GPU frequency of zhanrui chip

1. The relationship between zhanrui and Spreadtrum

---->2001 year , Establishment of Spreadtrum .

  ----->2013 year , Ziguang group Acquisition Exhibition .

    ------>2018 year 1 month , Zhan Rui , By Under Ziguang group Of Spreadtrum communication and Radico microelectronics Integrated .

So we can also say that zhanrui and Spreadtrum are one company .

2. Zhan Rui UD710 and T7510 Chip relationship

The unpublished model is called ：UD710

The final model is called ：T7510

3.GPU debugging

1. see GPU frequency range 
# cat /sys/class/devfreq/60000000.gpu/device/devfreq/60000000.gpu/simple_ondemand/available_frequencies
384000000 512000000 614400000 768000000 800000000

2. see GPU The strategy used 
# cat /sys/class/devfreq/60000000.gpu/device/devfreq/60000000.gpu/available_governors 
mtx_dvfs dcam_axi_dvfs dcam_if_dvfs isp_dvfs jpg_dvfs fd_dvfs cpp_dvfs mmsys_dvfs vdsp_dvfs vsp_dvfs dpu_dvfs sprd_governor simple_ondemand

 Be careful ：GPU Only support sprd_governor and simple_ondemand These two strategies , The others are others codec Strategy , If setting other policies is invalid .

3. Set up GPU The frequency is 800MHz
# echo 800000000 > /sys/class/devfreq/60000000.gpu/device/devfreq/60000000.gpu/min_freq
# cat min_freq 800000000
# cat /sys/class/devfreq/60000000.gpu/device/devfreq/60000000.gpu/trans_stat 
     From  :   To
           : 384000000 512000000 614400000 768000000 800000000   time(ms)
  384000000:         0         0         0         0         1   2010540
  512000000:         0         0         0         0         0         0
  614400000:         0         0         0         0         0         0
  768000000:         0         0         0         0         0         0
* 800000000:         0         0         0         0         0    318236 
// at present GPU The highest frequency is used ：800000000Hz = 800000KHz = 800MHz Rendering 


4. change GPU Strategy 
# echo simple_ondemand > /sys/class/devfreq/60000000.gpu/device/devfreq/60000000.gpu/governor
# cat /sys/class/devfreq/60000000.gpu/device/devfreq/60000000.gpu/governor
simple_ondemand