test/py: dfu: allow boardenv to specify test sizes

Allow the env__dfu_configs boardenv data to specify the set of DFU
transfer sizes to test. Manually specifying test sizes is useful if you
wish to test multiple DFU configurations (e.g. SD card ext4 filesystem, SD
card whole raw partition, RAM, etc.), but don't want to test every
single transfer size on each, to avoid bloating the overall time taken by
testing. If the boardenv doesn't specify a set of sizes, the built-in list
is used as a default, preserving backwards-compatibility.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>

test/py/tests/test_dfu.py

@@ -36,6 +36,14 @@ env__dfu_configs = (
         "fixture_id": "emmc",
         "alt_info": "/dfu_test.bin ext4 0 1;/dfu_dummy.bin ext4 0 1",
         "cmd_params": "mmc 0",
+        # This value is optional.
+        # If present, it specified the set of transfer sizes tested.
+        # If missing, a default list of sizes will be used, which covers
+        #   various useful corner cases.
+        # Manually specifying test sizes is useful if you wish to test 4 DFU
+        # configurations, but don't want to test every single transfer size
+        # on each, to avoid bloating the overall time taken by testing.
+        "test_sizes": (63, 64, 65),
     },
 )
 
@@ -52,7 +60,7 @@ device.)
 # The set of file sizes to test. These values trigger various edge-cases such
 # as one less than, equal to, and one greater than typical USB max packet
 # sizes, and similar boundary conditions.
-test_sizes = (
+test_sizes_default = (
     64 - 1,
     64,
     64 + 1,
@@ -245,7 +253,7 @@ def test_dfu(u_boot_console, env__usb_dev_port, env__dfu_config):
     if not first_usb_dev_port:
         first_usb_dev_port = env__usb_dev_port
     if env__usb_dev_port == first_usb_dev_port:
-        sizes = test_sizes
+        sizes = env__dfu_config.get('test_sizes', test_sizes_default)
     else:
         sizes = []