Re: [PATCH] platform/x86: dell-privacy: Add support for new privacy driver
From: Barnabás Pőcze
Date: Tue Nov 03 2020 - 14:14:49 EST
Hi
(I really hope Hans and Mark won't get mad at me for writing some thoughts about
this patch.)
First of all, indentation should be tabs (= 8 spaces), not spaces. If I see it
correctly, the two are mixed here.
And please make the printed messages consistent (capitalization, etc.),
I believe punctuation at the end is not necessary, and don't leave whitespaces
between the text and newline character. Please always run `checkpatch` on the patch
to see what can/needs to be improved.
There are also parts in the code (variables not actually used, etc.) that make me
feel like it's somewhat unfinished, or rather, incomplete.
Both `dell-privacy-acpi` and `dell-privacy-wmi` have the same comment:
"Dell privacy notification driver", but surely they are not the same thing?
I have also added a couple comments inline.
> From: perry_yuan <perry_yuan@xxxxxxxx>
>
> add support for dell privacy driver for the dell units equipped
> hardware privacy design, which protect users privacy
> of audio and camera from hardware level. once the audio or camera
> privacy mode enabled, any applications will not get any audio or
> video stream.
> when user pressed ctrl+F4 hotkey, audio privacy mode will be enabled
> and camera mute hotkey is ctrl+F9.
>
> Signed-off-by: Perry Yuan <perry_yuan@xxxxxxxx>
> Signed-off-by: Limonciello Mario <mario_limonciello@xxxxxxxx>
> ---
> drivers/platform/x86/Kconfig | 12 ++
> drivers/platform/x86/Makefile | 4 +-
> drivers/platform/x86/dell-laptop.c | 41 ++--
> drivers/platform/x86/dell-privacy-acpi.c | 139 ++++++++++++
> drivers/platform/x86/dell-privacy-wmi.c | 259 +++++++++++++++++++++++
> drivers/platform/x86/dell-privacy-wmi.h | 23 ++
> drivers/platform/x86/dell-wmi.c | 90 ++++----
> 7 files changed, 513 insertions(+), 55 deletions(-)
> create mode 100644 drivers/platform/x86/dell-privacy-acpi.c
> create mode 100644 drivers/platform/x86/dell-privacy-wmi.c
> create mode 100644 drivers/platform/x86/dell-privacy-wmi.h
>
> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> index 40219bba6801..0cb6bf5a9565 100644
> --- a/drivers/platform/x86/Kconfig
> +++ b/drivers/platform/x86/Kconfig
> @@ -454,6 +454,18 @@ config DELL_WMI_LED
> This adds support for the Latitude 2100 and similar
> notebooks that have an external LED.
>
> +config DELL_PRIVACY
> + tristate "Dell Hardware Privacy Support"
> + depends on ACPI
> + depends on ACPI_WMI
> + depends on INPUT
> + depends on DELL_LAPTOP
> + select DELL_WMI
> + help
> + This driver provides a driver to support messaging related to the
I'm not a native English speaker, but "messaging" seems a strange choice of
words to me here.
> + privacy button presses on applicable Dell laptops from 2021 and
> + newer.
I have the same feeling about "from 2021 and newer".
