Purchase Rock64 V3?

[mcerveny]

TL;DR: UHS-I modes ? Yes ! It is working with factory integrated HW patch and patch to DTS. My cheap SanDisk Ultra "speed up to 80 MB/s" (UHS-I).

Code:

# iozone -e -I -a -s 100M -r 4k -r 1024k -i 0 -i 1 -i 2
<snip>
                                                              random    random     bkwd    record    stride                                    
              kB  reclen    write  rewrite    read    reread    read     write     read   rewrite      read   fwrite frewrite    fread  freread
          102400       4     4462     4574    12393    12390     9799     5164                                                          
          102400    1024    12418    26892    67185    67292    66996    30158

Long version:

• * There is design fault in official "version 3 production schematics". The embedded diode in Q8502 changes FET to magic smoke or any component on 1.8V supply (VCC_18) not aware about 2.7V (3.3V - Source-Drain Diode Forward Voltage). Maybe published schema is total fake to disable copying (see also difference in 5V PIN2+PIN4).
  
  
  
  
• * Fault is resolved by factory patch (replaced Q8502 with some other rotated transistor and pullup resistor).
  
  
  
  
• * I had to prepare patch to DTS to activate voltage switching and enable UHS modes. This patch is not in standard distributions now.
  
  
• * Some testing and observation with patch.
  
  Code:

  # ### switched to 1.8V (gpio-30 is hi)
# head -4 /sys/kernel/debug/gpio
GPIOs 0-31, platform/pinctrl, gpio0:
gpio-0   (                    |vcc_host_5v         ) out hi    
gpio-2   (                    |vcc_host1_5v        ) out lo    
gpio-30  (                    |?                   ) out hi    

# ### vccio3 domain switched to 1.8V
# tail -4 /sys/kernel/debug/regulator/regulator_summary
vccq_sd                          1    3      0  1800mV     0mA  1800mV  3300mV
    ff500000.dwmmc                                               1800mV  1950mV
    ff100000.syscon:io-domains                                      0mV     0mV
    deviceless                                                      0mV     0mV

# ### mmc1 (sdcard) is running 150 MHz
# cat /sys/kernel/debug/mmc1/clock
150000000

# ### booted to ultra high speed
# dmesg | grep mmc1      
[    4.379677] mmc_host mmc1: Bus speed (slot 0) = 400000Hz (slot req 400000Hz, actual 400000HZ div = 0)
[    4.520429] mmc_host mmc1: Bus speed (slot 0) = 150000000Hz (slot req 150000000Hz, actual 150000000HZ div = 0)
[    4.913212] mmc1: new ultra high speed SDR104 SDHC card at address aaaa
[    4.917711] mmcblk1: mmc1:aaaa SC16G 14.8 GiB
  
  
• * There are more tests with "Samsung EVO UHS-I (orange)". Also with 200MHz because Synopsys DesignWare Mobile Storage Host Controller was designed so as I wrote elsewhere.
  
  Code:

  # ### without patch
# dmesg | grep mmc1
[    3.529051] mmc_host mmc1: Bus speed (slot 0) = 400000Hz (slot req 400000Hz, actual 400000HZ div = 0)
[    3.581582] mmc_host mmc1: Bus speed (slot 0) = 50000000Hz (slot req 50000000Hz, actual 50000000HZ div = 0)
[    3.581652] mmc1: new high speed SDHC card at address 0001
[    3.582126] mmcblk1: mmc1:0001 BB1QT 29.8 GiB

# iozone -e -I -a -s 100M -r 4k -r 1024k -i 0 -i 1 -i 2
                                                              random    random     bkwd    record    stride                                    
              kB  reclen    write  rewrite    read    reread    read     write     read   rewrite      read   fwrite frewrite    fread  freread
          102400       4     1876     2460     7732     7751     8763     1701                                                          
          102400    1024    17982    13841    23239    23259    23261    12913                                                          

# ### with patch
# dmesg | grep mmc1
[    3.881125] mmc_host mmc1: Bus speed (slot 0) = 400000Hz (slot req 400000Hz, actual 400000HZ div = 0)
[    3.950459] mmc_host mmc1: Bus speed (slot 0) = 150000000Hz (slot req 150000000Hz, actual 150000000HZ div = 0)
[    4.465921] mmc1: new ultra high speed SDR104 SDHC card at address 0001
[    4.494979] mmcblk1: mmc1:0001 BB1QT 29.8 GiB

# iozone -e -I -a -s 100M -r 4k -r 1024k -i 0 -i 1 -i 2
                                                              random    random     bkwd    record    stride                                    
              kB  reclen    write  rewrite    read    reread    read     write     read   rewrite      read   fwrite frewrite    fread  freread
          102400       4     3781     3598    14463    14509    14485     2230                                                          
          102400    1024    28554    29160    67172    67270    67152    19281                                                          

# ### with "200MHz" patch (not recommended)
# cat 200.patch
diff --git a/arch/arm64/boot/dts/rockchip/rk3328-rock64.dts b/arch/arm64/boot/dts/rockchip/rk3328-rock64.dts
index 9d848967..2b15b339 100644
--- a/arch/arm64/boot/dts/rockchip/rk3328-rock64.dts
+++ b/arch/arm64/boot/dts/rockchip/rk3328-rock64.dts
@@ -698,7 +698,7 @@
        cap-mmc-highspeed;
        cap-sd-highspeed;
        disable-wp;
-       max-frequency = <150000000>;
+       max-frequency = <200000000>;
        num-slots = <1>;
        pinctrl-names = "default";
        pinctrl-0 = <&sdmmc0_clk &sdmmc0_cmd &sdmmc0_dectn &sdmmc0_bus4>;

# dmesg | grep mmc1
[    3.333112] mmc_host mmc1: Bus speed (slot 0) = 400000Hz (slot req 400000Hz, actual 400000HZ div = 0)
[    3.402596] mmc_host mmc1: Bus speed (slot 0) = 200000000Hz (slot req 200000000Hz, actual 200000000HZ div = 0)
[    3.793574] mmc1: new ultra high speed SDR104 SDHC card at address 0001
[    3.794066] mmcblk1: mmc1:0001 BB1QT 29.8 GiB

# iozone -e -I -a -s 100M -r 4k -r 1024k -i 0 -i 1 -i 2
                                                              random    random     bkwd    record    stride                                    
              kB  reclen    write  rewrite    read    reread    read     write     read   rewrite      read   fwrite frewrite    fread  freread
          102400       4     4024     3762    15374    15388    15330     1988                                                          
          102400    1024    29919    30415    86725    87439    86829    17539

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