Re: [PATCH 1/3] dell_wmi: Support new hotkeys on the XPS 13 Skylake

["Pali Rohár" <pali.rohar@gmail.com>]

On Friday 13 November 2015 21:49:30 Andy Lutomirski wrote:
> The XPS 13 Skylake has an rfkill button and a switchvideomode button
> that aren't enumerated in the DMI table AFAICT.  Add a table listing
> extra un-enumerated hotkeys.  To avoid breaking things that worked
> before, these un-enumerated hotkeys won't be used if the DMI table
> maps them to something else.
> 

Do you have any (Dell) documentation which specify list of these wmi
codes send to dell-wmi driver?

> This also adds the Fn-lock key as a KE_IGNORE entry.
> 
> Signed-off-by: Andy Lutomirski <luto@kernel.org>
> ---
>  drivers/platform/x86/dell-wmi.c | 48 +++++++++++++++++++++++++++++++++++------
>  1 file changed, 41 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/platform/x86/dell-wmi.c b/drivers/platform/x86/dell-wmi.c
> index f2d77fe696ac..5be1abec4f64 100644
> --- a/drivers/platform/x86/dell-wmi.c
> +++ b/drivers/platform/x86/dell-wmi.c
> @@ -142,6 +142,16 @@ static const u16 bios_to_linux_keycode[256] __initconst = {
>  	0, 0, 0, 0, 0, 0, 0, 0, 0, KEY_PROG3
>  };
>  
> +/* These are applied if the hk table is present and doesn't override them. */
> +static const struct key_entry dell_wmi_extra_keymap[] __initconst = {
> +	/* Fn-lock -- no action is required by the kernel. */
> +	{ KE_IGNORE, 0x151, { KEY_RESERVED } },
> +
> +	/* Keys that need our help (on XPS 13 Skylake and maybe others. */
> +	{ KE_KEY, 0x152, { KEY_SWITCHVIDEOMODE } },
> +	{ KE_KEY, 0x153, { KEY_RFKILL } },

On more Dell laptops rfkill events are handed by ACPI driver
dell-rbtn.ko. Are you sure that dell-rbtn.ko does not send keypress
event and you really need it from dell-wmi? We already masked KEY_RFKILL
in dell-wmi to prevent double events...

> +};
> +
>  static struct input_dev *dell_wmi_input_dev;
>  
>  static void dell_wmi_process_key(int reported_key)
> @@ -300,9 +310,10 @@ static const struct key_entry * __init dell_wmi_prepare_new_keymap(void)
>  	int hotkey_num = (dell_bios_hotkey_table->header.length - 4) /
>  				sizeof(struct dell_bios_keymap_entry);
>  	struct key_entry *keymap;
> -	int i;
> +	int i, pos = 0, num_bios_keys;
>  
> -	keymap = kcalloc(hotkey_num + 1, sizeof(struct key_entry), GFP_KERNEL);
> +	keymap = kcalloc(hotkey_num + ARRAY_SIZE(dell_wmi_extra_keymap),
> +			 sizeof(struct key_entry), GFP_KERNEL);
>  	if (!keymap)
>  		return NULL;
>  
> @@ -314,14 +325,37 @@ static const struct key_entry * __init dell_wmi_prepare_new_keymap(void)
>  				    KEY_RESERVED;
>  
>  		if (keycode == KEY_KBDILLUMTOGGLE)
> -			keymap[i].type = KE_IGNORE;
> +			keymap[pos].type = KE_IGNORE;
>  		else
> -			keymap[i].type = KE_KEY;
> -		keymap[i].code = bios_entry->scancode;
> -		keymap[i].keycode = keycode;
> +			keymap[pos].type = KE_KEY;
> +		keymap[pos].code = bios_entry->scancode;
> +		keymap[pos].keycode = keycode;
> +
> +		pos++;
> +	}
> +
> +	num_bios_keys = pos;
> +
> +	for (i = 0; i < ARRAY_SIZE(dell_wmi_extra_keymap); i++) {
> +		int j;
> +
> +		/*
> +		 * Check if we've already found this scancode.  This takes
> +		 * quadratic time, but it doesn't matter unless the list
> +		 * of extra keys gets very long.
> +		 */
> +		for (j = 0; j < num_bios_keys; j++)
> +			if (keymap[j].code == dell_wmi_extra_keymap[i].code)
> +				goto skip;

Rather move this code into separate boolean function and for return
value here. This will prevent using hacky goto...

> +
> +		keymap[pos] = dell_wmi_extra_keymap[i];
> +		pos++;
> +
> +skip:
> +		;
>  	}
>  
> -	keymap[hotkey_num].type = KE_END;
> +	keymap[pos].type = KE_END;
>  
>  	return keymap;
>  }

-- 
Pali Rohár
pali.rohar@gmail.com