From 8cf53c5965eea67cd69ab671cc64e9c6ab92e8f9 Mon Sep 17 00:00:00 2001 From: "Daniel J. Ogorchock" Date: Sat, 11 Sep 2021 13:36:30 -0400 Subject: [PATCH] HID: nintendo: send subcommands after receiving input report Waiting to send subcommands until right after receiving an input report drastically improves subcommand reliability. If the driver has finished initial controller configuration, it now waits until receiving an input report for all subcommands. Signed-off-by: Daniel J. Ogorchock Signed-off-by: Jiri Kosina --- drivers/hid/hid-nintendo.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) diff --git a/drivers/hid/hid-nintendo.c b/drivers/hid/hid-nintendo.c index a95943c2fc6c0..a000a287206e8 100644 --- a/drivers/hid/hid-nintendo.c +++ b/drivers/hid/hid-nintendo.c @@ -335,6 +335,7 @@ struct joycon_ctlr { bool received_resp; u8 usb_ack_match; u8 subcmd_ack_match; + bool received_input_report; /* factory calibration data */ struct joycon_stick_cal left_stick_cal_x; @@ -388,6 +389,26 @@ static int joycon_hid_send_sync(struct joycon_ctlr *ctlr, u8 *data, size_t len, * doing one retry after a timeout appears to always work. */ while (tries--) { + /* + * If we are in the proper reporting mode, wait for an input + * report prior to sending the subcommand. This improves + * reliability considerably. + */ + if (ctlr->ctlr_state == JOYCON_CTLR_STATE_READ) { + unsigned long flags; + + spin_lock_irqsave(&ctlr->lock, flags); + ctlr->received_input_report = false; + spin_unlock_irqrestore(&ctlr->lock, flags); + ret = wait_event_timeout(ctlr->wait, + ctlr->received_input_report, + HZ / 4); + /* We will still proceed, even with a timeout here */ + if (!ret) + hid_warn(ctlr->hdev, + "timeout waiting for input report\n"); + } + ret = __joycon_hid_send(ctlr->hdev, data, len); if (ret < 0) { memset(ctlr->input_buf, 0, JC_MAX_RESP_SIZE); @@ -760,6 +781,18 @@ static void joycon_parse_report(struct joycon_ctlr *ctlr, } input_sync(dev); + + /* + * Immediately after receiving a report is the most reliable time to + * send a subcommand to the controller. Wake any subcommand senders + * waiting for a report. + */ + if (unlikely(mutex_is_locked(&ctlr->output_mutex))) { + spin_lock_irqsave(&ctlr->lock, flags); + ctlr->received_input_report = true; + spin_unlock_irqrestore(&ctlr->lock, flags); + wake_up(&ctlr->wait); + } } static void joycon_rumble_worker(struct work_struct *work) -- 2.39.5