3

just in order to understand I'm asking here... I get the message

$ update-initramfs -u -k all
update-initramfs: Generating /boot/initrd.img-5.9.0-1-amd64
W: Possible missing firmware /lib/firmware/i915/rkl_dmc_ver2_01.bin for module i915
update-initramfs: Generating /boot/initrd.img-5.8.0-3-amd64
W: Possible missing firmware /lib/firmware/i915/rkl_dmc_ver2_01.bin for module i915 

which makes me wonder if my hardware is correctly supported with the firmware installed. Thus I've tried to get this ver2_01 firmware, but unfortunately I cannot find it anywhere. I've non-free included in my sources, and I've also looked in the git repo git://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git, but there I only find ver2_02 for rkl_dmc.

Now, since ver2_02 is installed, can I just create a link vor ver2_01 pointing to ver2_02? Does the message above mean, that I something will not work properly - how can I check? Since i915 is related to my on-chip graphic card (to my knowledge), I'm afraid that e.g. OpenGL might not work correctly!?

Please, could someone 'shed a light' on this for me, or could even point me to a solution?

Kind Regards, George

3 Answers 3

7

rkl is apparently Rocket Lake, the codename for an Intel chipset that is supposed to be released in early 2021. So this is the Linux i915 driver already getting support for hardware that is not released yet.

The i915 driver covers a wide range of Intel iGPUs, including all the current ones and sometimes even near-future ones if they follow a design similar to their predecessors.

The kernel modules like i915 include metadata indicating the firmware files they may need: the i915 module needs to declare the firmware files for all supported Intel iGPU versions this way.

The update-initramfs tool is not smart enough to cross-check the hardware information to find out which of the various firmware files declared by the i915 driver are actually needed by your hardware, so it will simply attempt to include all of them into initramfs.

Unless you have installed firmware files for all the Intel iGPU variants, you may get some nuisance messages from update-initramfs; but if they don't refer to the iGPU/chipset version you're actually using, you can simply ignore them.

dmc in the firmware file name refers to "Display MicroController".

A code comment in Linux i915 driver says:

/**
 * DOC: csr support for dmc
 *
 * Display Context Save and Restore (CSR) firmware support added from gen9
 * onwards to drive newly added DMC (Display microcontroller) in display
 * engine to save and restore the state of display engine when it enter into
 * low-power state and comes back to normal.
 */

I did not find any indication that the DMC would be used by anything other than power saving, so even if there were any problems, they would be more likely in the domain of power saving, not OpenGL.

The patch updating the firmware version requirement from 2_01 to 2_02 was discussed in August this year so it's still pretty new. It looks like it did not get into your kernel version (5.9), but it will be in kernel version 5.10.

And, as the Rocket Lake chipset is not released yet, the rkl_dmc_ver2_01.bin might have been distributed only internally at Intel (some Intel developers also participate in Linux kernel development, you know). But for the same reason, this is unlikely to cause any problems for you, other than an extra message or two from update-initramfs.

In the unlikely case that you are actually testing pre-release hardware, you should be under a suitable NDA and you or someone in your organization should have a contact at Intel who can provide the ver2_01 firmware file for you if you really need it.

4
  • In the unlikely case that you are actually testing pre-release hardware, you should be under a suitable NDA I've googled this firmware name and he's not the only one who's having this issue - looks like it's a update-initramfs utility issue. Commented Nov 10, 2020 at 10:20
  • Wow, geat... a very detailed and comprehensive answer, THANK YOU! Honestly, I'm not testing pre-released hardwar ;) I'm still using my pretty good working horse (T470p), which has a intel on-chip graphic as well as a nvidia card (optimus). Since I use the nvidia device for 'heavy duty' application (where I need it!), I'm interested in using the capabilities of the on-chip gpu for the rest - including (somethimes) application that require OpenGL functionality.
    – George
    Commented Nov 10, 2020 at 10:35
  • To my best knowledge, the on-chip gpu also supports OpenGL 4.x, and I wanted to be sure that the FW and drivers are all working correct before I start with testing.
    – George
    Commented Nov 10, 2020 at 10:35
  • FYI: Lenovo T470p with "Intel(R) Core(TM) i7-7820HQ CPU @ 2.90GHz", "Intel Corporation HD Graphics 630 (rev 04)" and "NVIDIA Corporation GM108M [GeForce 940MX] (rev a2)"... don't hesitate to ask if you need more info!
    – George
    Commented Nov 10, 2020 at 10:37
3

Oftentimes Intel's iGPU/WiFi drivers use unreleased versions of firmware, so if everything works, there's no need to worry. Just ignore the warnings for the time being.

Also this particular firmware (name) doesn't even seem right in regard to your hardware. RKL = Rocket Lake, a CPU which hasn't even been released yet.

2

I had the same message but the installation of a mainline kernel-headers package failed because of this.

I linked rkl_dmc_ver2_01.bin to rkl_dmc_ver2_02.bin and the package installed sucessfully.

There should be no negative side-effects especially as, like it has been said above, it's not very likely that someone uses the hardware for the rkl* firmware already

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