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authorAidan MacDonald <amachronic@protonmail.com>2022-05-26 10:25:50 +0100
committerAidan MacDonald <amachronic@protonmail.com>2022-09-25 06:49:11 -0400
commite75a3fb8c7ea947b54bde5567eb17c54124bb5b6 (patch)
tree055001c859cf6349eeecb2894809c275da0d4737
parente4aec7d648de2553653b378518b5e90f29aeeac3 (diff)
downloadrockbox-e75a3fb8c7.tar.gz
rockbox-e75a3fb8c7.zip
usb: add debounce interval for USB status by event
This makes status by event debounce status changes over a 200ms period, which is what polling was already using. This is helpful on targets where events are excessively noisy and generate a lot of transitions during insertion and extraction. Change-Id: I0eae2cca93aaa865e33c94a1318c27e91c7f7c4b
-rw-r--r--firmware/usb.c44
1 files changed, 35 insertions, 9 deletions
diff --git a/firmware/usb.c b/firmware/usb.c
index c4d07c5533..32f4902c7c 100644
--- a/firmware/usb.c
+++ b/firmware/usb.c
@@ -65,6 +65,9 @@
#define USB_FULL_INIT
#endif
+/* USB detect debouncing interval (200ms taken from the usb polling code) */
+#define USB_DEBOUNCE_TIME (200*HZ/1000)
+
bool do_screendump_instead_of_usb = false;
#if !defined(SIMULATOR) && !defined(USB_NONE)
@@ -580,8 +583,33 @@ void usb_charger_update(void)
#endif
#ifdef USB_STATUS_BY_EVENT
+static int usb_status_tmo_callback(struct timeout* tmo)
+{
+ if(usb_monitor_enabled)
+ {
+ int current_status = usb_detect();
+ int* last_status = (int*)tmo->data;
+
+ if(current_status != *last_status)
+ {
+ /* Signal changed during the timeout; wait longer */
+ *last_status = current_status;
+ return USB_DEBOUNCE_TIME;
+ }
+
+ /* Signal is stable, post the event. The thread will deal with
+ * any spurious transitions (like inserted -> inserted). */
+ queue_post(&usb_queue, current_status, 0);
+ }
+
+ return 0;
+}
+
void usb_status_event(int current_status)
{
+ static struct timeout tmo;
+ static int last_status = USB_EXTRACTED;
+
/* Caller isn't expected to filter for changes in status.
* current_status:
* USB_INSERTED, USB_EXTRACTED
@@ -589,8 +617,9 @@ void usb_status_event(int current_status)
if(usb_monitor_enabled)
{
int oldstatus = disable_irq_save(); /* Dual-use function */
- queue_remove_from_head(&usb_queue, current_status);
- queue_post(&usb_queue, current_status, 0);
+ last_status = current_status;
+ timeout_register(&tmo, usb_status_tmo_callback, USB_DEBOUNCE_TIME,
+ (intptr_t)&last_status);
restore_irq(oldstatus);
}
}
@@ -626,7 +655,6 @@ void usb_firewire_connect_event(void)
static void usb_tick(void)
{
- #define NUM_POLL_READINGS (HZ/5)
static int usb_countdown = -1;
static int last_usb_status = USB_EXTRACTED;
#ifdef USB_FIREWIRE_HANDLING
@@ -641,7 +669,7 @@ static void usb_tick(void)
if(current_firewire_status != last_firewire_status)
{
last_firewire_status = current_firewire_status;
- firewire_countdown = NUM_POLL_READINGS;
+ firewire_countdown = USB_DEBOUNCE_TIME;
}
else
{
@@ -649,8 +677,7 @@ static void usb_tick(void)
if(firewire_countdown >= 0)
firewire_countdown--;
- /* Report to the thread if we have had 3 identical status
- readings in a row */
+ /* Report status when the signal has been stable long enough */
if(firewire_countdown == 0)
{
queue_post(&usb_queue, USB_REQUEST_REBOOT, 0);
@@ -664,7 +691,7 @@ static void usb_tick(void)
if(current_status != last_usb_status)
{
last_usb_status = current_status;
- usb_countdown = NUM_POLL_READINGS;
+ usb_countdown = USB_DEBOUNCE_TIME;
}
else
{
@@ -672,8 +699,7 @@ static void usb_tick(void)
if(usb_countdown >= 0)
usb_countdown--;
- /* Report to the thread if we have had 3 identical status
- readings in a row */
+ /* Report status when the signal has been stable long enough */
if(usb_countdown == 0)
{
queue_post(&usb_queue, current_status, 0);