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Message-ID: <49d3ed29-b542-483b-969c-6b674a8ab0ca@redhat.com>
Date: Tue, 28 May 2024 10:26:12 +0200
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MIME-Version: 1.0
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Subject: Re: [PATCH] hid-asus: use hid for brightness control on keyboard
To: "Luke D. Jones" <luke@ljones.dev>, jikos@kernel.org
Cc: ilpo.jarvinen@linux.intel.com, corentin.chary@gmail.com,
 platform-driver-x86@vger.kernel.org, linux-kernel@vger.kernel.org,
 linux-input@vger.kernel.org, bentiss@kernel.org
References: <20240528013959.14661-1-luke@ljones.dev>
Content-Language: en-US, nl
From: Hans de Goede <hdegoede@redhat.com>
In-Reply-To: <20240528013959.14661-1-luke@ljones.dev>
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Hi Luke,

Thank you for the patch.

On 5/28/24 3:39 AM, Luke D. Jones wrote:
> On almost all ASUS ROG series laptops the MCU used for the USB keyboard
> also has a HID packet used for setting the brightness. This is usually
> the same as the WMI method. But in some laptops the WMI method either
> is missing or doesn't work, so we should default to the HID control.

It looks like you are doing 2 different things in 1 patch here,
please split this into 2 patches:

1. Use a different report_id for HID kbd backlight brightness control
on some models.

2. Skip registering the HID kbd backlight LED class device on some
models.

2 more remarks inline (below):

> 
> Signed-off-by: Luke D. Jones <luke@ljones.dev>
> ---
>  drivers/hid/hid-asus.c                     | 19 ++++++++++++-
>  drivers/platform/x86/asus-wmi.c            |  3 ++-
>  include/linux/platform_data/x86/asus-wmi.h | 31 ++++++++++++++++++++++
>  3 files changed, 51 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/hid/hid-asus.c b/drivers/hid/hid-asus.c
> index 02de2bf4f790..9389a3e733e3 100644
> --- a/drivers/hid/hid-asus.c
> +++ b/drivers/hid/hid-asus.c
> @@ -101,6 +101,7 @@ struct asus_kbd_leds {
>  	unsigned int brightness;
>  	spinlock_t lock;
>  	bool removed;
> +	int report_id;
>  };
>  
>  struct asus_touchpad_info {
> @@ -473,7 +474,7 @@ static enum led_brightness asus_kbd_backlight_get(struct led_classdev *led_cdev)
>  static void asus_kbd_backlight_work(struct work_struct *work)
>  {
>  	struct asus_kbd_leds *led = container_of(work, struct asus_kbd_leds, work);
> -	u8 buf[] = { FEATURE_KBD_REPORT_ID, 0xba, 0xc5, 0xc4, 0x00 };
> +	u8 buf[] = { led->report_id, 0xba, 0xc5, 0xc4, 0x00 };
>  	int ret;
>  	unsigned long flags;
>  
> @@ -492,12 +493,18 @@ static void asus_kbd_backlight_work(struct work_struct *work)
>   */
>  static bool asus_kbd_wmi_led_control_present(struct hid_device *hdev)
>  {
> +	struct asus_drvdata *drvdata = hid_get_drvdata(hdev);
>  	u32 value;
>  	int ret;
>  
>  	if (!IS_ENABLED(CONFIG_ASUS_WMI))
>  		return false;
>  
> +	if (drvdata->quirks & QUIRK_ROG_NKEY_KEYBOARD && asus_use_hidraw_led()) {
> +		hid_info(hdev, "using hidraw for asus::kbd_backlight\n");
> +		return false;
> +	}
> +

You call the helper for this asus_use_hidraw_led() but to me that suggests
that when the function returns true then userspace will control the brightness
to /dev/hidraw# where as what you mean is that the in kernel HID driver will
control the brightness. So please rename the helper to asus_use_hid_led()
and for the message use:

		hid_info(hdev, "using HID for asus::kbd_backlight\n");


