[IMPORTANT] Document that input_device is utilized by the android, and sdl2 controller drivers

[davidhedlund]

Description

The input_device is utilized by the udev and linuxraw controller drivers, while input_vendor_id and input_product_id are not used by these drivers. Conversely, the input_vendor_id and input_product_id are used by the Android and SDL2 controller drivers, where input_device is not utilized. This discrepancy is highlighted in the related issue #16904.

Expected behavior

The "Save Controller Profile" feature should not add input_device to the autoconfig file when using Android or SDL2 drivers.

Actual behavior

Currently, "Save Controller Profile" adds input_device to the autoconfig file, which is unnecessary for Android and SDL2 drivers.

Steps to reproduce the bug

1. Navigate to: Settings -> Drivers -> Controller.
2. Change the controller driver to "android" or "sdl2".
3. Restart RetroArch to apply the setting.
4. Navigate to: Settings -> Input -> RetroPad Binds -> Port 1 Controls.
5. Click on "Save Controller Profile".
6. Close RetroArch.

Example of a Sony DualSense generated file called "PS5 Controller.cfg":

input_driver = "sdl2"
input_device = "PS5 Controller"
input_vendor_id = "1356"
input_product_id = "3302"

7. Open RetroArch. It will pop-up: "PS5 Controller configured on port 1"
8. Close RetoArch
9. Rename "PS5 Controller.cfg" to "test.cfg" and delete "input_device" from it

input_driver = "sdl2"
input_vendor_id = "1356"
input_product_id = "3302"

10. Open RetroArch again. It still displays: "PS5 Controller configured on port 1", indicating that input_device is redundant.

Version/Commit

• RetroArch: 1.19.1 flatpak

[zoltanvb]

SDL joypad driver seems to handle name along with vendor / product IDs:

RetroArch/input/drivers_joypad/sdl_joypad.c

Line 155 in 329b16d

input_autoconfigure_connect(

Android also fills the name, it even has some extra processing for that field:

RetroArch/input/drivers/android_input.c

Line 1330 in 329b16d

input_autoconfigure_connect(

These drivers are operating the same way as udev in #16904, adding all possible identification info for the structure, so it seems to be correct.

[davidhedlund]

• Documented: Update controller-autoconfiguration.md -- The android, udev, and sdl2 drivers can use either the Device Index (input_device) or a combination of Vendor ID (input_vendor_id) and Product ID (input_product_id) -- Thanks zoltanvb! docs#984

Thank you very much for taking the time to assist Zoltanvb!