--- zzzz-none-000/linux-3.10.107/Documentation/devicetree/bindings/i2c/i2c-arb-gpio-challenge.txt	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/Documentation/devicetree/bindings/i2c/i2c-arb-gpio-challenge.txt	2021-02-04 17:41:59.000000000 +0000
@@ -8,6 +8,12 @@
 the case where there is a device on the bus that has errata and/or bugs
 that makes standard multimaster mode not feasible.
 
+Note that this scheme works well enough but has some downsides:
+* It is nonstandard (not using standard I2C multimaster)
+* Having two masters on a bus in general makes it relatively hard to debug
+  problems (hard to tell if i2c issues were caused by one master, another, or
+  some device on the bus).
+
 
 Algorithm: