[PATCH 1/2] HID: trivial devm conversion for special hid drivers

From: Benjamin Tissoires
Date: Wed Jul 24 2013 - 11:32:22 EST


It is safe to use devres allocation within the hid subsystem:
- the devres release is called _after_ the call to .remove(), meaning
that no freed pointers will exists while removing the device
- if a .probe() fails, devres releases all the allocated ressources
before going to the next driver: there will not be ghost ressources
attached to a hid device if several drivers are probed.

Given that, we can clean up a little some of the HID drivers. These ones
are trivial:
- there is only one kzalloc in the driver
- the .remove() callback contains only one kfree on top of hid_hw_stop()
- the error path in the probe is easy enough to be manually checked

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
---
drivers/hid/hid-a4tech.c | 23 ++++-------------------
drivers/hid/hid-apple.c | 16 +++-------------
drivers/hid/hid-magicmouse.c | 17 +++--------------
drivers/hid/hid-sony.c | 9 +++------
drivers/hid/hid-zydacron.c | 19 +++----------------
5 files changed, 16 insertions(+), 68 deletions(-)

diff --git a/drivers/hid/hid-a4tech.c b/drivers/hid/hid-a4tech.c
index 7c5507e..8d4e999 100644
--- a/drivers/hid/hid-a4tech.c
+++ b/drivers/hid/hid-a4tech.c
@@ -90,11 +90,10 @@ static int a4_probe(struct hid_device *hdev, const struct hid_device_id *id)
struct a4tech_sc *a4;
int ret;

- a4 = kzalloc(sizeof(*a4), GFP_KERNEL);
+ a4 = devm_kzalloc(&hdev->dev, sizeof(*a4), GFP_KERNEL);
if (a4 == NULL) {
hid_err(hdev, "can't alloc device descriptor\n");
- ret = -ENOMEM;
- goto err_free;
+ return -ENOMEM;
}

a4->quirks = id->driver_data;
@@ -104,29 +103,16 @@ static int a4_probe(struct hid_device *hdev, const struct hid_device_id *id)
ret = hid_parse(hdev);
if (ret) {
hid_err(hdev, "parse failed\n");
- goto err_free;
+ return ret;
}

ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
- if (ret) {
+ if (ret)
hid_err(hdev, "hw start failed\n");
- goto err_free;
- }

- return 0;
-err_free:
- kfree(a4);
return ret;
}

-static void a4_remove(struct hid_device *hdev)
-{
- struct a4tech_sc *a4 = hid_get_drvdata(hdev);
-
- hid_hw_stop(hdev);
- kfree(a4);
-}
-
static const struct hid_device_id a4_devices[] = {
{ HID_USB_DEVICE(USB_VENDOR_ID_A4TECH, USB_DEVICE_ID_A4TECH_WCP32PU),
.driver_data = A4_2WHEEL_MOUSE_HACK_7 },
@@ -144,7 +130,6 @@ static struct hid_driver a4_driver = {
.input_mapped = a4_input_mapped,
.event = a4_event,
.probe = a4_probe,
- .remove = a4_remove,
};
module_hid_driver(a4_driver);

diff --git a/drivers/hid/hid-apple.c b/drivers/hid/hid-apple.c
index c7710b5..881cf7b 100644
--- a/drivers/hid/hid-apple.c
+++ b/drivers/hid/hid-apple.c
@@ -349,7 +349,7 @@ static int apple_probe(struct hid_device *hdev,
unsigned int connect_mask = HID_CONNECT_DEFAULT;
int ret;

- asc = kzalloc(sizeof(*asc), GFP_KERNEL);
+ asc = devm_kzalloc(&hdev->dev, sizeof(*asc), GFP_KERNEL);
if (asc == NULL) {
hid_err(hdev, "can't alloc apple descriptor\n");
return -ENOMEM;
@@ -362,7 +362,7 @@ static int apple_probe(struct hid_device *hdev,
ret = hid_parse(hdev);
if (ret) {
hid_err(hdev, "parse failed\n");
- goto err_free;
+ return ret;
}

if (quirks & APPLE_HIDDEV)
@@ -373,19 +373,10 @@ static int apple_probe(struct hid_device *hdev,
ret = hid_hw_start(hdev, connect_mask);
if (ret) {
hid_err(hdev, "hw start failed\n");
- goto err_free;
+ return ret;
}

return 0;
-err_free:
- kfree(asc);
- return ret;
-}
-
-static void apple_remove(struct hid_device *hdev)
-{
- hid_hw_stop(hdev);
- kfree(hid_get_drvdata(hdev));
}

static const struct hid_device_id apple_devices[] = {
@@ -551,7 +542,6 @@ static struct hid_driver apple_driver = {
.id_table = apple_devices,
.report_fixup = apple_report_fixup,
.probe = apple_probe,
- .remove = apple_remove,
.event = apple_event,
.input_mapping = apple_input_mapping,
.input_mapped = apple_input_mapped,
diff --git a/drivers/hid/hid-magicmouse.c b/drivers/hid/hid-magicmouse.c
index 5bc3734..d393eb7 100644
--- a/drivers/hid/hid-magicmouse.c
+++ b/drivers/hid/hid-magicmouse.c
@@ -484,7 +484,7 @@ static int magicmouse_probe(struct hid_device *hdev,
struct hid_report *report;
int ret;

