Re: [PATCH 1/7] hid-asus: Fix up Zenbook Duo report descriptors

[Nathan Chancellor <nathan@kernel.org>]

Hi Paolo,

On Wed, May 13, 2026 at 06:32:42PM +0200, Paolo Pisati wrote:
> From: Joshua Leivenzon <hacker1024@users.sourceforge.net>
> 
> This is similar to the T100CHI/T90CHI keyboard dock fix.
> Without it, all reports log:
> 
> Unmapped Asus vendor usagepage code 0x76
> 
> Signed-off-by: Joshua Leivenzon <hacker1024@users.sourceforge.net>
> ---
>  drivers/hid/hid-asus.c | 13 +++++++++----
>  1 file changed, 9 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/hid/hid-asus.c b/drivers/hid/hid-asus.c
> index 3f5e96900b67a..ce246efba74d3 100644
> --- a/drivers/hid/hid-asus.c
> +++ b/drivers/hid/hid-asus.c
> @@ -99,6 +99,7 @@ MODULE_DESCRIPTION("Asus HID Keyboard and TouchPad");
>  #define QUIRK_ROG_CLAYMORE_II_KEYBOARD	BIT(12)
>  #define QUIRK_ROG_ALLY_XPAD		BIT(13)
>  #define QUIRK_HID_FN_LOCK		BIT(14)
> +#define QUIRK_ZENBOOK_DUO_KEYBOARD	BIT(15)
>  
>  #define I2C_KEYBOARD_QUIRKS			(QUIRK_FIX_NOTEBOOK_REPORT | \
>  						 QUIRK_NO_INIT_REPORTS | \
> @@ -1384,17 +1385,20 @@ static const __u8 *asus_report_fixup(struct hid_device *hdev, __u8 *rdesc,
>  		hid_info(hdev, "Fixing up Asus T100 keyb report descriptor\n");
>  		rdesc[74] &= ~HID_MAIN_ITEM_CONSTANT;
>  	}
> -	/* For the T100CHI/T90CHI keyboard dock */
> -	if (drvdata->quirks & (QUIRK_T100CHI | QUIRK_T90CHI)) {
> +	/* For the T100CHI/T90CHI keyboard dock and Zenbook Duo 2024+ keyboards */
> +	if (drvdata->quirks & (QUIRK_T100CHI | QUIRK_T90CHI | QUIRK_ZENBOOK_DUO_KEYBOARD)) {
>  		int rsize_orig;
>  		int offs;
>  
>  		if (drvdata->quirks & QUIRK_T100CHI) {
>  			rsize_orig = 403;
>  			offs = 388;
> -		} else {
> +		} else if (drvdata->quirks & QUIRK_T90CHI) {
>  			rsize_orig = 306;
>  			offs = 291;
> +		} else if (drvdata->quirks & QUIRK_ZENBOOK_DUO_KEYBOARD) {
> +			rsize_orig = 257;
> +			offs = 176;
>  		}

The way this if block is now written will cause a clang warning:

  https://lore.kernel.org/202606110526.QfgiXQTQ-lkp@intel.com/

It is obviously a false positive since we know one of those branches
will be taken from the parent if statement's condition.

Consider keeping the else, maybe with a comment, to make it clear to
both humans and the compiler that all cases are covered?

  } else { /* QUIRK_ZENBOOK_DUO_KEYBOARD */
    rsize_orig = 257;
    offs = 176;
  }

>  		/*
> @@ -1414,7 +1418,8 @@ static const __u8 *asus_report_fixup(struct hid_device *hdev, __u8 *rdesc,
>  
>  			hid_info(hdev, "Fixing up %s keyb report descriptor\n",
>  				drvdata->quirks & QUIRK_T100CHI ?
> -				"T100CHI" : "T90CHI");
> +				"T100CHI" : drvdata->quirks & QUIRK_T90CHI ?
> +				"T90CHI" : "ZENBOOK DUO");
>  
>  			memcpy(new_rdesc, rdesc, rsize_orig);
>  			*rsize = rsize_orig + 1;
> -- 
> 2.53.0
> 

-- 
Cheers,
Nathan