linux-kernel - Re: [PATCH v2 09/24] input: Port hid-dr to ff-memless-next

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Message-ID: <1398260463.32091.5.camel@linux-fkkt.site>
Date:	Wed, 23 Apr 2014 15:41:03 +0200
From:	Oliver Neukum <oneukum@...e.de>
To:	Michal Malý <madcatxster@...oid-pointer.net>
Cc:	linux-input@...r.kernel.org, linux-kernel@...r.kernel.org,
	dmitry.torokhov@...il.com, jkosina@...e.cz, elias.vds@...il.com,
	anssi.hannula@....fi, simon@...gewell.org
Subject: Re: [PATCH v2 09/24] input: Port hid-dr to ff-memless-next

On Tue, 2014-04-22 at 15:59 +0200, Michal Malý wrote:
>  static int drff_play(struct input_dev *dev, void *data,
> -                                struct ff_effect *effect)
> +                       const struct mlnx_effect_command *command)
>  {
>         struct hid_device *hid = input_get_drvdata(dev);
>         struct drff_device *drff = data;
> +       const struct mlnx_rumble_force *rumble_force =
> &command->u.rumble_force;
>         int strong, weak;
>  
> -       strong = effect->u.rumble.strong_magnitude;
> -       weak = effect->u.rumble.weak_magnitude;
> +       strong = rumble_force->strong;
> +       weak = rumble_force->weak;
>  
>         dbg_hid("called with 0x%04x 0x%04x", strong, weak);
>  
> -       if (strong || weak) {
> -               strong = strong * 0xff / 0xffff;
> -               weak = weak * 0xff / 0xffff;
> -
> -               /* While reverse engineering this device, I found that
> when
> -                  this value is set, it causes the strong rumble to
> function
> -                  at a near maximum speed, so we'll bypass it. */
> -               if (weak == 0x0a)
> -                       weak = 0x0b;
> -
> -               drff->report->field[0]->value[0] = 0x51;
> -               drff->report->field[0]->value[1] = 0x00;
> -               drff->report->field[0]->value[2] = weak;
> -               drff->report->field[0]->value[4] = strong;
> -               hid_hw_request(hid, drff->report, HID_REQ_SET_REPORT);
> -
> -               drff->report->field[0]->value[0] = 0xfa;
> -               drff->report->field[0]->value[1] = 0xfe;
> -       } else {
> +       switch (command->cmd) {
> +       case MLNX_START_RUMBLE:
> +               if (strong || weak) {
> +                       strong = strong * 0xff / 0xffff;
> +                       weak = weak * 0xff / 0xffff;
> +
> +                       /* While reverse engineering this device, I
> found that when
> +                       this value is set, it causes the strong rumble
> to function
> +                       at a near maximum speed, so we'll bypass it.
> */
> +                       if (weak == 0x0a)
> +                               weak = 0x0b;
> +
> +                       drff->report->field[0]->value[0] = 0x51;
> +                       drff->report->field[0]->value[1] = 0x00;
> +                       drff->report->field[0]->value[2] = weak;
> +                       drff->report->field[0]->value[4] = strong;

This looks like an endianness bug.

> +                       hid_hw_request(hid, drff->report,
> HID_REQ_SET_REPORT);

	Regards
		Oliver


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