Address wake from sleep instability (#11450)

* resolve race condition between suspend and wake in LUFA

* avoid multiple calls to suspend_power_down() / suspend_wakeup_init()

* Remove duplicate suspend_power_down_kb() call

* pause on wakeup to wait for USB state to settle

* need the repeated suspend_power_down() (that's where the sleep is)

* more efficient implementation

* fine tune the pause after sending wakeup

* speculative chibios version of pause-after-wake

* make wakeup delay configurable, and adjust value

* better location for wakeup delay

tmk_core/common/avr/suspend.c

@@ -110,7 +110,6 @@ static void power_down(uint8_t wdto) {
         rgblight_disable_noeeprom();
     }
 #    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

@@ -701,6 +701,17 @@ 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

@@ -498,7 +498,9 @@ 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();
@@ -1184,13 +1186,27 @@ 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]");
+            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
 
         keyboard_task();