Hi Tim, thanks for the info!
On Thu, 2020-10-01 at 11:15 +0100, Tim Gover wrote:
hdmi_enable_4k60=1 causes the firmware to select 3.3 GHz for the PLLC VCO to support a core-frequency of 550 MHz which is the minimum frequency required by the HVS at 4Kp60. The side effect is that if the display clock requirements are lower than 4Kp60 then you will see different core frequencies selected by DVFS.
If enable_uart=1 and the mini-uart is selected (default unless
What is the actual test made to check if mini-uart is selected? I can't get firmware to trigger this behaviour with 64-bit upstream kernel/dts. Note that I see the core clk setup at 200MHz just before having VC4 set it to 500MHz.
The only thing I've got on my config.txt is:
enable_uart=1 arm_64bit=1
Maybe we're missing some kind of DT alias upstream?
Regards, Nicolas
bluetooth is disabled) then the firmware will pin the core-frequency to either core_freq max (500 or 550). Although, I think there is a way of pinning it to a lower fixed frequency.
The table in overclocking.md defines options for setting the maximum core frequency but unless core_freq_min is specified DVFS will automatically pick the lowest idle frequency required by the display resolution.