable_clk:
+ clk_disable_unprepare(bdc->clk);
return ret;
}

--
2.30.2