> +
> config AMILO_RFKILL
> tristate "Fujitsu-Siemens Amilo rfkill support"
> depends on RFKILL
> diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
> index 5f823f7eff45..111f7215db2f 100644
> --- a/drivers/platform/x86/Makefile
> +++ b/drivers/platform/x86/Makefile
> @@ -47,7 +47,9 @@ obj-$(CONFIG_DELL_WMI) += dell-wmi.o
> obj-$(CONFIG_DELL_WMI_DESCRIPTOR) += dell-wmi-descriptor.o
> obj-$(CONFIG_DELL_WMI_AIO) += dell-wmi-aio.o
> obj-$(CONFIG_DELL_WMI_LED) += dell-wmi-led.o
> -
> +obj-$(CONFIG_DELL_PRIVACY) += dell-privacy.o
> +dell-privacy-objs := dell-privacy-wmi.o \
> + dell-privacy-acpi.o
> # Fujitsu
> obj-$(CONFIG_AMILO_RFKILL) += amilo-rfkill.o
> obj-$(CONFIG_FUJITSU_LAPTOP) += fujitsu-laptop.o
> diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c
> index 5e9c2296931c..12b91de09356 100644
> -- a/drivers/platform/x86/dell-laptop.c
> ++ b/drivers/platform/x86/dell-laptop.c
> @@ -30,6 +30,7 @@
> #include <acpi/video.h>
> #include "dell-rbtn.h"
> #include "dell-smbios.h"
> #include "dell-privacy-wmi.h"
>
> struct quirk_entry {
> bool touchpad_led;
> @@ -90,6 +91,7 @@ static struct rfkill *wifi_rfkill;
> static struct rfkill *bluetooth_rfkill;
> static struct rfkill *wwan_rfkill;
> static bool force_rfkill;
> static bool privacy_valid;
>
> module_param(force_rfkill, bool, 0444);
> MODULE_PARM_DESC(force_rfkill, "enable rfkill on non whitelisted models");
> @@ -2202,20 +2204,25 @@ static int __init dell_init(void)
> debugfs_create_file("rfkill", 0444, dell_laptop_dir, NULL,
> &dell_debugfs_fops);
>
> dell_laptop_register_notifier(&dell_laptop_notifier);
>
> if (dell_smbios_find_token(GLOBAL_MIC_MUTE_DISABLE) &&
> dell_smbios_find_token(GLOBAL_MIC_MUTE_ENABLE)) {
> micmute_led_cdev.brightness = ledtrig_audio_get(LED_AUDIO_MICMUTE);
> ret = led_classdev_register(&platform_device->dev, &micmute_led_cdev);
> if (ret < 0)
> goto fail_led;
> }
>
> if (acpi_video_get_backlight_type() != acpi_backlight_vendor)
> return 0;
>
> token = dell_smbios_find_token(BRIGHTNESS_TOKEN);
> dell_laptop_register_notifier(&dell_laptop_notifier);
>
> if (dell_smbios_find_token(GLOBAL_MIC_MUTE_DISABLE) &&
> dell_smbios_find_token(GLOBAL_MIC_MUTE_ENABLE)) {
> #if IS_ENABLED(CONFIG_DELL_PRIVACY)
> privacy_valid = dell_privacy_valid() == -ENODEV;
`dell_privacy_valid()` returns `bool`.
> #endif
> if (!privacy_valid) {
> micmute_led_cdev.brightness = ledtrig_audio_get(LED_AUDIO_MICMUTE);
> ret = led_classdev_register(&platform_device->dev, &micmute_led_cdev);
> if (ret < 0)
> goto fail_led;
> }
> }
>
> if (acpi_video_get_backlight_type() != acpi_backlight_vendor)
> return 0;
>
> token = dell_smbios_find_token(BRIGHTNESS_TOKEN);
> if (token) {
> struct calling_interface_buffer buffer;
>
> @@ -2257,7 +2264,8 @@ static int __init dell_init(void)
> fail_get_brightness:
> backlight_device_unregister(dell_backlight_device);
> fail_backlight:
> led_classdev_unregister(&micmute_led_cdev);
> if (!privacy_valid)
> led_classdev_unregister(&micmute_led_cdev);
> fail_led:
> dell_cleanup_rfkill();
> fail_rfkill:
> @@ -2278,7 +2286,8 @@ static void __exit dell_exit(void)
> touchpad_led_exit();
> kbd_led_exit();
> backlight_device_unregister(dell_backlight_device);
> led_classdev_unregister(&micmute_led_cdev);
> if (!privacy_valid)
> led_classdev_unregister(&micmute_led_cdev);
> dell_cleanup_rfkill();
> if (platform_device) {
> platform_device_unregister(platform_device);
> diff --git a/drivers/platform/x86/dell-privacy-acpi.c b/drivers/platform/x86/dell-privacy-acpi.c
> new file mode 100644
> index 000000000000..516cd99167c3
> --- /dev/null
> +++ b/drivers/platform/x86/dell-privacy-acpi.c
> @@ -0,0 +1,139 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Dell privacy notification driver
> + *
> + * Copyright (C) 2021 Dell Inc. All Rights Reserved.
