[PATCH v3 1/6] ACPI: AC: Remove unnecessary checks

[Michal Wilczynski]

Remove unnecessary checks for NULL for variables that can't be NULL at
the point they're checked for it. Defensive programming is discouraged
in the kernel.

Signed-off-by: Michal Wilczynski <michal.wilczyn...@intel.com>
---
 drivers/acpi/ac.c | 27 ++++-----------------------
 1 file changed, 4 insertions(+), 23 deletions(-)

diff --git a/drivers/acpi/ac.c b/drivers/acpi/ac.c
index aac3e561790c..83d45c681121 100644
--- a/drivers/acpi/ac.c
+++ b/drivers/acpi/ac.c
@@ -131,9 +131,6 @@ static void acpi_ac_notify(acpi_handle handle, u32 event, 
void *data)
        struct acpi_device *device = data;
        struct acpi_ac *ac = acpi_driver_data(device);
 
-       if (!ac)
-               return;
-
        switch (event) {
        default:
                acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",
@@ -216,12 +213,8 @@ static const struct dmi_system_id ac_dmi_table[]  
__initconst = {
 static int acpi_ac_add(struct acpi_device *device)
 {
        struct power_supply_config psy_cfg = {};
-       int result = 0;
-       struct acpi_ac *ac = NULL;
-
-
-       if (!device)
-               return -EINVAL;
+       struct acpi_ac *ac;
+       int result;
 
        ac = kzalloc(sizeof(struct acpi_ac), GFP_KERNEL);
        if (!ac)
@@ -275,16 +268,9 @@ static int acpi_ac_add(struct acpi_device *device)
 #ifdef CONFIG_PM_SLEEP
 static int acpi_ac_resume(struct device *dev)
 {
-       struct acpi_ac *ac;
+       struct acpi_ac *ac = acpi_driver_data(to_acpi_device(dev));
        unsigned int old_state;
 
-       if (!dev)
-               return -EINVAL;
-
-       ac = acpi_driver_data(to_acpi_device(dev));
-       if (!ac)
-               return -EINVAL;
-
        old_state = ac->state;
        if (acpi_ac_get_state(ac))
                return 0;
@@ -299,12 +285,7 @@ static int acpi_ac_resume(struct device *dev)
 
 static void acpi_ac_remove(struct acpi_device *device)
 {
-       struct acpi_ac *ac = NULL;
-
-       if (!device || !acpi_driver_data(device))
-               return;
-
-       ac = acpi_driver_data(device);
+       struct acpi_ac *ac = acpi_driver_data(device);
 
        acpi_dev_remove_notify_handler(device, ACPI_ALL_NOTIFY,
                                       acpi_ac_notify);
-- 
2.41.0