HID: intel-ish-hid: move doorbell writing before flush

Reading of IPC_REG_ISH_HOST_FWSTS will flush both message register
and doorbell. So move the doorbell write before reading of
IPC_REG_ISH_HOST_FWSTS.
Signed-off-by: Hong Liu <hong.liu@intel.com>
Tested-by: Hongyan Song <hongyan.song@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

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

@@ -314,6 +314,8 @@ static int write_ipc_from_queue(struct ishtp_device *dev)
 		memcpy(&reg, &r_buf[length >> 2], rem);
 		ish_reg_write(dev, reg_addr, reg);
 	}
+	ish_reg_write(dev, IPC_REG_HOST2ISH_DRBL, doorbell_val);
+
 	/* Flush writes to msg registers and doorbell */
 	ish_reg_read(dev, IPC_REG_ISH_HOST_FWSTS);
 
@@ -321,8 +323,6 @@ static int write_ipc_from_queue(struct ishtp_device *dev)
 	++dev->ipc_tx_cnt;
 	dev->ipc_tx_bytes_cnt += IPC_HEADER_GET_LENGTH(doorbell_val);
 
-	ish_reg_write(dev, IPC_REG_HOST2ISH_DRBL, doorbell_val);
-
 	ipc_send_compl = ipc_link->ipc_send_compl;
 	ipc_send_compl_prm = ipc_link->ipc_send_compl_prm;
 	list_del_init(&ipc_link->link);