> + */
> +
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
> +#include <linux/acpi.h>
> +#include <linux/device.h>
> +#include <linux/fs.h>
> +#include <linux/kernel.h>
> +#include <linux/leds.h>
> +#include <linux/module.h>
> +#include <linux/string.h>
> +#include <linux/sysfs.h>
> +#include <linux/types.h>
> +#include <linux/wmi.h>
> +#include <linux/slab.h>
> +#include <linux/platform_device.h>
> +#include "dell-privacy-wmi.h"
> +
> +#define PRIVACY_PlATFORM_NAME "dell-privacy-acpi"
^
should be upper case
> +#define ACPI_PRIVACY_DEVICE "\\_SB.PC00.LPCB.ECDV"
> +#define ACPI_PRIVACY_EC_ACK ACPI_PRIVACY_DEVICE ".ECAK"
> +
> +static struct platform_device *privacy_acpi_pdev;
> +
> +struct privacy_acpi_priv {
> + struct device *dev;
> + struct acpi_device *acpi_dev;
> + struct input_dev *input_dev;
> + struct platform_device *platform_device;
> +};
> +
> +static int micmute_led_set(struct led_classdev *led_cdev,
> + enum led_brightness brightness)
> +{
> + acpi_status status;
> +
> + status = acpi_evaluate_object(NULL, ACPI_PRIVACY_EC_ACK, NULL, NULL);
The handle of "ACPI_PRIVACY_DEVICE" is queried in `privacy_acpi_probe()`. Why
is that not used here?
> + if (ACPI_FAILURE(status)) {
> + dev_err(led_cdev->dev, "Error setting privacy audio EC ack value: %d\n",status);
^
missing space -/
I think `acpi_format_exception()` could be used here.
I don't quite see why brightness is completely ignored? Does this just toggle
the LED state? Even in that case I think something should be done to avoid the
sysfs attribute showing brightness=1 while the LED is actually off.
Does the `ACPI_PRIVACY_EC_ACK` method (?) acknowledge something? If so, what? And
why is it called in the brightness setting method of a LED class device?
> + return -EIO;
> + }
> + return 0;
> +}
> +
> +static struct led_classdev micmute_led_cdev = {
> + .name = "platform::micmute",
> + .max_brightness = 1,
> + .brightness_set_blocking = micmute_led_set,
> + .default_trigger = "audio-micmute",
> +};
There is also the exact same `micmute_led_cdev` is in dell-laptop.c. Both are
valid? What's the difference? Why can't the LED be handled in just a single place?
> [...]
> +static const struct acpi_device_id privacy_acpi_device_ids[] = {
> + {"PNP0C09", 0},
> + {"", 0},
> +};
> +MODULE_DEVICE_TABLE(acpi, privacy_acpi_device_ids);
> +
> +static struct platform_driver privacy_platform_driver = {
> + .driver = {
> + .name = PRIVACY_PlATFORM_NAME,
> + .acpi_match_table = ACPI_PTR(privacy_acpi_device_ids),
> + },
> + .probe = privacy_acpi_probe,
> + .remove = privacy_acpi_remove,
> +};
> +
> +int privacy_acpi_init(void)
> +{
> + int err;
> +
> + err = platform_driver_register(&privacy_platform_driver);
> + if (err)
> + return err;
> +
> + privacy_acpi_pdev = platform_device_register_simple(
> + PRIVACY_PlATFORM_NAME, -1, NULL, 0);
> + if (IS_ERR(privacy_acpi_pdev)) {
> + err = PTR_ERR(privacy_acpi_pdev);
> + goto err_platform;
> + }
> + return 0;
> +
> +err_platform:
> + platform_driver_unregister(&privacy_platform_driver);
> + return err;
> +}
Maybe I'm missing something obvious, but I do believe this is overly complicated.
