From 9a4618b05b9f1093908c2153c719c5eb5d4a79ee Mon Sep 17 00:00:00 2001
From: Joshua Diamond <josh@windowoffire.com>
Date: Mon, 1 Feb 2021 19:12:41 -0500
Subject: [PATCH] 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
---
docs/config_options.md | 2 ++
tmk_core/common/avr/suspend.c | 1 -
tmk_core/common/suspend.h | 4 ++++
tmk_core/protocol/chibios/usb_main.c | 11 +++++++++++
tmk_core/protocol/lufa/lufa.c | 24 ++++++++++++++++++++----
5 files changed, 37 insertions(+), 5 deletions(-)
diff --git a/docs/config_options.md b/docs/config_options.md
index a3262b418b..9a64b9b3d2 100644
--- a/docs/config_options.md
+++ b/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`.
diff --git a/tmk_core/common/avr/suspend.c b/tmk_core/common/avr/suspend.c
index 9db0e0064a..b784a0835d 100644
--- a/tmk_core/common/avr/suspend.c
+++ b/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
diff --git a/tmk_core/common/suspend.h b/tmk_core/common/suspend.h
index 766df95aa1..9d17d984ed 100644
--- a/tmk_core/common/suspend.h
+++ b/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
diff --git a/tmk_core/protocol/chibios/usb_main.c b/tmk_core/protocol/chibios/usb_main.c
index cb7aeb23b2..13b1e34d28 100644
--- a/tmk_core/protocol/chibios/usb_main.c
+++ b/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);
}
diff --git a/tmk_core/protocol/lufa/lufa.c b/tmk_core/protocol/lufa/lufa.c
index 623aa33ff5..74e48222d0 100644
--- a/tmk_core/protocol/lufa/lufa.c
+++ b/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