[PATCH] platform/x86: panasonic-laptop: simplify allocation of sinf

From: Rosen Penev

Date: Thu Mar 19 2026 - 20:49:56 EST


Change to a flexible array member to allocate once instead of twice.

Allows using __counted_by for extra runtime analysis. Move the counting
variable assignment to right after allocation as required by
__counted_by.

Remove + 1 to allocation. It's already done in the previous line.

Signed-off-by: Rosen Penev <rosenp@xxxxxxxxx>
---
drivers/platform/x86/panasonic-laptop.c | 17 ++++-------------
1 file changed, 4 insertions(+), 13 deletions(-)

diff --git a/drivers/platform/x86/panasonic-laptop.c b/drivers/platform/x86/panasonic-laptop.c
index d923ddaa4849..4d663fffbcc8 100644
--- a/drivers/platform/x86/panasonic-laptop.c
+++ b/drivers/platform/x86/panasonic-laptop.c
@@ -248,11 +248,11 @@ struct pcc_acpi {
int ac_brightness;
int dc_brightness;
int current_brightness;
- u32 *sinf;
struct acpi_device *device;
struct input_dev *input_dev;
struct backlight_device *backlight;
struct platform_device *platform;
+ u32 sinf[] __counted_by(num_sifr);
};

/*
@@ -1017,21 +1017,15 @@ static int acpi_pcc_hotkey_add(struct acpi_device *device)
*/
num_sifr++;

- pcc = kzalloc_obj(struct pcc_acpi);
+ pcc = kzalloc_flex(*pcc, sinf, num_sifr);
if (!pcc) {
pr_err("Couldn't allocate mem for pcc");
return -ENOMEM;
}

- pcc->sinf = kcalloc(num_sifr + 1, sizeof(u32), GFP_KERNEL);
- if (!pcc->sinf) {
- result = -ENOMEM;
- goto out_hotkey;
- }
-
+ pcc->num_sifr = num_sifr;
pcc->device = device;
pcc->handle = device->handle;
- pcc->num_sifr = num_sifr;
device->driver_data = pcc;
strscpy(acpi_device_name(device), ACPI_PCC_DEVICE_NAME);
strscpy(acpi_device_class(device), ACPI_PCC_CLASS);
@@ -1039,7 +1033,7 @@ static int acpi_pcc_hotkey_add(struct acpi_device *device)
result = acpi_pcc_init_input(pcc);
if (result) {
pr_err("Error installing keyinput handler\n");
- goto out_sinf;
+ goto out_hotkey;
}

if (!acpi_pcc_retrieve_biosdata(pcc)) {
@@ -1111,8 +1105,6 @@ static int acpi_pcc_hotkey_add(struct acpi_device *device)
backlight_device_unregister(pcc->backlight);
out_input:
input_unregister_device(pcc->input_dev);
-out_sinf:
- kfree(pcc->sinf);
out_hotkey:
kfree(pcc);

@@ -1140,7 +1132,6 @@ static void acpi_pcc_hotkey_remove(struct acpi_device *device)

input_unregister_device(pcc->input_dev);

- kfree(pcc->sinf);
kfree(pcc);
}

--
2.53.0