I don't see why you cannot check the ACPI path, if it exists, register
a platform device, and then register the led to that device? The whole platform driver
part could've been avoided as far as I see.
I'm also wondering if the ACPI path is enough to decide undoubtedly that this
is indeed a compatible device.
> +
> +void privacy_acpi_cleanup(void)
> +{
> + platform_driver_unregister(&privacy_platform_driver);
> +}
The platform device is not cleaned up.
> +
> +MODULE_AUTHOR("Perry Yuan <perry_yuan@xxxxxxxx>");
> +MODULE_DESCRIPTION("DELL Privacy ACPI Driver");
> +MODULE_LICENSE("GPL");
> +
> diff --git a/drivers/platform/x86/dell-privacy-wmi.c b/drivers/platform/x86/dell-privacy-wmi.c
> new file mode 100644
> index 000000000000..6c36b7ec44c6
> --- /dev/null
> +++ b/drivers/platform/x86/dell-privacy-wmi.c
> @@ -0,0 +1,259 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Dell privacy notification driver
> + *
> + * Copyright (C) 2021 Dell Inc. All Rights Reserved.
> + */
> +
> +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> +
> +#include <linux/acpi.h>
> +#include <linux/input.h>
> +#include <linux/input/sparse-keymap.h>
> +#include <linux/list.h>
> +#include <linux/module.h>
> +#include <linux/wmi.h>
> +#include "dell-privacy-wmi.h"
> +
> +#define DELL_PRIVACY_GUID "6932965F-1671-4CEB-B988-D3AB0A901919"
> +#define MICROPHONE_STATUS BIT(0)
> +#define CAMERA_STATUS BIT(1)
> +#define PRIVACY_SCREEN_STATUS BIT(2)
`#include <linux/bits.h>`?
> +
> +static int privacy_valid = -EPROBE_DEFER;
> +static LIST_HEAD(wmi_list);
> +static DEFINE_MUTEX(list_mutex);
What is the purpose of this list? At the moment I can't really see it.
> +
> +struct privacy_wmi_data {
> + struct input_dev *input_dev;
> + struct wmi_device *wdev;
> + struct list_head list;
> + u32 features_present;
> + u32 last_status;
`last_status` and `features_present` are there for no actual benefit.
> +};
> +
> +/*
> + * Keymap for WMI Privacy events of type 0x0012
> + */
> +static const struct key_entry dell_wmi_keymap_type_0012[] = {
> + /* Privacy MIC Mute */
> + { KE_KEY, 0x0001, { KEY_MICMUTE } },
> + /* Privacy Camera Mute */
> + { KE_SW, 0x0002, { SW_CAMERA_LENS_COVER } },
I see the calloc trick later to avoid writing KE_END, but I still think it'd be
better if there was an explicit KE_END entry.
> +};
> +
> +bool dell_privacy_valid(void)
> +{
> + bool ret;
> +
> + mutex_lock(&list_mutex);
> + ret = wmi_has_guid(DELL_PRIVACY_GUID);
> + if (!ret){
> + return -ENODEV;
The functions returns `bool`.
> + }
> + ret = privacy_valid;
I'm not sure if it's a good idea to just plainly assign an `int` to a `bool`.
> + mutex_unlock(&list_mutex);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(dell_privacy_valid);
Instead of always querying for the presence of the WMI GUID, wouldn't a single
atomic_t or similar be sufficient?
