Update DMAChannel.h

I'm planning to merge the teensyduino 1.20 branch of DmaSpi to master tomorrow and then you can remove that hint, or update it please.

http://forum.pjrc.com/threads/26676-Teensy3-x-strncpy_P%28%29-bug

Update DMAChannel.h

Changed  DMABaseClass::source() and destination() to use p's address instead of its value in the if-clause. Taking the value could result in unwated read operations from I/O locations, resulting in data loss.

https://groups.google.com/a/arduino.cc/d/msg/developers/ls3hkviFYM4/XWT2LbfzNcgJ

fix for (long) destinationBuffer  TCD->ATTR_DST

Was set for 16 bit size.

resync

resync

resync

http://forum.pjrc.com/threads/26064-Large-transfers-over-serial-on-Teensy-3-1
http://forum.arduino.cc/index.php/topic,165574.0.html

resync

resync

resync

resync