X11 error: "(KMS) drm report modesetting isn't supported"

lowley · n00b Joined: 22 Jul 2016 Posts: 47

hello

I am a newbie about gentoo and I'm trying to install gentoo on an old computer.
the computer is a dell inspiron 5150c, with a video card ATI Radeon X600.

during the installation of gentoo, I decided to set the profile to ".../desktop/plasma", I updated the @world (which took me 1 day!), and got a brand new gentoo in console mode.

I would like to swap to plasma, and for this I read I had to install X11.

it is now installed, but I can't start it using "startx", because I get this error:

eccerr0r · Posted: Fri Jul 22, 2016 6:50 pm Post subject:

Odd... shouldn't have to explicitly say you want framebuffer support in the kernel options. Try a fresh kernel config and just specify that you want DRI support in kernel and let the kernel enable any fbcon options that are necessary.

You should see your video change modes upon boot in either way, but you should not be using the regular fbcon driver, the DRI driver should be used.

If you want a stopgap solution you could install the X11 VIDEO_CARDS=fbcon driver though that would be very slow. Better to get radeon working.

Posting your kernel's .config file somewhere could be helpful.
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lowley · n00b Joined: 22 Jul 2016 Posts: 47

hello, thank you for your answer.

here is my kernel config file : http://pastebin.com/GRMqqJXG

for other points, I am sorry but I don't really understand you.

what is DRI? it is for Driver?
how can I grab a fresh .config file? Won't it break my system?
I'm afraid of fbcon driver, if you say it will slow the system; indeed I wonder wether plasma is too recent for y old computer and my old video card...

sorry if it is trivial to you but could you give me some concrete statements?

olivier

eccerr0r · Posted: Fri Jul 22, 2016 7:44 pm Post subject:

Set this to 'N' in your kernel config:

CONFIG_DRM_RADEON_UMS=y

DRI is the Direct Rendering Infrastructure. I tend to use it instead of "DRM" though Direct Rendering Manager is more appropriate at times. However I don't like the other interpretation of "DRM" implying copyright problems...

I was worried you set some of the FBCON settings but it looks like you didn't so you may not need to start with a fresh .config again.
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lowley · n00b Joined: 22 Jul 2016 Posts: 47

ok, I am compiling the kernel now... let's wait and see

lowley · n00b Joined: 22 Jul 2016 Posts: 47

oh no! same error, here's what I did : I edited .config in /usr/src/linux, searched for "CONFIG_DRM_RADEON_UMS" and set it to "N", but when entered "make && modules_install", I get a warning asking me to choose which option for CONFIG_DRM_RADEON_UMS; I entered "N" but I fear it stands for "New".
I will try to set it to "not set".

olivier

EDIT : back from .config : it was set to ... not set.
then I don't know how to continue.

Logicien · Posted: Fri Jul 22, 2016 9:22 pm Post subject:

Have-you read radeon - Gentoo Wiki? The Linux Radeon support need firmware files to work. If you put the Radeon support with KMS in the kernel image, the firmware files must be include in the kernel image too. If you compile the Radeon support in module and use an initramfs with the radeon module in, the firmware files must be in the initramfs too. If you wait that the Linux kernel access the real root partition for it to load the radeon module, you must have the firmware files in /lib/firmware/radeon.

A principle I respect is to give to a support anything it need when it probe the device it drive. If it miss something, here firmware files, the probe will probably fail. You have several ways to get Radeon KMS support. The earlier you can get it is to put the Radeon support in the kernel image with the firmware files in too. Than you get a frambuffer console when the Linux kernel is load. Than Xorg should start using the X radeon module with KMS support.

You can use dracut to create an initramfs with the radeon module in. It should include the needed firmware files in too if they are emerge. Than use this initramfs with your Linux kernel image with your bootloader. You need to emerge the radeon-ucode package in any case. Otherwise, you will have to use an other framebuffer suppport than Radeon and will not have KMS support.
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ct85711 · Veteran Joined: 27 Sep 2005 Posts: 1791

to help clear up some of the confusion that you have on the kernel config.

When you set something to Y, you are mean you want that option compiled into the kernel
M means you want it compiled as an module that the kernel can load when needed
N means you do NOT want this option, and the kernel will not compile that at all.

Just because you enable support for something (either built in or as an module) does not mean the kernel will use it. You can perfectly well make a kernel that supports everything (this is about what a binary distro does for their kernels, they make a kernel that supports most stuff, so most people can use it). However, just enabling everything does increase the kernel's size, and potentially increasing the boot time.

Another note, after you recompile the kernel, be sure that your boot partition is mounted before installing the kernel and you will need to reboot to use the new kernel. Just because you did not mount the boot partition, does not mean you won't have a /boot folder. The contents of /boot may be different than when you have boot partition mounted.

NeddySeagoon · Posted: Fri Jul 22, 2016 9:34 pm Post subject:

lowley,

What does

Hu · Moderator Joined: 06 Mar 2007 Posts: 21602

eccerr0r · Posted: Sat Jul 23, 2016 3:21 pm Post subject:

You can usually see if a firmware file is missing by inspecting the 'dmesg' output. The kernel should give an error if it tried to load a firmware file and failed.
_________________
Intel Core i7 2700K/Radeon R7 250/24GB DDR3/256GB SSD
What am I supposed watching?