[PATCH] HID: asus: fix touchpad multitouch initialization regression

[PATCH] HID: asus: fix touchpad multitouch initialization regression

[PANZ]

In Linux 7.1, commit 7253091766de ("HID: asus: do not abort probe when
not necessary")
and commit 0919db9f3583 ("HID: asus: always fully initialize devices")
introduced regressions in the probe sequence for ASUS I2C/HID touchpads
(such as on the ASUS E200HA):

1. asus_start_multitouch() was placed inside the claimed input check block:
     if (drvdata->input && (hdev->claimed & HID_CLAIMED_INPUT))
   On ASUS touchpads, (hdev->claimed & HID_CLAIMED_INPUT) evaluates to
   false during asus_probe(), skipping asus_start_multitouch().

2. The asus_report_id_init loop in asus_probe() was executed unconditionally
   for all devices, which sends keyboard initialization feature requests
   (asus_kbd_init) to touchpad endpoints, corrupting touchpad probe state.

This patch fixes both issues by:
- Skipping keyboard report initialization for touchpad devices (!drvdata->tp).
- Moving asus_start_multitouch() outside the claimed input check block so
  multitouch initialization is always executed for touchpads.

Tested on ASUS E200HA (where touchpad functionality is fully restored)
and ASUS VivoBook Flip 14 TP401MA (confirming zero regressions).

Fixes: 7253091766de ("HID: asus: do not abort probe when not necessary")
Fixes: 0919db9f3583 ("HID: asus: always fully initialize devices")
Cc: stable@vger.kernel.org
Signed-off-by: ppanzenboeck <panz.development@gmail.com>
---
 drivers/hid/hid-asus.c | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/drivers/hid/hid-asus.c b/drivers/hid/hid-asus.c
index 3f5e96900b67..7f19ca1e5a1b 100644
--- a/drivers/hid/hid-asus.c
+++ b/drivers/hid/hid-asus.c
@@ -1294,12 +1294,14 @@ static int asus_probe(struct hid_device *hdev,
const struct hid_device_id *id)
  return ret;
  }

- for (int r = 0; r < ARRAY_SIZE(asus_report_id_init); r++) {
- if (asus_has_report_id(hdev, asus_report_id_init[r])) {
- ret = asus_kbd_init(hdev, asus_report_id_init[r]);
- if (ret < 0)
- hid_warn(hdev, "Failed to initialize 0x%x: %d.\n",
- asus_report_id_init[r], ret);
+ if (!drvdata->tp) {
+ for (int r = 0; r < ARRAY_SIZE(asus_report_id_init); r++) {
+ if (asus_has_report_id(hdev, asus_report_id_init[r])) {
+ ret = asus_kbd_init(hdev, asus_report_id_init[r]);
+ if (ret < 0)
+ hid_warn(hdev, "Failed to initialize 0x%x: %d.\n",
+ asus_report_id_init[r], ret);
+ }
  }
  }

@@ -1327,12 +1329,12 @@ static int asus_probe(struct hid_device *hdev,
const struct hid_device_id *id)
  drvdata->input->name = "Asus TouchPad";
  else
  drvdata->input->name = "Asus Keyboard";
+ }

- if (drvdata->tp) {
- ret = asus_start_multitouch(hdev);
- if (ret)
- goto err_stop_hw;
- }
+ if (drvdata->tp) {
+ ret = asus_start_multitouch(hdev);
+ if (ret)
+ goto err_stop_hw;
  }

  return 0;
-- 
2.47.0

Re: [PATCH] HID: asus: fix touchpad multitouch initialization regression

[Greg KH]

On Tue, Aug 18, 2026 at 10:25:27AM +0200, PANZ wrote:
> In Linux 7.1, commit 7253091766de ("HID: asus: do not abort probe when
> not necessary")
> and commit 0919db9f3583 ("HID: asus: always fully initialize devices")
> introduced regressions in the probe sequence for ASUS I2C/HID touchpads
> (such as on the ASUS E200HA):
> 
> 1. asus_start_multitouch() was placed inside the claimed input check block:
>      if (drvdata->input && (hdev->claimed & HID_CLAIMED_INPUT))
>    On ASUS touchpads, (hdev->claimed & HID_CLAIMED_INPUT) evaluates to
>    false during asus_probe(), skipping asus_start_multitouch().
> 
> 2. The asus_report_id_init loop in asus_probe() was executed unconditionally
>    for all devices, which sends keyboard initialization feature requests
>    (asus_kbd_init) to touchpad endpoints, corrupting touchpad probe state.
> 
> This patch fixes both issues by:
> - Skipping keyboard report initialization for touchpad devices (!drvdata->tp).
> - Moving asus_start_multitouch() outside the claimed input check block so
>   multitouch initialization is always executed for touchpads.
> 
> Tested on ASUS E200HA (where touchpad functionality is fully restored)
> and ASUS VivoBook Flip 14 TP401MA (confirming zero regressions).
> 
> Fixes: 7253091766de ("HID: asus: do not abort probe when not necessary")
> Fixes: 0919db9f3583 ("HID: asus: always fully initialize devices")
> Cc: stable@vger.kernel.org
> Signed-off-by: ppanzenboeck <panz.development@gmail.com>


Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
a patch that has triggered this response.  He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created.  Hopefully you will not take offence and will fix the problem
in your patch and resubmit it so that it can be accepted into the Linux
kernel tree.

You are receiving this message because of the following common error(s)
as indicated below:

- Your patch is malformed (tabs converted to spaces, linewrapped, etc.)
  and can not be applied.  Please read the file,
  Documentation/process/email-clients.rst in order to fix this.

- It looks like you did not use your "real" name for the patch on either
  the Signed-off-by: line, or the From: line (both of which have to
  match).  Please read the kernel file,
  Documentation/process/submitting-patches.rst for how to do this
  correctly.

If you wish to discuss this problem further, or you have questions about
how to resolve this issue, please feel free to respond to this email and
Greg will reply once he has dug out from the pending patches received
from other developers.

thanks,

greg k-h's patch email bot

[PATCH] HID: asus: fix touchpad multitouch initialization regression

[Panz Dev]

In Linux 7.1, commit 7253091766de ("HID: asus: do not abort probe when not necessary")
and commit 0919db9f3583 ("HID: asus: always fully initialize devices")
introduced regressions in the probe sequence for ASUS I2C/HID touchpads
(such as on the ASUS E200HA):

1. asus_start_multitouch() was placed inside the claimed input check block:
     if (drvdata->input && (hdev->claimed & HID_CLAIMED_INPUT))
   On ASUS touchpads, (hdev->claimed & HID_CLAIMED_INPUT) evaluates to
   false during asus_probe(), skipping asus_start_multitouch().

2. The asus_report_id_init loop in asus_probe() was executed unconditionally
   for all devices, which sends keyboard initialization feature requests
   (asus_kbd_init) to touchpad endpoints, corrupting touchpad probe state.

This patch fixes both issues by:
- Skipping keyboard report initialization for touchpad devices (!drvdata->tp).
- Moving asus_start_multitouch() outside the claimed input check block so
  multitouch initialization is always executed for touchpads.

Tested on ASUS E200HA (where touchpad functionality is fully restored)
and ASUS VivoBook Flip 14 TP401MA (confirming zero regressions).

Fixes: 7253091766de ("HID: asus: do not abort probe when not necessary")
Fixes: 0919db9f3583 ("HID: asus: always fully initialize devices")
Cc: stable@vger.kernel.org
Signed-off-by: Panz Dev <panz.development@gmail.com>
---
 drivers/hid/hid-asus.c | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/drivers/hid/hid-asus.c b/drivers/hid/hid-asus.c
index 3f5e96900b67..7f19ca1e5a1b 100644
--- a/drivers/hid/hid-asus.c
+++ b/drivers/hid/hid-asus.c
@@ -1294,12 +1294,14 @@ static int asus_probe(struct hid_device *hdev, const struct hid_device_id *id)
 		return ret;
 	}

-	for (int r = 0; r < ARRAY_SIZE(asus_report_id_init); r++) {
-		if (asus_has_report_id(hdev, asus_report_id_init[r])) {
-			ret = asus_kbd_init(hdev, asus_report_id_init[r]);
-			if (ret < 0)
-				hid_warn(hdev, "Failed to initialize 0x%x: %d.\n",
-					 asus_report_id_init[r], ret);
+	if (!drvdata->tp) {
+		for (int r = 0; r < ARRAY_SIZE(asus_report_id_init); r++) {
+			if (asus_has_report_id(hdev, asus_report_id_init[r])) {
+				ret = asus_kbd_init(hdev, asus_report_id_init[r]);
+				if (ret < 0)
+					hid_warn(hdev, "Failed to initialize 0x%x: %d.\n",
+						 asus_report_id_init[r], ret);
+			}
 		}
 	}

@@ -1327,12 +1329,12 @@ static int asus_probe(struct hid_device *hdev, const struct hid_device_id *id)
 			drvdata->input->name = "Asus TouchPad";
 		else
 			drvdata->input->name = "Asus Keyboard";
+	}

