It's been discovered that BT controller disconnect events correlate to
erratic input report timestamp deltas.
In experimentation, it's been found that ensuring that multiple
timestamp deltas are consistent prior to transmitting a rumble packet
drastically reduces the occurence rate of BT disconnects.
Alter the joycon_enforce_subcmd_rate() function to use this new
approach.
Signed-off-by: Daniel J. Ogorchock <djogorchock@xxxxxxxxx>
---
drivers/hid/hid-nintendo.c | 75 +++++++++++++++++++++++++++++++++++---
1 file changed, 69 insertions(+), 6 deletions(-)
diff --git a/drivers/hid/hid-nintendo.c b/drivers/hid/hid-nintendo.c
index 2b781cc9082b4..250f5d2f888ab 100644
--- a/drivers/hid/hid-nintendo.c
+++ b/drivers/hid/hid-nintendo.c
@@ -433,7 +433,9 @@ struct joycon_ctlr {
u8 usb_ack_match;
u8 subcmd_ack_match;
bool received_input_report;
+ unsigned int last_input_report_msecs;
unsigned int last_subcmd_sent_msecs;
+ unsigned int consecutive_valid_report_deltas;
/* factory calibration data */
struct joycon_stick_cal left_stick_cal_x;
@@ -543,19 +545,54 @@ static void joycon_wait_for_input_report(struct joycon_ctlr *ctlr)
* Sending subcommands and/or rumble data at too high a rate can cause bluetooth
* controller disconnections.
*/
+#define JC_INPUT_REPORT_MIN_DELTA 8
+#define JC_INPUT_REPORT_MAX_DELTA 17
+#define JC_SUBCMD_TX_OFFSET_MS 4
+#define JC_SUBCMD_VALID_DELTA_REQ 3
+#define JC_SUBCMD_RATE_MAX_ATTEMPTS 500
+#define JC_SUBCMD_RATE_LIMITER_USB_MS 20
+#define JC_SUBCMD_RATE_LIMITER_BT_MS 60
+#define JC_SUBCMD_RATE_LIMITER_MS(ctlr) ((ctlr)->hdev->bus == BUS_USB ? JC_SUBCMD_RATE_LIMITER_USB_MS : JC_SUBCMD_RATE_LIMITER_BT_MS)
static void joycon_enforce_subcmd_rate(struct joycon_ctlr *ctlr)
{
- static const unsigned int max_subcmd_rate_ms = 25;
- unsigned int current_ms = jiffies_to_msecs(jiffies);
- unsigned int delta_ms = current_ms - ctlr->last_subcmd_sent_msecs;
+ unsigned int current_ms;
+ unsigned long subcmd_delta;
+ int consecutive_valid_deltas = 0;
+ int attempts = 0;
+ unsigned long flags;
+
+ if (unlikely(ctlr->ctlr_state != JOYCON_CTLR_STATE_READ))
+ return;
- while (delta_ms < max_subcmd_rate_ms &&
- ctlr->ctlr_state == JOYCON_CTLR_STATE_READ) {
+ do {
joycon_wait_for_input_report(ctlr);
current_ms = jiffies_to_msecs(jiffies);
- delta_ms = current_ms - ctlr->last_subcmd_sent_msecs;
+ subcmd_delta = current_ms - ctlr->last_subcmd_sent_msecs;
+
+ spin_lock_irqsave(&ctlr->lock, flags);
+ consecutive_valid_deltas = ctlr->consecutive_valid_report_deltas;
+ spin_unlock_irqrestore(&ctlr->lock, flags);
+
+ attempts++;
+ } while ((consecutive_valid_deltas < JC_SUBCMD_VALID_DELTA_REQ ||
+ subcmd_delta < JC_SUBCMD_RATE_LIMITER_MS(ctlr)) &&
+ ctlr->ctlr_state == JOYCON_CTLR_STATE_READ &&
+ attempts < JC_SUBCMD_RATE_MAX_ATTEMPTS);
+
+ if (attempts >= JC_SUBCMD_RATE_MAX_ATTEMPTS) {
+ hid_warn(ctlr->hdev, "%s: exceeded max attempts", __func__);
+ return;
}
+
ctlr->last_subcmd_sent_msecs = current_ms;
+
+ /*
+ * Wait a short time after receiving an input report before
+ * transmitting. This should reduce odds of a TX coinciding with an RX.
+ * Minimizing concurrent BT traffic with the controller seems to lower
+ * the rate of disconnections.
+ */
+ msleep(JC_SUBCMD_TX_OFFSET_MS);
}
static int joycon_hid_send_sync(struct joycon_ctlr *ctlr, u8 *data, size_t len,
@@ -1223,6 +1260,7 @@ static void joycon_parse_report(struct joycon_ctlr *ctlr,
u8 tmp;
u32 btns;
unsigned long msecs = jiffies_to_msecs(jiffies);
+ unsigned long report_delta_ms = msecs - ctlr->last_input_report_msecs;
spin_lock_irqsave(&ctlr->lock, flags);
if (IS_ENABLED(CONFIG_NINTENDO_FF) && rep->vibrator_report &&
@@ -1364,6 +1402,31 @@ static void joycon_parse_report(struct joycon_ctlr *ctlr,
input_sync(dev);
+ spin_lock_irqsave(&ctlr->lock, flags);
+ ctlr->last_input_report_msecs = msecs;
+ /*
+ * Was this input report a reasonable time delta compared to the prior
+ * report? We use this information to decide when a safe time is to send
+ * rumble packets or subcommand packets.
+ */
+ if (report_delta_ms >= JC_INPUT_REPORT_MIN_DELTA &&
+ report_delta_ms <= JC_INPUT_REPORT_MAX_DELTA) {
+ if (ctlr->consecutive_valid_report_deltas < JC_SUBCMD_VALID_DELTA_REQ)
+ ctlr->consecutive_valid_report_deltas++;
+ } else {
+ ctlr->consecutive_valid_report_deltas = 0;
+ }
+ /*
+ * Our consecutive valid report tracking is only relevant for
+ * bluetooth-connected controllers. For USB devices, we're beholden to
+ * USB's underlying polling rate anyway. Always set to the consecutive
+ * delta requirement.
+ */
+ if (ctlr->hdev->bus == BUS_USB)
+ ctlr->consecutive_valid_report_deltas = JC_SUBCMD_VALID_DELTA_REQ;
+
+ spin_unlock_irqrestore(&ctlr->lock, flags);
+
/*
* Immediately after receiving a report is the most reliable time to
* send a subcommand to the controller. Wake any subcommand senders
--
2.39.1
