Address wake from sleep instability

docs/config_options.md

@@ -97,6 +97,8 @@ This is a C header file that is one of the first things included, and will persi
   * sets the maximum power (in mA) over USB for the device (default: 500)
 * `#define USB_POLLING_INTERVAL_MS 10`
   * sets the USB polling rate in milliseconds for the keyboard, mouse, and shared (NKRO/media keys) interfaces
+* `#define USB_SUSPEND_WAKEUP_DELAY 200`
+  * set the number of milliseconde to pause after sending a wakeup packet
 * `#define F_SCL 100000L`
   * sets the I2C clock rate speed for keyboards using I2C. The default is `400000L`, except for keyboards using `split_common`, where the default is `100000L`.
 

tmk_core/common/avr/suspend.c

@@ -102,7 +102,6 @@ static void power_down(uint8_t wdto) {
 #    if defined(RGBLIGHT_SLEEP) && defined(RGBLIGHT_ENABLE)
     rgblight_suspend();
 #    endif
-    suspend_power_down_kb();
 
     // TODO: more power saving
     // See PicoPower application note

tmk_core/common/suspend.h

@@ -12,3 +12,7 @@ void suspend_wakeup_init_user(void);
 void suspend_wakeup_init_kb(void);
 void suspend_power_down_user(void);
 void suspend_power_down_kb(void);
+
+#ifndef USB_SUSPEND_WAKEUP_DELAY
+#    define USB_SUSPEND_WAKEUP_DELAY 200
+#endif

tmk_core/protocol/chibios/usb_main.c

@@ -708,6 +708,17 @@ void init_usb_driver(USBDriver *usbp) {
 void restart_usb_driver(USBDriver *usbp) {
     usbStop(usbp);
     usbDisconnectBus(usbp);
+
+#if USB_SUSPEND_WAKEUP_DELAY > 0
+    // Some hubs, kvm switches, and monitors do
+    // weird things, with USB device state bouncing
+    // around wildly on wakeup, yielding race
+    // conditions that can corrupt the keyboard state.
+    //
+    // Pause for a while to let things settle...
+    wait_ms(USB_SUSPEND_WAKEUP_DELAY);
+#endif
+
     usbStart(usbp, &usbcfg);
     usbConnectBus(usbp);
 }

tmk_core/protocol/lufa/lufa.c

@@ -435,7 +435,9 @@ void EVENT_USB_Device_Suspend() {
  */
 void EVENT_USB_Device_WakeUp() {
     print("[W]");
+#if defined(NO_USB_STARTUP_CHECK)
     suspend_wakeup_init();
+#endif
 
 #ifdef SLEEP_LED_ENABLE
     sleep_led_disable();
@@ -1073,12 +1075,26 @@ int main(void) {
     print("Keyboard start.\n");
     while (1) {
 #if !defined(NO_USB_STARTUP_CHECK)
-        while (USB_DeviceState == DEVICE_STATE_Suspended) {
+        if (USB_DeviceState == DEVICE_STATE_Suspended) {
             print("[s]");
-            suspend_power_down();
-            if (USB_Device_RemoteWakeupEnabled && suspend_wakeup_condition()) {
-                USB_Device_SendRemoteWakeup();
+            while (USB_DeviceState == DEVICE_STATE_Suspended) {
+                suspend_power_down();
+                if (USB_Device_RemoteWakeupEnabled && suspend_wakeup_condition()) {
+                    USB_Device_SendRemoteWakeup();
+                    clear_keyboard();
+
+#    if USB_SUSPEND_WAKEUP_DELAY > 0
+                    // Some hubs, kvm switches, and monitors do
+                    // weird things, with USB device state bouncing
+                    // around wildly on wakeup, yielding race
+                    // conditions that can corrupt the keyboard state.
+                    //
+                    // Pause for a while to let things settle...
+                    wait_ms(USB_SUSPEND_WAKEUP_DELAY);
+#    endif
+                }
             }
+            suspend_wakeup_init();
         }
 #endif