[PATCH 21/25] fujitsu-laptop: fix error return code

From: Julia Lawall
Date: Sun Dec 29 2013 - 16:52:53 EST


From: Julia Lawall <Julia.Lawall@xxxxxxx>

These functions mix the use of result and error. In acpi_fujitsu_add,
result does not seem useful; it would seem reasonable to propagate the
return value of acpi_bus_update_power in an error case. On the other hand,
in the case of acpi_fujitsu_hotkey_add, there is an initialization of
result that can lead to what looks like a failure case, but that does not
abort the function. The variable result is kept for this case.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
(
if@p1 (\(ret < 0\|ret != 0\))
{ ... return ret; }
|
ret@p1 = 0
)
... when != ret = e1
when != &ret
*if(...)
{
... when != ret = e2
when forall
return ret;
}

// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@xxxxxxx>

---
Not tested. Not sure to be doing the right thing with result in the second
case.

drivers/platform/x86/fujitsu-laptop.c | 15 +++++++--------
1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/drivers/platform/x86/fujitsu-laptop.c b/drivers/platform/x86/fujitsu-laptop.c
index 9d30d69..be02bcc 100644
--- a/drivers/platform/x86/fujitsu-laptop.c
+++ b/drivers/platform/x86/fujitsu-laptop.c
@@ -633,7 +633,6 @@ static struct dmi_system_id fujitsu_dmi_table[] = {

static int acpi_fujitsu_add(struct acpi_device *device)
{
- int result = 0;
int state = 0;
struct input_dev *input;
int error;
@@ -669,8 +668,8 @@ static int acpi_fujitsu_add(struct acpi_device *device)
if (error)
goto err_free_input_dev;

- result = acpi_bus_update_power(fujitsu->acpi_handle, &state);
- if (result) {
+ error = acpi_bus_update_power(fujitsu->acpi_handle, &state);
+ if (error) {
pr_err("Error reading power state\n");
goto err_unregister_input_dev;
}
@@ -700,7 +699,7 @@ static int acpi_fujitsu_add(struct acpi_device *device)
fujitsu->max_brightness = FUJITSU_LCD_N_LEVELS;
get_lcd_level();

- return result;
+ return 0;

err_unregister_input_dev:
input_unregister_device(input);
@@ -708,7 +707,7 @@ err_unregister_input_dev:
err_free_input_dev:
input_free_device(input);
err_stop:
- return result;
+ return error;
}

static int acpi_fujitsu_remove(struct acpi_device *device)
@@ -831,8 +830,8 @@ static int acpi_fujitsu_hotkey_add(struct acpi_device *device)
if (error)
goto err_free_input_dev;

- result = acpi_bus_update_power(fujitsu_hotkey->acpi_handle, &state);
- if (result) {
+ error = acpi_bus_update_power(fujitsu_hotkey->acpi_handle, &state);
+ if (error) {
pr_err("Error reading power state\n");
goto err_unregister_input_dev;
}
@@ -907,7 +906,7 @@ err_free_input_dev:
err_free_fifo:
kfifo_free(&fujitsu_hotkey->fifo);
err_stop:
- return result;
+ return error;
}

static int acpi_fujitsu_hotkey_remove(struct acpi_device *device)

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