HID: intel-ish-hid: Send clock sync message immediately after reset

The ISH driver performs a clock sync with the firmware once at system
startup and then every 20 seconds. If a firmware reset occurs right
after a clock sync, the driver would wait 20 seconds before performing
another clock sync with the firmware. This is particularly problematic
with the introduction of the "load firmware from host" feature, where
the driver performs a clock sync with the bootloader and then has to
wait 20 seconds before syncing with the main firmware.

This patch clears prev_sync immediately upon receiving an IPC reset,
so that the main firmware and driver will perform a clock sync
immediately after completing the IPC handshake.

Signed-off-by: Zhang Lixu <[email protected]>
Acked-by: Srinivas Pandruvada <[email protected]>
Signed-off-by: Jiri Kosina <[email protected]>

Author: lixuzha

drivers/hid/intel-ish-hid/ipc/ipc.c

@@ -517,6 +517,10 @@ static int ish_fw_reset_handler(struct ishtp_device *dev)
 	/* ISH FW is dead */
 	if (!ish_is_input_ready(dev))
 		return	-EPIPE;
+
+	/* Send clock sync at once after reset */
+	ishtp_dev->prev_sync = 0;
+
 	/*
 	 * Set HOST2ISH.ILUP. Apparently we need this BEFORE sending
 	 * RESET_NOTIFY_ACK - FW will be checking for it
@@ -577,13 +581,12 @@ static void fw_reset_work_fn(struct work_struct *work)
  */
 static void _ish_sync_fw_clock(struct ishtp_device *dev)
 {
-	static unsigned long	prev_sync;
 	struct ipc_time_update_msg time = {};
 
-	if (prev_sync && time_before(jiffies, prev_sync + 20 * HZ))
+	if (dev->prev_sync && time_before(jiffies, dev->prev_sync + 20 * HZ))
 		return;
 
-	prev_sync = jiffies;
+	dev->prev_sync = jiffies;
 	/* The fields of time would be updated while sending message */
 	ipc_send_mng_msg(dev, MNG_SYNC_FW_CLOCK, &time, sizeof(time));
 }

drivers/hid/intel-ish-hid/ishtp/ishtp-dev.h

@@ -253,6 +253,8 @@ struct ishtp_device {
 	unsigned int	ipc_tx_cnt;
 	unsigned long long	ipc_tx_bytes_cnt;
 
+	/* Time of the last clock sync */
+	unsigned long prev_sync;
 	const struct ishtp_hw_ops *ops;
 	size_t	mtu;
 	uint32_t	ishtp_msg_hdr;