2020. december 29., kedd 20:54 keltezéssel, Roderick Colenbrander írta:

On Tue, Dec 29, 2020 at 10:59 AM Barnabás Pőcze [off-list ref] wrote:

quoted

2020. december 28., hétfő 22:26 keltezéssel, Roderick Colenbrander írta:

quoted

[...]

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+/* Create a DualSense/DualShock4 RGB lightbar represented by a multicolor LED. */
+static struct led_classdev_mc *ps_lightbar_create(struct ps_device *ps_dev,
+     int (*brightness_set)(struct led_classdev *, enum led_brightness))
+{
+     struct hid_device *hdev = ps_dev->hdev;
+     struct led_classdev_mc *lightbar_mc_dev;
+     struct mc_subled *mc_led_info;
+     struct led_classdev *led_cdev;
+     int ret;
+
+     lightbar_mc_dev = devm_kzalloc(&hdev->dev, sizeof(*lightbar_mc_dev), GFP_KERNEL);
+     if (!lightbar_mc_dev)
+             return ERR_PTR(-ENOMEM);
+
+     mc_led_info = devm_kzalloc(&hdev->dev, 3*sizeof(*mc_led_info), GFP_KERNEL);
+     if (!mc_led_info)
+             return ERR_PTR(-ENOMEM);
+

Is there any reason why these are dynamically allocated?

No particular reason. I should probably at least not dynamically
allocate 'mc_dev' and pass it in similar to regular LED registration
(previously I had my regular LEDs dynamically allocated). The
mc_led_info I will probably keep dynamic. It feels a bit nasty to have
the caller be aware of these internal details.
[...]

Could you please elaborate what you mean by "It feels a bit nasty to have
the caller be aware of these internal details."? I don't think I fully understand
what you're referring to.

Maybe I misunderstood your original comment. The question was why both
'lightbar_mc_dev' and 'mc_led_info' were dynamically allocated. I
interpreted it as getting rid of some of the dynamic allocation as
some wasn't needed, but not sure what you had in mind. The code now
looks like:

struct dualsense {
...
        /* RGB lightbar */
        struct led_classdev_mc lightbar; (not a pointer anymore)
}

static int ps_lightbar_register(struct ps_device *ps_dev, struct
led_classdev_mc *lightbar_mc_dev,
              int (*brightness_set)(struct led_classdev *, enum led_brightness))
{
          struct hid_device *hdev = ps_dev->hdev;
          struct mc_subled *mc_led_info;
          struct led_classdev *led_cdev;
          int ret;

          mc_led_info = devm_kzalloc(&hdev->dev,
3*sizeof(*mc_led_info), GFP_KERNEL);
          if (!mc_led_info)
                return -ENOMEM;

          mc_led_info[0].color_index = LED_COLOR_ID_RED;
...

In here I kept 'mc_led_info' as dynamically allocated. I didn't think
it made sense to have the caller know about it. What was your original
idea?
[...]

Thanks, I thought you meant something different, but this clears it up. By the way,
my original idea is really the simplest: have a `struct mc_subled[3]` in the dualsense
struct in addition to the multicolor LED, thus no dynamic allocation (apart from
allocating the dualsense struct) is necessary.