From: Carter Nelson <caternuson@gmail.com>
Date: Mon, 4 Oct 2021 17:41:19 +0000 (-0700)
Subject: Merge pull request #501 from fgervais/mcp2221-empty-i2c-payload
X-Git-Tag: 6.14.0~1
X-Git-Url: https://git.ayoreis.com/Adafruit_Blinka-hackapet.git/commitdiff_plain/64f9d7f1205ce7a20940d8d19b554708c5392780?hp=162d7d578159d2b933d4839a6d982b0153008132

Merge pull request #501 from fgervais/mcp2221-empty-i2c-payload

mcp2221: allow empty i2c payload
---

diff --git a/src/adafruit_blinka/microcontroller/mcp2221/mcp2221.py b/src/adafruit_blinka/microcontroller/mcp2221/mcp2221.py
index 30f45f6..fb9edf3 100644
--- a/src/adafruit_blinka/microcontroller/mcp2221/mcp2221.py
+++ b/src/adafruit_blinka/microcontroller/mcp2221/mcp2221.py
@@ -189,7 +189,7 @@ class MCP2221:
             # bus release will need "a few hundred microseconds"
             time.sleep(0.001)
 
-    # pylint: disable=too-many-arguments
+    # pylint: disable=too-many-arguments,too-many-branches
     def _i2c_write(self, cmd, address, buffer, start=0, end=None):
         if self._i2c_state() != 0x00:
             self._i2c_cancel()
@@ -198,7 +198,7 @@ class MCP2221:
         length = end - start
         retries = 0
 
-        while (end - start) > 0:
+        while (end - start) > 0 or not buffer:
             chunk = min(end - start, MCP2221_MAX_I2C_DATA_LEN)
             # write out current chunk
             resp = self._hid_xfer(
@@ -223,6 +223,8 @@ class MCP2221:
             # yay chunk sent!
             while self._i2c_state() == RESP_I2C_PARTIALDATA:
                 time.sleep(0.001)
+            if not buffer:
+                break
             start += chunk
             retries = 0