R36 PLUS cannot adjust the GPU frequency normally #206

Recently, while I was researching how to overclock the R36PLUS, I discovered a strange situation. The GPU was always running at the lowest frequency of 400 MHz as configured in the device tree, even though the device tree also included two other frequencies of 480 MHz and 520 MHz. I attempted to modify the scheduler to high performance, but the GPU still ran at the lowest frequency.
So I checked the logs about the GPU

ark@rg351mp:~$ dmesg | grep mali
[ 0.609533] mali ff400000.gpu: Looking up mali-supply from device tree
[ 0.609568] mali ff400000.gpu: Failed to get regulator
[ 0.614736] mali ff400000.gpu: Power control initialization failed
[ 0.916301] mali ff400000.gpu: Looking up mali-supply from device tree
[ 0.916663] mali ff400000.gpu: Failed to get leakage
[ 0.921682] mali ff400000.gpu: Looking up mali-supply from device tree
[ 0.921928] mali ff400000.gpu: pvtm-volt-sel=2
[ 0.922240] mali ff400000.gpu: avs=0
[ 0.922294] W : [File] : drivers/gpu/arm/bifrost_for_linux/platform/rk/mali_kbase_config_rk.c; [Line] : 113; [Func] : kbase_platform_rk_init(); power-off-delay-ms not available.
[ 0.922875] mali ff400000.gpu: GPU identified as 0x3 arch 7.0.9 r0p0 status 0
[ 0.923523] mali ff400000.gpu: l=0 h=2147483647 hyst=5000 l_limit=0 h_limit=0
[ 0.923704] mali ff400000.gpu: Using configured power model mali-simple-power-model, and fallback mali-simple-power-model
[ 0.924530] mali ff400000.gpu: Probed as mali0

I noticed this line

[ 0.609568] mali ff400000.gpu: Failed to get regulator

So I checked the dtb , found gpu@ff400000 node references a regulator named vdd_logic through mali-supply. Generally, the GPU should have a dedicated regulator vdd_gpu, so I looked up the technical manual of rk3326

It seems that the logic core and GPU share this regulator , So I attempted to directly delete the mali-supply property in the GPU node

Then, it worked , after I change the governor to performance in the advanced Settings, the GPU successfully reached 520Mhz

ark@rg351mp:~$ dmesg | grep mali
[ 0.607145] mali ff400000.gpu: Looking up mali-supply from device tree
[ 0.607171] mali ff400000.gpu: Looking up mali-supply property in node /gpu@ff400000 failed
[ 0.607193] mali ff400000.gpu: Continuing without Mali regulator control
[ 0.607269] mali ff400000.gpu: Failed to get leakage
[ 0.612287] mali ff400000.gpu: Looking up mali-supply from device tree
[ 0.612312] mali ff400000.gpu: Looking up mali-supply property in node /gpu@ff400000 failed
[ 0.612334] mali ff400000.gpu: Failed to get reg
[ 0.612822] mali ff400000.gpu: avs=0
[ 0.612889] W : [File] : drivers/gpu/arm/bifrost_for_linux/platform/rk/mali_kbase_config_rk.c; [Line] : 113; [Func] : kbase_platform_rk_init(); power-off-delay-ms not available.
[ 0.613173] W : [File] : drivers/gpu/arm/bifrost_for_linux/platform/rk/mali_kbase_config_rk.c; [Line] : 285; [Func] : rk_pm_enable_regulator(); no mali regulator control, no need to enable.
[ 0.613613] mali ff400000.gpu: GPU identified as 0x3 arch 7.0.9 r0p0 status 0
[ 0.614861] mali ff400000.gpu: l=0 h=2147483647 hyst=5000 l_limit=480000000 h_limit=0
[ 0.614913] mali ff400000.gpu: failed to read out thermal zone (-22)
[ 0.621542] mali ff400000.gpu: Using configured power model mali-simple-power-model, and fallback mali-simple-power-model
[ 0.622681] mali ff400000.gpu: Probed as mali0

ark@rg351mp:/sys/class/devfreq/ff400000.gpu$ cat cur_freq
520000000