[202012] Update MMU and ECN settings for Arista-7260CX3-D96C16 (sonic-net#11427)

Signed-off-by: Neetha John <[email protected]>

Why I did it
Missed this sku in the previous PR sonic-net#11398

How I did it
Update the dynamic threshold to 0 and ECN settings as 2mb/10mb/5%

How to verify it
Updated unit tests to use the modified values for 7260 ecn settings.

Author: neethajohn

device/arista/x86_64-arista_7260cx3_64/Arista-7260CX3-D96C16/pg_profile_lookup.ini

@@ -1,8 +1,8 @@
 # PG lossless profiles.
 # speed cable size    xon  xoff     threshold xon_offset
-  50000  5m   1248    1248 56160    -3        2496
- 100000  5m   1248    1248 96928    -3        2496
-  50000  40m  1248    1248 96096    -3        2496
- 100000  40m  1248    1248 177632   -3        2496
-  50000  300m 1248    1248 141856   -3        2496
- 100000  300m 1248    1248 268736   -3        2496
+  50000  5m   1248    1248 56160    0         2496
+ 100000  5m   1248    1248 96928    0         2496
+  50000  40m  1248    1248 96096    0         2496
+ 100000  40m  1248    1248 177632   0         2496
+  50000  300m 1248    1248 141856   0         2496
+ 100000  300m 1248    1248 268736   0         2496

device/arista/x86_64-arista_7260cx3_64/Arista-7260CX3-D96C16/qos.json.j2

@@ -1 +1,21 @@
+{%- macro generate_wred_profiles() %}
+    "WRED_PROFILE": {
+        "AZURE_LOSSLESS" : {
+            "wred_green_enable"      : "true",
+            "wred_yellow_enable"     : "true",
+            "wred_red_enable"        : "true",
+            "ecn"                    : "ecn_all",
+            "green_max_threshold"    : "10000000",
+            "green_min_threshold"    : "2000000",
+            "yellow_max_threshold"   : "2097152",
+            "yellow_min_threshold"   : "1048576",
+            "red_max_threshold"      : "2097152",
+            "red_min_threshold"      : "1048576",
+            "green_drop_probability" : "5",
+            "yellow_drop_probability": "5",
+            "red_drop_probability"   : "5"
+        }
+    },
+{%- endmacro %}
+
 {%- include 'qos_config.j2' %}

src/sonic-config-engine/tests/sample_output/py2/qos-arista7260.json

@@ -0,0 +1 @@
+../py3/qos-arista7260-t1-remap-disabled.json

src/sonic-config-engine/tests/sample_output/py3/qos-arista7260.json

@@ -0,0 +1 @@
+qos-arista7260-t1-remap-disabled.json

src/sonic-config-engine/tests/test_j2files.py

@@ -238,6 +238,9 @@ def test_qos_dell9332_render_template(self):
     def test_qos_dell6100_render_template(self):
         self._test_qos_render_template('dell', 'x86_64-dell_s6100_c2538-r0', 'Force10-S6100', 'sample-dell-6100-t0-minigraph.xml', 'qos-dell6100.json')
 
+    def test_qos_arista7260_render_template(self):
+        self._test_qos_render_template('arista', 'x86_64-arista_7260cx3_64', 'Arista-7260CX3-D96C16', 'sample-arista-7260-t1-minigraph-remap-disabled.xml', 'qos-arista7260.json')
+
     def _test_qos_render_template(self, vendor, platform, sku, minigraph, expected):
         file_exist, dir_exist = self.create_machine_conf(platform, vendor)
         dir_path = os.path.join(self.test_dir, '..', '..', '..', 'device', vendor, platform, sku)