Re: [PATCH v6 1/7] HID: asus: refactor init sequence per spec

Ilpo Järvinen
2025-10-15T10:53:41Z

On Mon, 13 Oct 2025, Antheas Kapenekakis wrote:

> Currently, asus_kbd_init() uses a reverse engineered init sequence
> from Windows, which contains the handshakes from multiple programs.
> Keep the main one, which is 0x5a (meant for brightness drivers).
>
> In addition, perform a get_response and check if the response is the
> same. To avoid regressions, print an error if the response does not
> match instead of rejecting device.

I'm none the wiser on "why?" question after reading all this. Please
describe the change properly. Besides, you do many thing changes which are
not mentioned here at all.

And what "spec" is the one you mention in the shortlog?

> Then, refactor asus_kbd_get_functions() to use the same ID it is called
> with, instead of hardcoding it to 0x5a so that it may be used for 0x0d
> in the future.

Can this be in own patch?

> Signed-off-by: Antheas Kapenekakis <lkml@antheas.dev>
> ---
> drivers/hid/hid-asus.c | 91 ++++++++++++++++++++++--------------------
> 1 file changed, 48 insertions(+), 43 deletions(-)
>
> diff --git a/drivers/hid/hid-asus.c b/drivers/hid/hid-asus.c
> index a444d41e53b6..d0c783df99bc 100644
> --- a/drivers/hid/hid-asus.c
> +++ b/drivers/hid/hid-asus.c
> @@ -48,7 +48,7 @@ MODULE_DESCRIPTION("Asus HID Keyboard and TouchPad");
> #define FEATURE_REPORT_ID 0x0d
> #define INPUT_REPORT_ID 0x5d
> #define FEATURE_KBD_REPORT_ID 0x5a
> -#define FEATURE_KBD_REPORT_SIZE 16
> +#define FEATURE_KBD_REPORT_SIZE 64
> #define FEATURE_KBD_LED_REPORT_ID1 0x5d
> #define FEATURE_KBD_LED_REPORT_ID2 0x5e
>
> @@ -393,14 +393,37 @@ static int asus_kbd_set_report(struct hid_device *hdev, const u8 *buf, size_t bu
>
> static int asus_kbd_init(struct hid_device *hdev, u8 report_id)
> {
> - const u8 buf[] = { report_id, 0x41, 0x53, 0x55, 0x53, 0x20, 0x54,
> - 0x65, 0x63, 0x68, 0x2e, 0x49, 0x6e, 0x63, 0x2e, 0x00 };
> + /*
> + * The handshake is first sent as a set_report, then retrieved
> + * from a get_report. They should be equal.
> + */
> + const u8 buf[] = { report_id, 0x41, 0x53, 0x55, 0x53, 0x20,
> + 0x54, 0x65, 0x63, 0x68, 0x2e, 0x49, 0x6e, 0x63, 0x2e, 0x00 };

Why was layout of this changed?

> + u8 *readbuf;
> int ret;
>
> ret = asus_kbd_set_report(hdev, buf, sizeof(buf));
> - if (ret < 0)
> - hid_err(hdev, "Asus failed to send init command: %d\n", ret);
> + if (ret < 0) {
> + hid_err(hdev, "Asus failed to send handshake: %d\n", ret);
> + return ret;
> + }
> +
> + readbuf = kzalloc(FEATURE_KBD_REPORT_SIZE, GFP_KERNEL);
> + if (!readbuf)
> + return -ENOMEM;
> +
> + ret = hid_hw_raw_request(hdev, report_id, readbuf,
> + FEATURE_KBD_REPORT_SIZE, HID_FEATURE_REPORT,
> + HID_REQ_GET_REPORT);
> + if (ret < 0) {
> + hid_err(hdev, "Asus failed to receive handshake ack: %d\n", ret);
> + } else if (memcmp(readbuf, buf, sizeof(buf)) != 0) {
> + hid_warn(hdev, "Asus handshake returned invalid response: %*ph\n",
> + FEATURE_KBD_REPORT_SIZE, readbuf);
> + // Do not return error if handshake is wrong to avoid regressions

This driver so far is using only /* */ comments.

