Re: [PATCH v2 02/13] HID: playstation: use DualSense MAC address as unique identifier.

["Barnabás Pőcze" <pobrn@protonmail.com>]

Hi


2021. január 2., szombat 23:30 keltezéssel, Roderick Colenbrander írta:

> From: Roderick Colenbrander roderick.colenbrander@sony.com
>
> Use the DualSense MAC address as a unique identifier for the HID device.
>
> Signed-off-by: Roderick Colenbrander roderick.colenbrander@sony.com
>
> [...]
>  /* Button masks for DualSense input report. */
>  #define DS_BUTTONS0_HAT_SWITCH	GENMASK(3, 0)
>  #define DS_BUTTONS0_SQUARE	BIT(4)
> @@ -132,6 +136,7 @@  static struct input_dev *ps_allocate_input_dev(struct hid_device *hdev, const ch
>  	return input_dev;
>  }
>
> +

I think this extra empty line is not necessary here.


>  static struct input_dev *ps_gamepad_create(struct hid_device *hdev)
>  {
>  	struct input_dev *gamepad;
> @@ -162,6 +167,34 @@  static struct input_dev *ps_gamepad_create(struct hid_device *hdev)
>  	return gamepad;
>  }
>
> +static int dualsense_get_mac_address(struct dualsense *ds)
> +{
> +	uint8_t *buf;
> +	int ret = 0;
> +
> +	buf = kzalloc(DS_FEATURE_REPORT_PAIRING_INFO_SIZE, GFP_KERNEL);
> +	if (!buf)
> +		return -ENOMEM;
> +
> +	ret = hid_hw_raw_request(ds->base.hdev, DS_FEATURE_REPORT_PAIRING_INFO, buf,
> +			DS_FEATURE_REPORT_PAIRING_INFO_SIZE, HID_FEATURE_REPORT,
> +			HID_REQ_GET_REPORT);
> +	if (ret < 0)
> +		goto err_free;
> +	else if (ret != DS_FEATURE_REPORT_PAIRING_INFO_SIZE) {

As per coding style[1], please either use {} for all branches, or just drop the
`else` and maybe add a new line:

```
if (ret < 0)
  goto ...

if (ret != ...) {
  ...
}
```

> +		hid_err(ds->base.hdev, "failed to retrieve DualSense pairing info\n");

I think this message could be improved to better pinpoint the actual problem
that triggers it.


> +		ret = -EINVAL;
> +		goto err_free;
> +	}
> +
> +	/* Note MAC address is stored in little endian order. */

Maybe this comment would be better placed in `struct ps_device`?


> +	memcpy(ds->base.mac_address, &buf[1], sizeof(ds->base.mac_address));
> +
> +err_free:
> +	kfree(buf);
> +	return ret;
> +}
> [...]


[1]: https://www.kernel.org/doc/html/latest/process/coding-style.html#placing-braces-and-spaces


Regards,
Barnabás Pőcze