Bug 101446

Summary: radeon does not pick up an X screen, modesetting does (r600, ppc, 2nd GPU)
Product: xorg Reporter: erhard_f
Component: Server/DDX/XorgAssignee: Xorg Project Team <xorg-team>
Status: RESOLVED FIXED QA Contact: Xorg Project Team <xorg-team>
Severity: normal    
Priority: medium    
Version: 7.7 (2012.06)   
Hardware: PowerPC   
OS: All   
Whiteboard:
i915 platform: i915 features:
Attachments:
Description Flags
xorg.log with "radeon" driver
none
xorg.log with "modesetting" driver
none
dmesg output none

Description erhard_f 2017-06-15 11:59:46 UTC
Created attachment 131976 [details]
xorg.log with "radeon" driver

My setup is a PowerMac 11,2 G5 with 2 graphic cards, a Nvidia GT6600 (1st PCIe-slot, Mac-BIOS) and a Radeon 5450 (2nd PCIe-slot, x86-BIOS). I need the Nvidia for the OpenFirmware bootmenu and booting the G5 up. I want to drive X with the Radeon only. Which is possible using "modesetting", but not with "radeon".

I needed "video=offb:off video=nouveaufb:off video=radeonfb:off nouveau.modeset=0 radeon.modeset=1" as kernel boot parameter to get the framebuffer on the Radeon running as /dev/fb0.

To get X running I needed this minimal /etc/X11/xorg.conf:
Section "ServerFlags"
    Option "AutoAddGPU" "false"    
EndSection

Section "Device"
    Identifier             "Card_x86"
    Driver                 "radeon"
#    Driver                 "modesetting"
    BusID                  "PCI:6:0:0"
EndSection

This setup works with modesetting picking up a screen. So I guess I am missing some important detail, which modesetting generously overlooks or it's a bug of the radeon driver.
Comment 1 erhard_f 2017-06-15 12:00:30 UTC
Created attachment 131977 [details]
xorg.log with "modesetting" driver
Comment 2 erhard_f 2017-06-15 12:01:34 UTC
Created attachment 131978 [details]
dmesg output
Comment 3 Michel Dänzer 2017-06-16 03:14:39 UTC
(In reply to erhard_f from comment #0)
>     BusID                  "PCI:6:0:0"

Does it work with

     BusID                  "PCI:6@1:0:0"

instead?
Comment 4 erhard_f 2017-06-16 12:33:57 UTC
It does. Thanks!
Comment 5 Michel Dänzer 2017-06-18 02:42:38 UTC
Glad to hear it's working.

I'm going to fix up the Xorg documentation to properly reflect how the PCI domain can be specified.
Comment 6 erhard_f 2017-06-19 12:13:55 UTC
That would be a good solution. After all the man-pages are the first place to look when something does not work as expected.
Comment 7 Michel Dänzer 2017-06-21 01:35:04 UTC
Now documented in the xorg.conf manpage with https://cgit.freedesktop.org/xorg/xserver/commit/?id=3b0fd9421add9f0ca8958ced0f39b2da21143c22 .

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