> +
> +void dell_privacy_process_event(int type, int code, int status)
> +{
> + struct privacy_wmi_data *priv;
> + const struct key_entry *key;
> +
> + mutex_lock(&list_mutex);
> + priv = list_first_entry_or_null(&wmi_list,
> + struct privacy_wmi_data,
> + list);
> + if (priv == NULL) {
`if (!priv)`
> + pr_err("dell privacy priv is NULL\n");
> + goto error;
> + }
> +
> + key = sparse_keymap_entry_from_scancode(priv->input_dev, (type << 16)|code);
> + if (!key) {
> + dev_dbg(&priv->wdev->dev, "Unknown key with type 0x%04x and code 0x%04x pressed\n",
> + type, code);
> + goto error;
> + }
> +
> + switch (code) {
> + case DELL_PRIVACY_TYPE_AUDIO: /* Mic mute */
> + priv->last_status = status;
> + sparse_keymap_report_entry(priv->input_dev, key, 1, true);
> + break;
> + case DELL_PRIVACY_TYPE_CAMERA: /* Camera mute */
> + priv->last_status = status;
> + sparse_keymap_report_entry(priv->input_dev, key, 1, true);
> + break;
> + default:
> + dev_dbg(&priv->wdev->dev, "unknown event type %u /%u",
A couple lines above hexadecimal format and capitalization is used.
> + type, code);
> + }
> +error:
> + mutex_unlock(&list_mutex);
> + return;
> +}
> +EXPORT_SYMBOL_GPL(dell_privacy_process_event);
> [...]
> +static int dell_privacy_wmi_probe(struct wmi_device *wdev, const void *context)
> +{
> + struct privacy_wmi_data *priv;
> + struct key_entry *keymap;
> + int ret, i, pos = 0;
> +
> + priv = devm_kzalloc(&wdev->dev, sizeof(struct privacy_wmi_data),
> + GFP_KERNEL);
`sizeof(*priv)`
> + if (!priv)
> + return -ENOMEM;
> +
> + /* create evdev passing interface */
> + priv->input_dev = devm_input_allocate_device(&wdev->dev);
> + if (!priv->input_dev)
> + return -ENOMEM;
> +
> + __set_bit(EV_KEY, priv->input_dev->evbit);
> + __set_bit(KEY_MICMUTE, priv->input_dev->keybit);
> + __set_bit(EV_MSC, priv->input_dev->evbit);
> + __set_bit(MSC_SCAN, priv->input_dev->mscbit);
`sparse_keymap_setup()` takes care of this.
> + keymap = kcalloc(
> + ARRAY_SIZE(dell_wmi_keymap_type_0012) +
> + 1,
> + sizeof(struct key_entry), GFP_KERNEL);
> + if (!keymap) {
> + ret = -ENOMEM;
> + goto err_free_dev;
> + }
> + for (i = 0; i < ARRAY_SIZE(dell_wmi_keymap_type_0012); i++) {
> + keymap[pos] = dell_wmi_keymap_type_0012[i];
> + keymap[pos].code |= (0x0012 << 16);
> + pos++;
> + }
I can't quite see why you need a copy of the entries. If the key codes are initialized
to the "correct" values, this can be avoided altogether.
> + ret = sparse_keymap_setup(priv->input_dev, keymap, NULL);
> + if (ret)
> + return ret;
> +
> + priv->input_dev->dev.parent = &wdev->dev;
> + priv->input_dev->name = "Dell Privacy Driver";
> + priv->input_dev->id.bustype = BUS_HOST;
> +
> + if (input_register_device(priv->input_dev)) {
> + pr_debug("input_register_device failed to register! \n");
> + return -ENODEV;
`keymap` is leaked here.
> + }
> +
> + priv->wdev = wdev;
> + dev_set_drvdata(&wdev->dev, priv);
> + mutex_lock(&list_mutex);
> + list_add_tail(&priv->list, &wmi_list);
> + privacy_valid = true;
> + if (get_current_status(wdev)) {
> + goto err_free_dev;
Mutex is not unlocked. And some steps are not undone.
