quoted

+               if (msgs[i].flags & I2C_M_RD) {
+                       if (i2c_quirk_exceeded(len, max_read))
+                               return i2c_quirk_error(adap, &msgs[i], "msg too long");
+               } else {
+                       if (i2c_quirk_exceeded(len, max_write))
+                               return i2c_quirk_error(adap, &msgs[i], "msg too long");
+               }

What about being more verbose in the error message, specifying if it
was a read or a write message that failed?

Yes, done now. Thanks!