[PATCH] usb: musb/backfin: Introduce the use of the managed version of kzalloc

From: Himangi Saraogi
Date: Sun Jun 01 2014 - 16:43:32 EST


This patch moves data allocated using kzalloc to managed data allocated
using devm_kzalloc and cleans now unnecessary kfrees in probe and remove
functions. Also, a label is done away with and err2 and err3 renamed.

The following Coccinelle semantic patch was used for making the change:

@platform@
identifier p, probefn, removefn;
@@
struct platform_driver p = {
.probe = probefn,
.remove = removefn,
};

@prb@
identifier platform.probefn, pdev;
expression e, e1, e2;
@@
probefn(struct platform_device *pdev, ...) {
<+...
- e = kzalloc(e1, e2)
+ e = devm_kzalloc(&pdev->dev, e1, e2)
...
?-kfree(e);
...+>
}

@rem depends on prb@
identifier platform.removefn;
expression e;
@@
removefn(...) {
<...
- kfree(e);
...>
}

Signed-off-by: Himangi Saraogi <himangi774@xxxxxxxxx>
Acked-by: Julia Lawall <julia.lawall@xxxxxxx>
---
Not compile tested due to incompatible architechture.

why is platform_device_alloc called for allocating musb from within the
platform driver probe function where presumably the platform device structure
is already available? I would like to know whether the incoming pdev structure
is somehow not usable or it is a parent device of the device to be used.

drivers/usb/musb/blackfin.c | 20 ++++++++------------
1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/drivers/usb/musb/blackfin.c b/drivers/usb/musb/blackfin.c
index d40d5f0..ac4422b 100644
--- a/drivers/usb/musb/blackfin.c
+++ b/drivers/usb/musb/blackfin.c
@@ -455,7 +455,7 @@ static int bfin_probe(struct platform_device *pdev)

int ret = -ENOMEM;

- glue = kzalloc(sizeof(*glue), GFP_KERNEL);
+ glue = devm_kzalloc(&pdev->dev, sizeof(*glue), GFP_KERNEL);
if (!glue) {
dev_err(&pdev->dev, "failed to allocate glue context\n");
goto err0;
@@ -464,7 +464,7 @@ static int bfin_probe(struct platform_device *pdev)
musb = platform_device_alloc("musb-hdrc", PLATFORM_DEVID_AUTO);
if (!musb) {
dev_err(&pdev->dev, "failed to allocate musb device\n");
- goto err1;
+ goto err0;
}

musb->dev.parent = &pdev->dev;
@@ -478,7 +478,7 @@ static int bfin_probe(struct platform_device *pdev)

glue->phy = usb_phy_generic_register();
if (IS_ERR(glue->phy))
- goto err2;
+ goto err1;
platform_set_drvdata(pdev, glue);

memset(musb_resources, 0x00, sizeof(*musb_resources) *
@@ -498,31 +498,28 @@ static int bfin_probe(struct platform_device *pdev)
ARRAY_SIZE(musb_resources));
if (ret) {
dev_err(&pdev->dev, "failed to add resources\n");
- goto err3;
+ goto err2;
}

ret = platform_device_add_data(musb, pdata, sizeof(*pdata));
if (ret) {
dev_err(&pdev->dev, "failed to add platform_data\n");
- goto err3;
+ goto err2;
}

ret = platform_device_add(musb);
if (ret) {
dev_err(&pdev->dev, "failed to register musb device\n");
- goto err3;
+ goto err2;
}

return 0;

-err3:
- usb_phy_generic_unregister(glue->phy);
-
err2:
- platform_device_put(musb);
+ usb_phy_generic_unregister(glue->phy);

err1:
- kfree(glue);
+ platform_device_put(musb);

err0:
return ret;
@@ -534,7 +531,6 @@ static int bfin_remove(struct platform_device *pdev)

platform_device_unregister(glue->musb);
usb_phy_generic_unregister(glue->phy);
- kfree(glue);

return 0;
}
--
1.9.1

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