vcgencmd get_config doesn't work for ":0", ":1", etc. settings

[Phlamethrower]

Describe the bug vcgencmd get_config hdmi_pixel_freq_limit:0 returns the error hdmi_pixel_freq_limit:0 is unknown, despite the fact that vcgencmd get_config int lists a value for it. The other settings with ":0" or ":1" suffixes appear to be affected in the same way. Behaviour seems to be the same regardless of whether a value for the setting is specified in config.txt (and regardless of whether the old-style hdmi_pixel_freq_limit or new-style hdmi_pixel_freq_limit:0 name is used).

To reproduce

$ vcgencmd get_config hdmi_pixel_freq_limit:0

Expected behaviour

hdmi_pixel_freq_limit:0=0x11ea1a300

(or similar), as per vcgencmd get_config int

Actual behaviour

hdmi_pixel_freq_limit:0 is unknown

System

• Which model of Raspberry Pi? Pi 4B 4GB
• Which OS and version (cat /etc/rpi-issue)?

  Raspberry Pi reference 2020-05-27
  Generated using pi-gen, https://github.com/RPi-Distro/pi-gen, 825107f04027269db77426046f5085475b1ea22f, stage5

• Which firmware version (vcgencmd version)?

  May 11 2020 18:59:41 
  Copyright (c) 2012 Broadcom
  version 21bfdeee3a6ea823e2113b983390acd1eec8edfb (clean) (release) (start)

• Which kernel version (uname -a)?

  Linux raspberrypi 4.19.118-v7l+ #1311 SMP Mon Apr 27 14:26:42 BST 2020 armv7l GNU/Linux

Also seen under RISC OS with May 27th firmware on Pi 4B & 3B

[JamesH65]

So it does. I'll take a look next week.

[bhtooefr]

This issue still seems to be present, FWIW.

• Which model of Raspberry Pi? e.g. Pi3B+, PiZeroW Pi 1B 256MB
• Which OS and version (cat /etc/rpi-issue)? RISC OS 5.28
• Which firmware version (vcgencmd version)? Both of the following versions of the firmware:

  *vcgencmd version
  Jun 10 2020 17:52:12
  Copyright (c) 2012 Broadcom
  version e46bba1638cca2708b31b9daf4636770ef981735 (clean) (release) (start)

  (version that shipped with the RISC OS 5.28 ROM images)

*vcgencmd version
Oct 22 2020 14:06:02
Copyright (c) 2012 Broadcom
version 74e754ff8947c58d2773253f77f6f68a303188f8 (clean) (release) (start)

(latest)

• Which kernel version (uname -a)?

  *FX 0
  RISC OS 5.28 (19 Oct 2020)