[Mellanox] Remove external-changes patch if no downstream changes are found (#18795)

- Why I did it
Bug Fix: when the external-changes.patch is empty, sonic-linux-kernel build fails when called with INCLUDE_EXTERNAL_PATCHES=y flag

How I did it

- How to verify it
Verified by integrating a hw-mgmt version without downstream patches and building linux kernel with EXTERNAL_PATCHES flag

Signed-off-by: Vivek Reddy <[email protected]>

Author: vivekrnv

platform/mellanox/integration-scripts.mk

@@ -163,11 +163,8 @@ endif
 	git add -- $(PLATFORM_PATH)/non-upstream-patches/
 	git add -- $(PLATFORM_PATH)/hw-management.mk
 
-	echo -en '\n###-> Non Upstream external-changes.patch changes <-###\n' >> ${HWMGMT_USER_OUTFILE}
-	git diff --no-color --staged -- $(PLATFORM_PATH)/non-upstream-patches/external-changes.patch >> ${HWMGMT_USER_OUTFILE}
-
-	echo -en '\n###-> Non Upstream kconfig-inclusions.patch changes <-###\n' >> ${HWMGMT_USER_OUTFILE}
-	git diff --no-color --staged -- $(PLATFORM_PATH)/non-upstream-patches/kconfig-inclusions.patch >> ${HWMGMT_USER_OUTFILE}
+	echo -en '\n###-> Non Upstream changes <-###\n' >> ${HWMGMT_USER_OUTFILE}
+	git diff --no-color --staged -- $(PLATFORM_PATH)/non-upstream-patches/ >> ${HWMGMT_USER_OUTFILE}
 
 	echo -en '\n###-> Non Upstream patch list file <-###\n' >> ${HWMGMT_USER_OUTFILE}
 	git diff --no-color --staged -- $($(MLNX_HW_MANAGEMENT)_SRC_PATH)/hwmgmt_nonup_patches >> ${HWMGMT_USER_OUTFILE}

platform/mellanox/integration-scripts/hwmgmt_kernel_patches.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python
 #
-# Copyright (c) 2023 NVIDIA CORPORATION & AFFILIATES.
+# Copyright (c) 2023-2024 NVIDIA CORPORATION & AFFILIATES.
 # Apache-2.0
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -18,7 +18,7 @@
 
 from hwmgmt_helper import *
 
-COMMIT_TITLE = "Intgerate HW-MGMT {} Changes"
+COMMIT_TITLE = "Integrate HW-MGMT {} Changes"
 
 PATCH_TABLE_LOC = "platform/mellanox/hw-management/hw-mgmt/recipes-kernel/linux/"
 PATCHWORK_LOC = "linux-{}/patchwork"
@@ -270,9 +270,15 @@ def rm_old_non_up_mlnx(self):
             sys.exit(1)
 
     def mv_new_non_up_mlnx(self):
+        dest_fpath = os.path.join(self.args.build_root, NON_UP_PATCH_LOC)
+        if not Data.new_non_up and os.path.exists(dest_fpath):
+            os.rmdir(dest_fpath)
+            return
+
         for patch in Data.new_non_up:
             src_path = os.path.join(self.args.non_up_patches, patch)
-            shutil.copy(src_path, os.path.join(self.args.build_root, NON_UP_PATCH_LOC))
+            os.makedirs(dest_fpath, exist_ok=True)
+            shutil.copy(src_path, dest_fpath)
 
     def construct_series_with_non_up(self):
         Data.agg_slk_series = copy.deepcopy(Data.up_slk_series) 
@@ -309,7 +315,23 @@ def get_series_diff(self):
         return lines
 
     def get_merged_diff(self, series_diff: list, kcfg_diff: list) -> list:
-        return series_diff + ["\n"] + kcfg_diff
+        if series_diff or kcfg_diff:
+            return series_diff + ["\n"] + kcfg_diff
+        else:
+            return []
+
+    def write_non_up_diff(self, series_diff, kcfg_diff):
+        final_diff = self.get_merged_diff(series_diff, kcfg_diff)
+        non_up_diff_path = os.path.join(self.args.build_root, NON_UP_DIFF)
+        if "".join(final_diff).strip():
+            # don't write anything if the diff just contains whitespaces
+            FileHandler.write_lines(non_up_diff_path, final_diff, True)
+        else:
+            # if nothing to write, delete the patch file
+            try:
+                os.remove(non_up_diff_path)
+            except OSError as error:
+                print("-> NOTICE File {} remove failed with error {}".format(non_up_diff_path, error))
 
     def list_patches(self):
         old_up_patches = []
@@ -388,8 +410,7 @@ def perform(self):
         series_diff = self.get_series_diff()
         # handle kconfig and get any diff
         kcfg_diff = self.kcfg_handler.perform()
-        final_diff = self.get_merged_diff(series_diff, kcfg_diff)
-        FileHandler.write_lines(os.path.join(self.args.build_root, NON_UP_DIFF), final_diff, True)
+        self.write_non_up_diff(series_diff, kcfg_diff)
 
         path = os.path.join(self.args.build_root, PATCH_TABLE_LOC)
         patch_table = load_patch_table(path, Data.k_ver)

platform/mellanox/integration-scripts/tests/test_hwmgmtaction.py

@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2023 NVIDIA CORPORATION & AFFILIATES.
+# Copyright (c) 2023-2024 NVIDIA CORPORATION & AFFILIATES.
 # Apache-2.0
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -56,7 +56,7 @@
 """
 
 TEST_SLK_COMMIT = """\
-Intgerate HW-MGMT 7.0030.0937 Changes
+Integrate HW-MGMT 7.0030.0937 Changes
  ## Patch List
 * 0002-i2c-mlxcpld-Decrease-polling-time-for-performance-im.patch : https://github.com/torvalds/linux/commit/cb9744178f33
 * 0003-i2c-mlxcpld-Add-support-for-I2C-bus-frequency-settin.patch : https://github.com/torvalds/linux/commit/66b0c2846ba8
@@ -71,7 +71,7 @@
 """
 
 TEST_SB_COMMIT = """\
-Intgerate HW-MGMT 7.0030.0937 Changes
+Integrate HW-MGMT 7.0030.0937 Changes
 
 """
 
@@ -165,8 +165,8 @@ def test_write_final_diff(self, mock_write_lines):
         series_diff = self.action.get_series_diff()
         kcfg_diff = self._get_kcfg_incl_diff()
         final_diff = self.action.get_merged_diff(series_diff, kcfg_diff)
+        self.action.write_non_up_diff(series_diff, kcfg_diff)
         print("".join(final_diff))
-        FileHandler.write_lines(os.path.join(self.action.args.build_root, NON_UP_DIFF), final_diff, True)
         assert check_file_content(MOCK_INPUTS_DIR+"expected_data/external-changes.patch")
 
     def test_commit_msg(self):