> + }
> + mutex_unlock(&list_mutex);
> + kfree(keymap);
> + return 0;
> +
> +err_free_dev:
> + input_free_device(priv->input_dev);
> + kfree(keymap);
> + return ret;
> +}
> +
> +static int dell_privacy_wmi_remove(struct wmi_device *wdev)
> +{
> + struct privacy_wmi_data *priv = dev_get_drvdata(&wdev->dev);
> +
> + mutex_lock(&list_mutex);
> + list_del(&priv->list);
> + privacy_valid = -ENODEV;
> + mutex_unlock(&list_mutex);
> + return 0;
> +}
> +
> +static const struct wmi_device_id dell_wmi_privacy_wmi_id_table[] = {
> + { .guid_string = DELL_PRIVACY_GUID },
> + { },
> +};
> +
> +static struct wmi_driver dell_privacy_wmi_driver = {
> + .driver = {
> + .name = "dell-privacy",
> + },
> + .probe = dell_privacy_wmi_probe,
> + .remove = dell_privacy_wmi_remove,
> + .id_table = dell_wmi_privacy_wmi_id_table,
> +};
> +
> +static int __init init_dell_privacy(void)
> +{
> + int ret, wmi, acpi;
`int ret;` would've been enough. The preferred and prevalent style is:
```
int ret;
ret = step_1();
if (ret) {
pr_err(...);
goto undo_step_1;
}
ret = step_2();
if (ret) {
pr_err(...);
goto undo_step_2;
}
...
return 0;
undo_step_2:
...
undo_step_1:
....
return ret;
```
> +
> + wmi = wmi_driver_register(&dell_privacy_wmi_driver);
> + if (wmi) {
> + pr_debug("Failed to initialize privacy wmi driver: %d\n", wmi);
> + return wmi;
> + }
> +
> + acpi = privacy_acpi_init();
> + if (acpi) {
> + pr_debug("failed to initialize privacy wmi acpi driver: %d\n", acpi);
> + return acpi;
> + }
> +
> + return 0;
> +}
Even ignoring stylistic questions, the WMI driver is not unregistered if
`privacy_acpi_init()` fails, which is a bigger problem.
Even ignoring that, I'm not sure it's a good idea that a module that exports
symbols for others to use can fail to load.
> +
> +void exit_dell_privacy_wmi(void)
> +{
> + wmi_driver_unregister(&dell_privacy_wmi_driver);
> +}
At the moment I can't quite see the purpose of this function.
> +
> +static void __exit exit_dell_privacy(void)
> +{
> + privacy_acpi_cleanup();
> + exit_dell_privacy_wmi();
> +}
> +
> +module_init(init_dell_privacy);
> +module_exit(exit_dell_privacy);
> +
> +MODULE_DEVICE_TABLE(wmi, dell_wmi_privacy_wmi_id_table);
A couple lines above the `MODULE_DEVICE_TABLE` macro was invoked right after
the device table.
> +MODULE_AUTHOR("Perry Yuan <perry_yuan@xxxxxxxx>");
> +MODULE_DESCRIPTION("Dell Privacy WMI Driver");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/platform/x86/dell-privacy-wmi.h b/drivers/platform/x86/dell-privacy-wmi.h
> new file mode 100644
> index 000000000000..94af81d76e44
> --- /dev/null
> +++ b/drivers/platform/x86/dell-privacy-wmi.h
> @@ -0,0 +1,23 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Dell privacy notification driver
> + *
> + * Copyright (C) 2021 Dell Inc. All Rights Reserved.
> + */
> +
> +#ifndef _DELL_PRIVACY_WMI_H_
> +#define _DELL_PRIVACY_WMI_H_
> +#include <linux/wmi.h>
This include is not needed.
> +
> +bool dell_privacy_valid(void);
> +void dell_privacy_process_event(int type, int code, int status);
> +int privacy_acpi_init(void);
> +void privacy_acpi_cleanup(void);
These aren't prefixed by `dell_`?
