From 69c5d959e75b9bf9689be39da0dd8abd6078d89a Mon Sep 17 00:00:00 2001
From: v1ne <v1ne2go@gmail.com>
Date: Fri, 3 Apr 2020 03:51:09 +0200
Subject: [PATCH] rdtech-dps: Make it work in SmuView

Without the mutex, concurrent reception from the ModBus port leads to CRC
errors.
---
 src/hardware/rdtech-dps/api.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/hardware/rdtech-dps/api.c b/src/hardware/rdtech-dps/api.c
index 9a08c792..fad31d62 100644
--- a/src/hardware/rdtech-dps/api.c
+++ b/src/hardware/rdtech-dps/api.c
@@ -305,7 +305,9 @@ static int dev_acquisition_start(const struct sr_dev_inst *sdi)
 	devc = sdi->priv;
 
 	/* Prefill actual states */
+	g_mutex_lock(&devc->rw_mutex);
 	ret = rdtech_dps_read_holding_registers(modbus, REG_PROTECT, 3, registers);
+	g_mutex_unlock(&devc->rw_mutex);
 	if (ret != SR_OK)
 		return ret;
 	devc->actual_ovp_state = RB16(registers + 0) == STATE_OVP;