linux-kernel - Re: [PATCH v2] HID: apple: Fix stuck function keys when using FN

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Message-ID: <CAHxFc3SXM6hkbpTGZCsWOk70tByHE8af59ftOBwahY4fL0Sz=g@mail.gmail.com>
Date:   Tue, 3 Sep 2019 20:33:34 +0200
From:   João Moreno <mail@...omoreno.com>
To:     Benjamin Tissoires <benjamin.tissoires@...hat.com>
Cc:     Jiri Kosina <jikos@...nel.org>,
        "open list:HID CORE LAYER" <linux-input@...r.kernel.org>,
        lkml <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2] HID: apple: Fix stuck function keys when using FN

Hi Benjamin,

On Tue, 3 Sep 2019 at 16:46, Benjamin Tissoires
<benjamin.tissoires@...hat.com> wrote:
>
> From: Joao Moreno <mail@...omoreno.com>
>
> This fixes an issue in which key down events for function keys would be
> repeatedly emitted even after the user has raised the physical key. For
> example, the driver fails to emit the F5 key up event when going through
> the following steps:
> - fnmode=1: hold FN, hold F5, release FN, release F5
> - fnmode=2: hold F5, hold FN, release F5, release FN
>
> The repeated F5 key down events can be easily verified using xev.
>
> Signed-off-by: Joao Moreno <mail@...omoreno.com>
> Co-developed-by: Benjamin Tissoires <benjamin.tissoires@...hat.com>
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@...hat.com>
> ---
>
> Hi Joao,
>
> last chance to pull back :)
>
> If you are still happy, I'll push this version
>
> Cheers,
> Benjamin
>

Looks great. Thanks a bunch for your help!

Cheers,
João

>  drivers/hid/hid-apple.c | 49 +++++++++++++++++++++++------------------
>  1 file changed, 28 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/hid/hid-apple.c b/drivers/hid/hid-apple.c
> index 81df62f48c4c..6ac8becc2372 100644
> --- a/drivers/hid/hid-apple.c
> +++ b/drivers/hid/hid-apple.c
> @@ -54,7 +54,6 @@ MODULE_PARM_DESC(swap_opt_cmd, "Swap the Option (\"Alt\") and Command (\"Flag\")
>  struct apple_sc {
>         unsigned long quirks;
>         unsigned int fn_on;
> -       DECLARE_BITMAP(pressed_fn, KEY_CNT);
>         DECLARE_BITMAP(pressed_numlock, KEY_CNT);
>  };
>
> @@ -181,6 +180,8 @@ static int hidinput_apple_event(struct hid_device *hid, struct input_dev *input,
>  {
>         struct apple_sc *asc = hid_get_drvdata(hid);
>         const struct apple_key_translation *trans, *table;
> +       bool do_translate;
> +       u16 code = 0;
>
>         if (usage->code == KEY_FN) {
>                 asc->fn_on = !!value;
> @@ -189,8 +190,6 @@ static int hidinput_apple_event(struct hid_device *hid, struct input_dev *input,
>         }
>
>         if (fnmode) {
> -               int do_translate;
> -
>                 if (hid->product >= USB_DEVICE_ID_APPLE_WELLSPRING4_ANSI &&
>                                 hid->product <= USB_DEVICE_ID_APPLE_WELLSPRING4A_JIS)
>                         table = macbookair_fn_keys;
> @@ -202,25 +201,33 @@ static int hidinput_apple_event(struct hid_device *hid, struct input_dev *input,
>                 trans = apple_find_translation (table, usage->code);
>
>                 if (trans) {
> -                       if (test_bit(usage->code, asc->pressed_fn))
> -                               do_translate = 1;
> -                       else if (trans->flags & APPLE_FLAG_FKEY)
> -                               do_translate = (fnmode == 2 && asc->fn_on) ||
> -                                       (fnmode == 1 && !asc->fn_on);
> -                       else
> -                               do_translate = asc->fn_on;
> -
> -                       if (do_translate) {
> -                               if (value)
> -                                       set_bit(usage->code, asc->pressed_fn);
> -                               else
> -                                       clear_bit(usage->code, asc->pressed_fn);
> -
> -                               input_event(input, usage->type, trans->to,
> -                                               value);
> -
> -                               return 1;
> +                       if (test_bit(trans->from, input->key))
> +                               code = trans->from;
> +                       else if (test_bit(trans->to, input->key))
> +                               code = trans->to;
> +
> +                       if (!code) {
> +                               if (trans->flags & APPLE_FLAG_FKEY) {
> +                                       switch (fnmode) {
> +                                       case 1:
> +                                               do_translate = !asc->fn_on;
> +                                               break;
> +                                       case 2:
> +                                               do_translate = asc->fn_on;
> +                                               break;
> +                                       default:
> +                                               /* should never happen */
> +                                               do_translate = false;
> +                                       }
> +                               } else {
> +                                       do_translate = asc->fn_on;
> +                               }
> +
> +                               code = do_translate ? trans->to : trans->from;
>                         }
> +
> +                       input_event(input, usage->type, code, value);
> +                       return 1;
>                 }
>
>                 if (asc->quirks & APPLE_NUMLOCK_EMULATION &&
> --
> 2.19.2
>