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Message-ID:
<CAGwozwG8nVOod4NTobc_8U-V9WqeZQPGwF9NO7Tjjo_DWu_3qg@mail.gmail.com>
Date: Sun, 23 Mar 2025 00:54:50 +0100
From: Antheas Kapenekakis <lkml@...heas.dev>
To: "Luke D. Jones" <luke@...nes.dev>
Cc: platform-driver-x86@...r.kernel.org, linux-input@...r.kernel.org,
linux-kernel@...r.kernel.org, Jiri Kosina <jikos@...nel.org>,
Benjamin Tissoires <bentiss@...nel.org>,
Corentin Chary <corentin.chary@...il.com>,
Hans de Goede <hdegoede@...hat.com>,
Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
Subject: Re: [PATCH v3 01/10] HID: asus: refactor init sequence per spec
On Sun, 23 Mar 2025 at 00:53, Antheas Kapenekakis <lkml@...heas.dev> wrote:
>
> On Sun, 23 Mar 2025 at 00:29, Luke D. Jones <luke@...nes.dev> wrote:
> >
> > On 23/03/25 12:05, Antheas Kapenekakis wrote:
> > > On Sat, 22 Mar 2025 at 23:01, Luke D. Jones <luke@...nes.dev> wrote:
> > >>
> > >> On 22/03/25 23:27, 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.
> > >>>
> > >>> 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.
> > >>>
> > >>> Signed-off-by: Antheas Kapenekakis <lkml@...heas.dev>
> > >>> ---
> > >>> drivers/hid/hid-asus.c | 82 +++++++++++++++++++++++-------------------
> > >>> 1 file changed, 46 insertions(+), 36 deletions(-)
> > >>>
> > >>> diff --git a/drivers/hid/hid-asus.c b/drivers/hid/hid-asus.c
> > >>> index 46e3e42f9eb5f..8d4df1b6f143b 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
> > >>>
> > >>> @@ -388,14 +388,41 @@ 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 };
> > >>> + /*
> > >>> + * Asus handshake identifying us as a driver (0x5A)
> > >>> + * 0x5A then ASCII for "ASUS Tech.Inc."
> > >>> + * 0x5D is for userspace Windows applications.
> > >>> + *
> > >>> + * The handshake is first sent as a set_report, then retrieved
> > >>> + * from a get_report to verify the response.
> > >>> + */
> > >>
> > >> This entire comment is not required, especially not the last paragraph.
> > >> From what I've seen in .dll reversing attempts there's no real
> > >> distinction from driver/app and it's simply an init/enable sequence
> > >> common to almost every ITE MCU that ASUS have used (slash, anime, Ally).
> > >>
> > >> Please remove.
> > >
> > > It is a context comment but can be removed.
> > >
> > >>> + const u8 buf[] = { report_id, 0x41, 0x53, 0x55, 0x53, 0x20,
> > >>> + 0x54, 0x65, 0x63, 0x68, 0x2e, 0x49, 0x6e, 0x63, 0x2e, 0x00 };
> > >>> + 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_err(hdev, "Asus handshake returned invalid response: %*ph\n",
> > >>> + FEATURE_KBD_REPORT_SIZE, readbuf);
> > >>> + // Do not return error if handshake is wrong to avoid regressions
> > >>> + }
> > >>> +
> > >>> + kfree(readbuf);
> > >>> return ret;
> > >>> }
> > >>>
> > >>> @@ -417,7 +444,7 @@ 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) {
> > >>> @@ -540,42 +567,25 @@ 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;
> > >>> + ret = asus_kbd_init(hdev, FEATURE_KBD_REPORT_ID);
> > >>> + if (ret < 0)
> > >>> + return ret;
> > >>>
> > >>
> > >> I don't have any non-ROG equipment to test. There have been some cases
> > >> of Vivobook using the same MCU, but these otherwise used something else.
> > >> And the oldest hardware I have uses a 0x1866, which uses the same init
> > >> sequence but works with both 0x5A and 0x5D report ID for init (on same
> > >> endpoint). There are instances of other laptops that accept both 0x5A
> > >> and 0x5D, and some that have only 0x5D.
> > >
> > > The driver sets the brightness using 0x5a and accepts keyboard
> > > shortcuts only from 0x5a. Therefore it needs to init only with 0x5a.
> > >
> > > How would those laptops regress and in what way?
> > >
> >
> > The media keys fail to work (vol, mic, rog). Can you please accept that
> > I do know some laptops used only 0x5D, and these are older models,
> > around 5+ years. The only thing I have to go on is my memory
> > unfortunately, and I've been trying to find the concrete examples.
>
> I just looked at the history. Yeah it seems you added ID1 in 2020 with
> some other commands. But on the same commit you blocked 0x5d and 0x5e,
> so it means those keyboards use 0x5a to send keyboard events.
>
> Nevertheless, it is not worth looking up or risking regressions for
> old hardware. I will readd 0x5d, 0x5e for
> USB_DEVICE_ID_ASUSTEK_ROG_NKEY_KEYBOARD and
> USB_DEVICE_ID_ASUSTEK_ROG_NKEY_KEYBOARD2, since those are the ones you
> added the inits with.
>
> But I will still keep them off for the Z13 and Ally.
>
> By the way,
I guess I did not finish this. I was going to express some concern
about the Claymore keyboard. But it seems it does not have a backlight
quirk so it is ok
> Antheas
>
> > >> I think you will need to change this to try both 0x5A and 0x5D sorry.
> > >> The older models using 0x1854, 0x1869, 0x1866 PID may regress and
> > >> although I'm reasonably confident there won't be issues due to age of
> > >> those, it's not a risk I'm willing to take, I've spent all morning
> > >> trawling through archives of info and I can't actually verify this other
> > >> than from my memory.
> > >
> > > For devices that support RGB, only when RGB is set, 0x5D is initialized too.
> >
> > Sure. But as I've said above.. Please add both to init. It's only done
> > once, and it doesn't hurt anything plus doesn't risk regressing older
> > hardware.
> >
> > If I can get the proper evidence that only 0x5A is required I'm happy to
> > use only that, but until then I don't want that risk. And it's only a
> > small thing here.
> >
> > Cheers,
> > Luke.
> >
> > >
> > >> I mentioned 0x5E being used for some of the oddball devices like slash
> > >> and anime, don't worry about that one, it's a bridge that can be crossed
> > >> at a later time. But it does illustrate that other report ID have been
> > >> used for init.
> > >>
> > >> Otherwise the cleanup is good.
> > >>
> > >> No other comments required and I'll sign off with the above corrections.
> > >>
> > >> Cheers,
> > >> Luke
> > >>
> > >>> - if (dmi_match(DMI_PRODUCT_FAMILY, "ProArt P16")) {
> > >>> - ret = asus_kbd_disable_oobe(hdev);
> > >>> - 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;
> > >>> }
> > >>>
> > >>> + /* 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);
> > >>
> >
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