> + }
>
> + kfree(readbuf);
> return ret;
> }
>
> @@ -422,7 +445,7 @@ static int asus_kbd_get_functions(struct hid_device *hdev,
> if (!readbuf)
> return -ENOMEM;
>
> - ret = hid_hw_raw_request(hdev, FEATURE_KBD_REPORT_ID, readbuf,
> + ret = hid_hw_raw_request(hdev, report_id, readbuf,
> FEATURE_KBD_REPORT_SIZE, HID_FEATURE_REPORT,
> HID_REQ_GET_REPORT);
> if (ret < 0) {
> @@ -638,50 +661,32 @@ static int asus_kbd_register_leds(struct hid_device *hdev)
> unsigned char kbd_func;
> int ret;
>
> - if (drvdata->quirks & QUIRK_ROG_NKEY_KEYBOARD) {
> - /* Initialize keyboard */
> - ret = asus_kbd_init(hdev, FEATURE_KBD_REPORT_ID);
> - if (ret < 0)
> - return ret;
> -
> - /* The LED endpoint is initialised in two HID */
> - ret = asus_kbd_init(hdev, FEATURE_KBD_LED_REPORT_ID1);
> - if (ret < 0)
> - return ret;
> -
> - ret = asus_kbd_init(hdev, FEATURE_KBD_LED_REPORT_ID2);
> - if (ret < 0)
> - return ret;
> -
> - if (dmi_match(DMI_PRODUCT_FAMILY, "ProArt P16")) {
> - ret = asus_kbd_disable_oobe(hdev);
> - if (ret < 0)
> - return ret;
> - }
> -
> - if (drvdata->quirks & QUIRK_ROG_ALLY_XPAD) {
> - intf = to_usb_interface(hdev->dev.parent);
> - udev = interface_to_usbdev(intf);
> - validate_mcu_fw_version(hdev,
> - le16_to_cpu(udev->descriptor.idProduct));
> - }
> + ret = asus_kbd_init(hdev, FEATURE_KBD_REPORT_ID);
> + if (ret < 0)
> + return ret;
>
> - } else {
> - /* Initialize keyboard */
> - ret = asus_kbd_init(hdev, FEATURE_KBD_REPORT_ID);
> - if (ret < 0)
> - return ret;
> + /* Get keyboard functions */
> + ret = asus_kbd_get_functions(hdev, &kbd_func, FEATURE_KBD_REPORT_ID);
> + if (ret < 0)
> + return ret;
>
> - /* Get keyboard functions */
> - ret = asus_kbd_get_functions(hdev, &kbd_func, FEATURE_KBD_REPORT_ID);
> + if (dmi_match(DMI_PRODUCT_FAMILY, "ProArt P16")) {
> + ret = asus_kbd_disable_oobe(hdev);
> if (ret < 0)
> return ret;
> + }
>
> - /* Check for backlight support */
> - if (!(kbd_func & SUPPORT_KBD_BACKLIGHT))
> - return -ENODEV;
> + if (drvdata->quirks & QUIRK_ROG_ALLY_XPAD) {
> + intf = to_usb_interface(hdev->dev.parent);
> + udev = interface_to_usbdev(intf);
> + validate_mcu_fw_version(
> + hdev, le16_to_cpu(udev->descriptor.idProduct));
> }
>
> + /* Check for backlight support */
> + if (!(kbd_func & SUPPORT_KBD_BACKLIGHT))
> + return -ENODEV;
> +
> drvdata->kbd_backlight = devm_kzalloc(&hdev->dev,
> sizeof(struct asus_kbd_leds),
> GFP_KERNEL);
>

--
i.