From mboxrd@z Thu Jan  1 00:00:00 1970
From: Johan Hovold <johan@kernel.org>
Subject: Re: [PATCH v3] leds: USB: HID: Add support for MSI GT683R led panels
Date: Wed, 11 Jun 2014 17:30:05 +0200
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To: Janne Kanniainen <janne.kanniainen@gmail.com>
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On Wed, Jun 11, 2014 at 04:05:42PM +0200, Johan Hovold wrote:
> On Wed, Jun 11, 2014 at 12:21:39AM +0300, Janne Kanniainen wrote:

> > +static const char gt683r_led_select_leds[GT683R_BUFFER_SIZE] = { 0x01, 0x02, 0x30, 0x00,
> > +								 0x00, 0x00, 0x00, 0x00 };
> > +static const char gt683r_led_select_type[GT683R_BUFFER_SIZE] = { 0x01, 0x02, 0x20, 0x00,
> > +								 0x01, 0x00, 0x00, 0x00 };
> 
> 80 char limit.
> 
> Perhaps move these to gt683r_led_set, which is the only place where they
> are used?

Or, as I hinted earlier, just allocate the 8-byte buffer using kzalloc
and only initialise the non-zero bytes directly. The first byte should
be the report id (0x01). I noticed that some hid-drivers use this fact
when sending the raw request (see below).

> > +
> > +static void gt683r_brightness_set(struct led_classdev *led_cdev,
> > +				  enum led_brightness brightness)
> > +{
> > +	struct gt683r_led *led =
> > +			container_of(led_cdev, struct gt683r_led, led_dev);
> > +
> > +	led->brightness = brightness;
> > +
> > +	schedule_work(&led->work);
> > +}
> > +
> > +static int gt683r_led_snd_msg(struct gt683r_led *led, char *msg)
> > +{
> > +	int ret;
> > +
> > +	ret = hid_hw_raw_request(led->hdev, 0x01, msg, GT683R_BUFFER_SIZE,
> > +				HID_FEATURE_REPORT, HID_REQ_SET_REPORT);

That is, you could use msg[0] here instead of 0x01.

> > +	if (ret < 0) {
> > +		hid_err(led->hdev,
> > +			"failed to send set report request: %i\n", ret);
> > +		return ret;
> > +	}
> > +
> > +	return 0;
> > +}

Johan