diff --git a/drivers/hid/hid-nintendo.c b/drivers/hid/hid-nintendo.c index 5bfc0c4504608..2b781cc9082b4 100644 --- a/drivers/hid/hid-nintendo.c +++ b/drivers/hid/hid-nintendo.c @@ -1527,6 +1527,7 @@ static int joycon_set_rumble(struct joycon_ctlr *ctlr, u16 amp_r, u16 amp_l, u16 freq_l_low; u16 freq_l_high; unsigned long flags; + int next_rq_head; spin_lock_irqsave(&ctlr->lock, flags); freq_r_low = ctlr->rumble_rl_freq; @@ -1547,8 +1548,21 @@ static int joycon_set_rumble(struct joycon_ctlr *ctlr, u16 amp_r, u16 amp_l, joycon_encode_rumble(data, freq_l_low, freq_l_high, amp); spin_lock_irqsave(&ctlr->lock, flags); - if (++ctlr->rumble_queue_head >= JC_RUMBLE_QUEUE_SIZE) - ctlr->rumble_queue_head = 0; + + next_rq_head = ctlr->rumble_queue_head + 1; + if (next_rq_head >= JC_RUMBLE_QUEUE_SIZE) + next_rq_head = 0; + + /* Did we overrun the circular buffer? + * If so, be sure we keep the latest intended rumble state. + */ + if (next_rq_head == ctlr->rumble_queue_tail) { + hid_dbg(ctlr->hdev, "rumble queue is full"); + /* overwrite the prior value at the end of the circular buf */ + next_rq_head = ctlr->rumble_queue_head; + } + + ctlr->rumble_queue_head = next_rq_head; memcpy(ctlr->rumble_data[ctlr->rumble_queue_head], data, JC_RUMBLE_DATA_SIZE); @@ -2128,7 +2142,7 @@ static int nintendo_hid_probe(struct hid_device *hdev, ctlr->hdev = hdev; ctlr->ctlr_state = JOYCON_CTLR_STATE_INIT; - ctlr->rumble_queue_head = JC_RUMBLE_QUEUE_SIZE - 1; + ctlr->rumble_queue_head = 0; ctlr->rumble_queue_tail = 0; hid_set_drvdata(hdev, ctlr); mutex_init(&ctlr->output_mutex); generated by cgit (git 2.34.1) at 2023-04-10 17:10:33 +0000