From 6f63c1c37faade7f5af02802a4966a3ba1529c20 Mon Sep 17 00:00:00 2001
From: Zack Middleton <zack@cloemail.com>
Date: Wed, 19 Jun 2019 06:43:36 -0700
Subject: [PATCH] Make GameCube controllers only rumble if both USB cables are
 connected The Nintendo USB GameCube Adapter has two USB connectors. Black for
 data and grey for additional power for rumble. The Wii U and other software
 require both cables to use rumble. The rumble is weaker without the second
 USB cable. Other than that I don't know if there is any negative side affects
 from using rumble with only one cable.

---
 src/joystick/hidapi/SDL_hidapi_gamecube.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/joystick/hidapi/SDL_hidapi_gamecube.c b/src/joystick/hidapi/SDL_hidapi_gamecube.c
index 40314f2e2..d5f513233 100644
--- a/src/joystick/hidapi/SDL_hidapi_gamecube.c
+++ b/src/joystick/hidapi/SDL_hidapi_gamecube.c
@@ -37,6 +37,7 @@
 
 typedef struct {
     SDL_JoystickID joysticks[4];
+    Uint8 rumbleAllowed[4];
     Uint8 rumble[5];
     Uint32 rumbleExpiration[4];
     /* Without this variable, hid_write starts to lag a TON */
@@ -99,6 +100,9 @@ HIDAPI_DriverGameCube_InitDriver(SDL_HIDAPI_DriverData *context, Uint16 vendor_i
         /* Go through all 4 slots */
         curSlot = packet + 1;
         for (i = 0; i < 4; i += 1, curSlot += 9) {
+            /* Only allow rumble if the adapter's second USB cable is connected */
+            ctx->rumbleAllowed[i] = (curSlot[0] & 0x04) != 0;
+
             if (curSlot[0] & 0x30) { /* 0x10 - Wired, 0x20 - Wireless */
                 if (ctx->joysticks[i] == -1) {
                     ctx->joysticks[i] = SDL_GetNextJoystickInstanceID();
@@ -168,6 +172,9 @@ HIDAPI_DriverGameCube_UpdateDriver(SDL_HIDAPI_DriverData *context, int *num_joys
         /* Go through all 4 slots */
         curSlot = packet + 1;
         for (i = 0; i < 4; i += 1, curSlot += 9) {
+            /* Only allow rumble if the adapter's second USB cable is connected */
+            ctx->rumbleAllowed[i] = (curSlot[0] & 0x04) != 0;
+
             if (curSlot[0] & 0x30) { /* 0x10 - Wired, 0x20 - Wireless */
                 if (ctx->joysticks[i] == -1) {
                     ctx->joysticks[i] = SDL_GetNextJoystickInstanceID();
@@ -238,7 +245,7 @@ HIDAPI_DriverGameCube_UpdateDriver(SDL_HIDAPI_DriverData *context, int *num_joys
     now = SDL_GetTicks();
     for (i = 0; i < 4; i += 1) {
         if (ctx->rumbleExpiration[i] > 0) {
-            if (SDL_TICKS_PASSED(now, ctx->rumbleExpiration[i])) {
+            if (SDL_TICKS_PASSED(now, ctx->rumbleExpiration[i]) || !ctx->rumbleAllowed[i]) {
                 ctx->rumble[i + 1] = 0;
                 ctx->rumbleExpiration[i] = 0;
                 ctx->rumbleUpdate = 1;
@@ -325,6 +332,9 @@ HIDAPI_DriverGameCube_Rumble(SDL_HIDAPI_DriverData *context, SDL_Joystick *joyst
     Uint8 i, val;
     for (i = 0; i < 4; i += 1) {
         if (instance == ctx->joysticks[i]) {
+            if (!ctx->rumbleAllowed[i]) {
+                return SDL_SetError("Second USB cable for WUP-028 not connected");
+            }
             val = (low_frequency_rumble > 0 || high_frequency_rumble > 0);
             if (val != ctx->rumble[i + 1]) {
                 ctx->rumble[i + 1] = val;
@@ -338,7 +348,7 @@ HIDAPI_DriverGameCube_Rumble(SDL_HIDAPI_DriverData *context, SDL_Joystick *joyst
             return 0;
         }
     }
-    return -1;
+    return -1; /* Should never get here! */
 }
 
 SDL_HIDAPI_DeviceDriver SDL_HIDAPI_DriverGameCube =