diff --git a/trunner/harness/plo.py b/trunner/harness/plo.py
index 107810c6..721db75a 100644
--- a/trunner/harness/plo.py
+++ b/trunner/harness/plo.py
@@ -146,14 +146,24 @@ def erase(self, device: str, offset: int, size: int, timeout: Optional[int] = No
             e.cmd = cmd
             raise e
 
-    def jffs2(self, device: str, erase: bool, cleanmarkers: PloJffs2CleanmarkerSpec, timeout: Optional[int] = None):
+    def jffs2(self, device: str, erase: bool, cleanmarkers: PloJffs2CleanmarkerSpec, block_timeout: int):
         """Performs jffs2 command."""
 
+        block_count = cleanmarkers.number_of_blocks
+
         cmd = f"jffs2 -d {device} -c {cleanmarkers}"
         if erase:
             cmd += " -e"
 
-        self.cmd(cmd, timeout)
+        self.send_cmd(cmd)
+
+        for i in range(0, block_count):
+            try:
+                self.dut.expect_exact(f"jffs2: block {i}/{block_count}", timeout=block_timeout)
+            except pexpect.TIMEOUT as e:
+                raise PloError("Wrong jffs2 command output!", cmd=cmd, output=self.dut.before) from e
+
+        self._assert_prompt()
 
     def app(
         self, device: str, file: str, imap: str, dmap: str, exec: bool = False
@@ -220,7 +230,8 @@ class PloJffsImageProperty(PloImageProperty):
 
     flash_device_id: str
     cleanmarkers_args: PloJffs2CleanmarkerSpec
-    timeout: int
+    # optimal timeout for erasing 1 block using jffs2 command
+    block_timeout: Optional[int] = 1
 
 
 class PloImageLoader(TerminalHarness, PloInterface):
@@ -258,7 +269,7 @@ def __call__(self):
         self.plo_loader()
 
         if isinstance(self.image, PloJffsImageProperty):
-            self.jffs2(self.image.flash_device_id, True, self.image.cleanmarkers_args, self.image.timeout)
+            self.jffs2(self.image.flash_device_id, True, self.image.cleanmarkers_args, self.image.block_timeout)
 
         with self.phoenixd.run():
             self.copy_file2mem(
diff --git a/trunner/target/armv7a7.py b/trunner/target/armv7a7.py
index 31992a7b..d1582c79 100644
--- a/trunner/target/armv7a7.py
+++ b/trunner/target/armv7a7.py
@@ -84,7 +84,6 @@ class IMX6ULLEvkTarget(ARMv7A7Target):
             block_size=0x10000,
             cleanmarker_size=0x10,
         ),
-        timeout=275,
     )
     name = "armv7a7-imx6ull-evk"
 
diff --git a/trunner/target/armv7a9.py b/trunner/target/armv7a9.py
index 2e841e49..833f8e91 100644
--- a/trunner/target/armv7a9.py
+++ b/trunner/target/armv7a9.py
@@ -121,7 +121,6 @@ class Zynq7000ZedboardTarget(ARMv7A9Target):
             block_size=0x10000,
             cleanmarker_size=0x10,
         ),
-        timeout=140,
     )
     name = "armv7a9-zynq7000-zedboard"
 
diff --git a/trunner/test_runner.py b/trunner/test_runner.py
index 171b7305..293ae579 100644
--- a/trunner/test_runner.py
+++ b/trunner/test_runner.py
@@ -29,6 +29,7 @@ def resolve_project_path():
 
 class LogWrapper(StringIO):
     """Wrapper for saving all logs into StringIO and also streaming directly to stream"""
+
     def __init__(self, stream: TextIO):
         super().__init__("")
         self.stream = stream
@@ -152,7 +153,8 @@ def flash(self) -> TestResult:
             self.target.flash_dut()
             result.set_stage(TestStage.DONE)
         except (FlashError, HarnessError) as exc:
-            print(bold("ERROR WHILE FLASHING THE DEVICE"))
+            # the newline is needed to avoid printing exception in the same line as plo prompt
+            print(bold("\nERROR WHILE FLASHING THE DEVICE"))
             print(exc)
             result.fail_harness_exception(exc)
 
@@ -185,7 +187,7 @@ def _export_results_csv(self, results: Sequence[TestResult]):
 
         fname = self.ctx.output + ".csv"
 
-        with open(fname, 'w', encoding='utf-8') as out_csv:
+        with open(fname, "w", encoding="utf-8") as out_csv:
             out_csv.write(TestResult.get_csv_header() + "\n")
             for res in results:
                 out_csv.write(res.to_csv() + "\n")
@@ -206,8 +208,8 @@ def _export_results_xml(self, results: Sequence[TestResult]):
             suite = res.to_junit_testsuite(self.ctx.target.name)
             suite.hostname = self.ctx.host.name
             if is_github_actions():
-                suite.add_property('url', get_ci_url())
-                suite.add_property('SHA', os.environ['GITHUB_SHA'])
+                suite.add_property("url", get_ci_url())
+                suite.add_property("SHA", os.environ["GITHUB_SHA"])
 
             xml.add_testsuite(suite)
 
@@ -220,7 +222,7 @@ def _export_results_xml(self, results: Sequence[TestResult]):
                 from lxml import etree
             except ImportError:
                 from xml.etree import ElementTree as etree
-            with open(fname, 'wb') as out_xml:
+            with open(fname, "wb") as out_xml:
                 text = etree.tostring(xml._elem)
                 out_xml.write(text)
 
@@ -321,10 +323,12 @@ def run(self) -> bool:
 
         sums = Counter(res.status for res in results)
 
-        print(f"TESTS: {len(results)} "
-              f"{green('PASSED')}: {sums.get(Status.OK, 0)} "
-              f"{red('FAILED')}: {sums.get(Status.FAIL, 0)} "
-              f"{yellow('SKIPPED')}: {sums.get(Status.SKIP, 0)}")
+        print(
+            f"TESTS: {len(results)} "
+            f"{green('PASSED')}: {sums.get(Status.OK, 0)} "
+            f"{red('FAILED')}: {sums.get(Status.FAIL, 0)} "
+            f"{yellow('SKIPPED')}: {sums.get(Status.SKIP, 0)}"
+        )
 
         self._export_results_csv(results)
         self._export_results_xml(results)