> +
> +/* DELL Privacy Type */
> +enum {
> + DELL_PRIVACY_TYPE_UNKNOWN = 0x0,
> + DELL_PRIVACY_TYPE_AUDIO,
> + DELL_PRIVACY_TYPE_CAMERA,
> +};
> +#endif
> diff --git a/drivers/platform/x86/dell-wmi.c b/drivers/platform/x86/dell-wmi.c
> index bbdb3e860892..44bb74e4df86 100644
> --- a/drivers/platform/x86/dell-wmi.c
> +++ b/drivers/platform/x86/dell-wmi.c
> @@ -27,6 +27,7 @@
> #include <acpi/video.h>
> #include "dell-smbios.h"
> #include "dell-wmi-descriptor.h"
> +#include "dell-privacy-wmi.h"
>
> MODULE_AUTHOR("Matthew Garrett <mjg@xxxxxxxxxx>");
> MODULE_AUTHOR("Pali Rohár <pali@xxxxxxxxxx>");
> @@ -410,44 +411,57 @@ static void dell_wmi_notify(struct wmi_device *wdev,
> if (buffer_end > buffer_entry + buffer_entry[0] + 1)
> buffer_end = buffer_entry + buffer_entry[0] + 1;
>
> - while (buffer_entry < buffer_end) {
> -
> - len = buffer_entry[0];
> - if (len == 0)
> - break;
> -
> - len++;
> -
> - if (buffer_entry + len > buffer_end) {
> - pr_warn("Invalid length of WMI event\n");
> - break;
> - }
> -
> - pr_debug("Process buffer (%*ph)\n", len*2, buffer_entry);
> -
> - switch (buffer_entry[1]) {
> - case 0x0000: /* One key pressed or event occurred */
> - case 0x0012: /* Event with extended data occurred */
> - if (len > 2)
> - dell_wmi_process_key(wdev, buffer_entry[1],
> - buffer_entry[2]);
> - /* Extended data is currently ignored */
> - break;
> - case 0x0010: /* Sequence of keys pressed */
> - case 0x0011: /* Sequence of events occurred */
> - for (i = 2; i < len; ++i)
> - dell_wmi_process_key(wdev, buffer_entry[1],
> - buffer_entry[i]);
> - break;
> - default: /* Unknown event */
> - pr_info("Unknown WMI event type 0x%x\n",
> - (int)buffer_entry[1]);
> - break;
> - }
> -
> - buffer_entry += len;
> -
> - }
> + while (buffer_entry < buffer_end) {
> +
> + len = buffer_entry[0];
> + if (len == 0)
> + break;
> +
> + len++;
> +
> + if (buffer_entry + len > buffer_end) {
> + pr_warn("Invalid length of WMI event\n");
> + break;
> + }
> +
> + pr_debug("Process buffer (%*ph)\n", len*2, buffer_entry);
> +
> + switch (buffer_entry[1]) {
> + case 0x0000: /* One key pressed or event occurred */
> + if (len > 2)
> + dell_wmi_process_key(wdev, buffer_entry[1],
> + buffer_entry[2]);
> + break;
> + case 0x0010: /* Sequence of keys pressed */
> + case 0x0011: /* Sequence of events occurred */
> + for (i = 2; i < len; ++i)
> + dell_wmi_process_key(wdev, buffer_entry[1],
> + buffer_entry[i]);
> + break;
> + case 0x0012:
> +#if IS_ENABLED(CONFIG_DELL_PRIVACY)
> + if (dell_privacy_valid()) {
> + dell_privacy_process_event(buffer_entry[1], buffer_entry[3],
> + buffer_entry[4]);
> + } else {
> + if (len > 2)
> + dell_wmi_process_key(wdev, buffer_entry[1], buffer_entry[2]);
> + }
> +#else
> + /* Extended data is currently ignored */
> + if (len > 2)
> + dell_wmi_process_key(wdev, buffer_entry[1], buffer_entry[2]);
> +#endif
Wouldn't it be better if the header file provided a static inline definitions
for `dell_privacy_valid()` and `dell_privacy_process_event()` - if CONFIG_DELL_PRIVACY
is not enabled - that return false and do nothing, respectively? The same way
it's done in dell-smbios.h.
> + break;
> + default: /* Unknown event */
> + pr_info("Unknown WMI event type 0x%x\n",
> + (int)buffer_entry[1]);
> + break;
> + }
> +
> + buffer_entry += len;
> +
> + }
>
> }
> [...]
Regards,
Barnabás Pőcze