From 352f773ec466008db9c40665065636484d415297 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Igor=20Mi=C5=A1i=C4=87?= <igy1000mb@gmail.com>
Date: Thu, 23 Feb 2023 09:57:18 +0100
Subject: [PATCH] systemcmds/mtd: fix rwtest - force data to/from the device

Block Device driver uses a buffer so we need to ensure data is written or read to the device and not to the buffer so we can be sure if the device works properly
---
 src/systemcmds/mtd/mtd.cpp | 56 ++++++++++++++++++++++++++++++++------
 1 file changed, 48 insertions(+), 8 deletions(-)

diff --git a/src/systemcmds/mtd/mtd.cpp b/src/systemcmds/mtd/mtd.cpp
index 0ebe4c9573..1864073002 100644
--- a/src/systemcmds/mtd/mtd.cpp
+++ b/src/systemcmds/mtd/mtd.cpp
@@ -250,33 +250,71 @@ int mtd_rwtest(const mtd_instance_s &instance)
 		}
 
 		printf("rwtest %s testing %zd bytes\n", instance.partition_names[i], expected_size);
-		int fd = open(instance.partition_names[i], O_RDWR);
 
-		if (fd == -1) {
-			PX4_ERR("Failed to open partition");
-			return 1;
-		}
+		bool run = true;
+
+		while (run) {
+
+			int fd = open(instance.partition_names[i], O_RDWR);
+
+			if (fd == -1) {
+				PX4_ERR("Failed to open partition");
+				return 1;
+			}
+
+			if (read(fd, v, sizeof(v)) != sizeof(v)) {
+				PX4_ERR("read failed");
+				close(fd);
+				return 1;
+			}
 
-		while (read(fd, v, sizeof(v)) == sizeof(v)) {
 			count += sizeof(v);
 
 			if (lseek(fd, offset, SEEK_SET) != offset) {
 				PX4_ERR("seek failed");
+				close(fd);
 				return 1;
 			}
 
 			if (write(fd, v, sizeof(v)) != sizeof(v)) {
 				PX4_ERR("write failed");
+				close(fd);
+				return 1;
+			}
+
+			//sync and close to discard data from the Block Device buffer
+			if (OK != fsync(fd)) {
+				PX4_ERR("Failed to fsync");
+				close(fd);
+				return 1;
+			}
+
+			if (OK != close(fd)) {
+				PX4_ERR("Failed to close partition");
+				return 1;
+			}
+
+			fd = open(instance.partition_names[i], O_RDONLY);
+
+			if (fd == -1) {
+				PX4_ERR("Failed to open partition");
 				return 1;
 			}
 
 			if (lseek(fd, offset, SEEK_SET) != offset) {
 				PX4_ERR("seek failed");
+				close(fd);
 				return 1;
 			}
 
 			if (read(fd, v2, sizeof(v2)) != sizeof(v2)) {
 				PX4_ERR("read failed");
+				close(fd);
+				return 1;
+			}
+
+			if (OK != close(fd)) {
+				PX4_ERR("Failed to close partition");
 				return 1;
 			}
 
@@ -286,14 +324,16 @@ int mtd_rwtest(const mtd_instance_s &instance)
 			}
 
 			offset += sizeof(v);
+
+			if (count >= expected_size) {
+				run = false;
+			}
 		}
 
 		if (count != expected_size) {
 			PX4_ERR("Failed to read partition - got %zd/%zd bytes", count, expected_size);
 			return 1;
 		}
-
-		close(fd);
 	}
 
 	printf("rwtest OK\n");