This reverts commit 9e467a764b.
The Raspberry Pi firmware recently switched to building from the common
firmware branch. This introduces changes in the core clock handling,
causing various issues.
E.g. enable_uart=1 no longer fixes the core clock frequency to 250MHz.
When the disable-bt DT overlay is not loaded, the core clock frequency
is increased to 400MHz. As a result, the UART baud rate is no longer
correct, and this causes garbled serial console, or communication
problems with HATs that use the UART.
As a workaround, the core clock could be fixed to 250MHz by adding
'core_freq=250' in /boot/config.txt, but as there appear to be other
issues than just the UART being broken, the safer bet is to revert the
firmware for now.
Upstream bug: https://github.com/raspberrypi/firmware/issues/1376
Signed-off-by: Stijn Tintel <stijn@linux-ipv6.be>
Acked-by: Álvaro Fernández Rojas <noltari@gmail.com>
afdc413d9d