>  	ret = asus_wmi_evaluate_method(ASUS_WMI_METHODID_DSTS,
>  				       ASUS_WMI_DEVID_KBD_BACKLIGHT, 0, &value);
>  	hid_dbg(hdev, "WMI backlight check: rc %d value %x", ret, value);
> @@ -507,6 +514,12 @@ static bool asus_kbd_wmi_led_control_present(struct hid_device *hdev)
>  	return !!(value & ASUS_WMI_DSTS_PRESENCE_BIT);
>  }
>  
> +static bool asus_kbd_is_input_led(void)
> +{
> +	return dmi_match(DMI_PRODUCT_NAME, "GU605")
> +	    || dmi_match(DMI_PRODUCT_NAME, "GA403");
> +}
> +
>  static int asus_kbd_register_leds(struct hid_device *hdev)
>  {
>  	struct asus_drvdata *drvdata = hid_get_drvdata(hdev);
> @@ -549,6 +562,10 @@ static int asus_kbd_register_leds(struct hid_device *hdev)
>  	if (!drvdata->kbd_backlight)
>  		return -ENOMEM;
>  
> +	drvdata->kbd_backlight->report_id = FEATURE_KBD_REPORT_ID;
> +	if (drvdata->quirks & QUIRK_ROG_NKEY_KEYBOARD && asus_kbd_is_input_led())
> +		drvdata->kbd_backlight->report_id = FEATURE_KBD_LED_REPORT_ID1;
> +
>  	drvdata->kbd_backlight->removed = false;
>  	drvdata->kbd_backlight->brightness = 0;
>  	drvdata->kbd_backlight->hdev = hdev;
> diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
> index 3f9b6285c9a6..a58df18a70ad 100644
> --- a/drivers/platform/x86/asus-wmi.c
> +++ b/drivers/platform/x86/asus-wmi.c
> @@ -1681,7 +1681,8 @@ static int asus_wmi_led_init(struct asus_wmi *asus)
>  			goto error;
>  	}
>  
> -	if (!kbd_led_read(asus, &led_val, NULL)) {
> +	if (!kbd_led_read(asus, &led_val, NULL) && !asus_use_hidraw_led()) {
> +		pr_info("using asus-wmi for asus::kbd_backlight\n");
>  		asus->kbd_led_wk = led_val;
>  		asus->kbd_led.name = "asus::kbd_backlight";
>  		asus->kbd_led.flags = LED_BRIGHT_HW_CHANGED;
> diff --git a/include/linux/platform_data/x86/asus-wmi.h b/include/linux/platform_data/x86/asus-wmi.h
> index 3eb5cd6773ad..79a50102440d 100644
> --- a/include/linux/platform_data/x86/asus-wmi.h
> +++ b/include/linux/platform_data/x86/asus-wmi.h
> @@ -160,4 +160,35 @@ static inline int asus_wmi_evaluate_method(u32 method_id, u32 arg0, u32 arg1,
>  }
>  #endif
>  
> +/* To be used by both hid-asus and asus-wmi to determine which controls kbd_brightness */
> +#if IS_REACHABLE(CONFIG_ASUS_WMI)

This should be IS_ENABLED() otherwise if hid-asus is builtin and
asus-wmi is a module then this will go to the #else when included
from hid-asus.c and thus always return true causing hid-asus to
always register the kbd_backlight LED class device.

> +static bool asus_use_hidraw_led(void)
> +{
> +	const char *product, *board;
> +
> +	product = dmi_get_system_info(DMI_PRODUCT_FAMILY);
> +	if (!product)
> +		return false;
> +
> +	/* These product ranges should all be using HID for keyboard LED */
> +	if (strstr(product, "ROG Zephyrus")
> +	|| strstr(product, "ROG Strix")
> +	|| strstr(product, "ROG Flow")
> +	|| strstr(product, "GA403")
> +	|| strstr(product, "GU605"))
> +		return true;
> +
> +	board = dmi_get_system_info(DMI_BOARD_NAME);
> +	if (!board)
> +		return false;
> +
> +	return strstr(board, "RC71L"); /* ROG Ally specific */
> +}
> +#else
> +static inline bool asus_use_hidraw_led(void)
> +{
> +	return true;
> +}
> +#endif
> +
>  #endif	/* __PLATFORM_DATA_X86_ASUS_WMI_H */

Regards,

Hans