From 13a9a75f79a97569d00a00b3ee395afabe7e5f9e Mon Sep 17 00:00:00 2001
From: "andrey.bychkov" <andrey@signalmodelling.ru>
Date: Wed, 5 Aug 2026 17:38:22 +0300
Subject: [PATCH] fix(PISerial): break infinite loop when readDevice returns <=
 0

In the blocking read path (timeout_ms <= 0), the while loop had no
exit condition for readDevice() returning 0 (EOF) or -1 (error).
This caused an infinite busy-loop at 100% CPU. Added 'else break'
to exit the loop on read failure, matching the timeout branch
which already handles this case.
---
 libs/main/io_devices/piserial.cpp | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/libs/main/io_devices/piserial.cpp b/libs/main/io_devices/piserial.cpp
index 9859ef68..401d5dfc 100644
--- a/libs/main/io_devices/piserial.cpp
+++ b/libs/main/io_devices/piserial.cpp
@@ -513,7 +513,10 @@ bool PISerial::read(void * data, int size, double timeout_ms) {
 		all     = readDevice(data, 1);
 		while (all < size) {
 			ret = readDevice(&((uchar *)data)[all], size - all);
-			if (ret > 0) all += ret;
+			if (ret > 0)
+				all += ret;
+			else
+				break;
 		}
 		setOption(BlockingRead, br);
 		received(data, all);
@@ -1235,8 +1238,8 @@ PIVector<PISerial::DeviceInfo> PISerial::availableDevicesInfo(bool test) {
 	for (const auto & e: de) { // TODO changes in FileInfo
 		for (const auto & p: prefixes) {
 			if (e.name().startsWith(p)) {
-				di      = DeviceInfo();
-				di.path = e.path;
+				di          = DeviceInfo();
+				di.path     = e.path;
 #	ifdef LINUX
 				ssize_t lsz = readlink(("/sys/class/tty/" + e.name()).dataAscii(), linkbuf, 1024);
 				if (lsz > 0) {