- msc = kzalloc(sizeof(*msc), GFP_KERNEL);
+ msc = devm_kzalloc(&hdev->dev, sizeof(*msc), GFP_KERNEL);
if (msc == NULL) {
hid_err(hdev, "can't alloc magicmouse descriptor\n");
return -ENOMEM;
@@ -498,13 +498,13 @@ static int magicmouse_probe(struct hid_device *hdev,
ret = hid_parse(hdev);
if (ret) {
hid_err(hdev, "magicmouse hid parse failed\n");
- goto err_free;
+ return ret;
}

ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
if (ret) {
hid_err(hdev, "magicmouse hw start failed\n");
- goto err_free;
+ return ret;
}

if (!msc->input) {
@@ -548,19 +548,9 @@ static int magicmouse_probe(struct hid_device *hdev,
return 0;
err_stop_hw:
hid_hw_stop(hdev);
-err_free:
- kfree(msc);
return ret;
}

-static void magicmouse_remove(struct hid_device *hdev)
-{
- struct magicmouse_sc *msc = hid_get_drvdata(hdev);
-
- hid_hw_stop(hdev);
- kfree(msc);
-}
-
static const struct hid_device_id magic_mice[] = {
{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_APPLE,
USB_DEVICE_ID_APPLE_MAGICMOUSE), .driver_data = 0 },
@@ -574,7 +564,6 @@ static struct hid_driver magicmouse_driver = {
.name = "magicmouse",
.id_table = magic_mice,
.probe = magicmouse_probe,
- .remove = magicmouse_remove,
.raw_event = magicmouse_raw_event,
.input_mapping = magicmouse_input_mapping,
.input_configured = magicmouse_input_configured,
diff --git a/drivers/hid/hid-sony.c b/drivers/hid/hid-sony.c
index 87fbe29..30dbb6b 100644
--- a/drivers/hid/hid-sony.c
+++ b/drivers/hid/hid-sony.c
@@ -624,7 +624,7 @@ static int sony_probe(struct hid_device *hdev, const struct hid_device_id *id)
struct sony_sc *sc;
unsigned int connect_mask = HID_CONNECT_DEFAULT;

- sc = kzalloc(sizeof(*sc), GFP_KERNEL);
+ sc = devm_kzalloc(&hdev->dev, sizeof(*sc), GFP_KERNEL);
if (sc == NULL) {
hid_err(hdev, "can't alloc sony descriptor\n");
return -ENOMEM;
@@ -636,7 +636,7 @@ static int sony_probe(struct hid_device *hdev, const struct hid_device_id *id)
ret = hid_parse(hdev);
if (ret) {
hid_err(hdev, "parse failed\n");
- goto err_free;
+ return ret;
}

if (sc->quirks & VAIO_RDESC_CONSTANT)
@@ -649,7 +649,7 @@ static int sony_probe(struct hid_device *hdev, const struct hid_device_id *id)
ret = hid_hw_start(hdev, connect_mask);
if (ret) {
hid_err(hdev, "hw start failed\n");
- goto err_free;
+ return ret;
}

if (sc->quirks & SIXAXIS_CONTROLLER_USB) {
@@ -669,8 +669,6 @@ static int sony_probe(struct hid_device *hdev, const struct hid_device_id *id)
return 0;
err_stop:
hid_hw_stop(hdev);
-err_free:
- kfree(sc);
return ret;
}

@@ -682,7 +680,6 @@ static void sony_remove(struct hid_device *hdev)
buzz_remove(hdev);

hid_hw_stop(hdev);
- kfree(sc);
}

static const struct hid_device_id sony_devices[] = {
diff --git a/drivers/hid/hid-zydacron.c b/drivers/hid/hid-zydacron.c
index e4cddec..1a660bd 100644
--- a/drivers/hid/hid-zydacron.c
+++ b/drivers/hid/hid-zydacron.c
@@ -169,7 +169,7 @@ static int zc_probe(struct hid_device *hdev, const struct hid_device_id *id)
int ret;
struct zc_device *zc;

- zc = kzalloc(sizeof(*zc), GFP_KERNEL);
+ zc = devm_kzalloc(&hdev->dev, sizeof(*zc), GFP_KERNEL);
if (zc == NULL) {
hid_err(hdev, "can't alloc descriptor\n");
return -ENOMEM;
@@ -180,28 +180,16 @@ static int zc_probe(struct hid_device *hdev, const struct hid_device_id *id)
ret = hid_parse(hdev);
if (ret) {
hid_err(hdev, "parse failed\n");
- goto err_free;
+ return ret;
}

ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
if (ret) {
hid_err(hdev, "hw start failed\n");
- goto err_free;
+ return ret;
}

return 0;
-err_free:
- kfree(zc);
-
- return ret;
-}
-
-static void zc_remove(struct hid_device *hdev)
-{
- struct zc_device *zc = hid_get_drvdata(hdev);
-
- hid_hw_stop(hdev);
- kfree(zc);
}

static const struct hid_device_id zc_devices[] = {
@@ -217,7 +205,6 @@ static struct hid_driver zc_driver = {
.input_mapping = zc_input_mapping,
.raw_event = zc_raw_event,
.probe = zc_probe,
- .remove = zc_remove,
};
module_hid_driver(zc_driver);

--
1.8.3.1

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