-		if (drvdata->tp) {
-			ret = asus_start_multitouch(hdev);
-			if (ret)
-				goto err_stop_hw;
-		}
+	if (drvdata->tp) {
+		ret = asus_start_multitouch(hdev);
+		if (ret)
+			goto err_stop_hw;
 	}

 	return 0;
-- 
2.47.0

Re: [PATCH] HID: asus: fix touchpad multitouch initialization regression

[Denis Benato]

On 8/18/26 10:56, Panz Dev wrote:
> In Linux 7.1, commit 7253091766de ("HID: asus: do not abort probe when not necessary")
> and commit 0919db9f3583 ("HID: asus: always fully initialize devices")
> introduced regressions in the probe sequence for ASUS I2C/HID touchpads
> (such as on the ASUS E200HA):
>
> 1. asus_start_multitouch() was placed inside the claimed input check block:
>      if (drvdata->input && (hdev->claimed & HID_CLAIMED_INPUT))
>    On ASUS touchpads, (hdev->claimed & HID_CLAIMED_INPUT) evaluates to
>    false during asus_probe(), skipping asus_start_multitouch().
>
> 2. The asus_report_id_init loop in asus_probe() was executed unconditionally
>    for all devices, which sends keyboard initialization feature requests
>    (asus_kbd_init) to touchpad endpoints, corrupting touchpad probe state.
>
> This patch fixes both issues by:
> - Skipping keyboard report initialization for touchpad devices (!drvdata->tp).
> - Moving asus_start_multitouch() outside the claimed input check block so
>   multitouch initialization is always executed for touchpads.
>
> Tested on ASUS E200HA (where touchpad functionality is fully restored)
> and ASUS VivoBook Flip 14 TP401MA (confirming zero regressions).
Hi,

thanks for this! I forgot to exclude touchpads from that init sequence.
> Fixes: 7253091766de ("HID: asus: do not abort probe when not necessary")
> Fixes: 0919db9f3583 ("HID: asus: always fully initialize devices")
> Cc: stable@vger.kernel.org
> Signed-off-by: Panz Dev <panz.development@gmail.com>
> ---
>  drivers/hid/hid-asus.c | 22 ++++++++++++----------
>  1 file changed, 12 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/hid/hid-asus.c b/drivers/hid/hid-asus.c
> index 3f5e96900b67..7f19ca1e5a1b 100644
> --- a/drivers/hid/hid-asus.c
> +++ b/drivers/hid/hid-asus.c
> @@ -1294,12 +1294,14 @@ static int asus_probe(struct hid_device *hdev, const struct hid_device_id *id)
>  		return ret;
>  	}
>
> -	for (int r = 0; r < ARRAY_SIZE(asus_report_id_init); r++) {
> -		if (asus_has_report_id(hdev, asus_report_id_init[r])) {
> -			ret = asus_kbd_init(hdev, asus_report_id_init[r]);
> -			if (ret < 0)
> -				hid_warn(hdev, "Failed to initialize 0x%x: %d.\n",
> -					 asus_report_id_init[r], ret);
> +	if (!drvdata->tp) {
> +		for (int r = 0; r < ARRAY_SIZE(asus_report_id_init); r++) {
> +			if (asus_has_report_id(hdev, asus_report_id_init[r])) {
> +				ret = asus_kbd_init(hdev, asus_report_id_init[r]);
> +				if (ret < 0)
> +					hid_warn(hdev, "Failed to initialize 0x%x: %d.\n",
> +						 asus_report_id_init[r], ret);
> +			}
>  		}
>  	}
>
> @@ -1327,12 +1329,12 @@ static int asus_probe(struct hid_device *hdev, const struct hid_device_id *id)
>  			drvdata->input->name = "Asus TouchPad";
>  		else
>  			drvdata->input->name = "Asus Keyboard";
> +	}
>
> -		if (drvdata->tp) {
> -			ret = asus_start_multitouch(hdev);
> -			if (ret)
> -				goto err_stop_hw;
> -		}
> +	if (drvdata->tp) {
> +		ret = asus_start_multitouch(hdev);
> +		if (ret)
> +			goto err_stop_hw;
>  	}
I think this will re-introduce the security vulnerability fixed in the commit that led to me
creating the "HID: asus: do not abort probe when unnecessary"...

Furthermore if that drvdata->input && (hdev->claumed & HID_CLAIMED_INPUT) doesn't
evaluate to true it would be useful to know what part is false and that code that prevents
null/invalid dereference is wrong, and since I tried touching it the least possible it means
there is also the need to change the && back into ||, but that would undo the "keep the
proper name of the device" for keyboards...

With these in mind would you want to try fixing them all at once?
>  	return 0;