X using radeon is refusing to start

[Michel Dänzer]

On 06.02.2015 17:29, Chris Wilson wrote:
> On Fri, Feb 06, 2015 at 11:51:55AM +0900, Michel Dänzer wrote:
>> On 06.02.2015 09:10, Andy Lutomirski wrote:
>>> I just started getting X failures that say:
>>>
>>> [   739.208] (EE) RADEON(0): [drm] failed to set drm interface version.
>>>
>>> I'm not sure what triggered it.
>>>
>>> dmesg says:
>>>
>>> [  740.156499] [drm:drm_stub_open]
>>> [  740.156502] [drm:drm_open_helper] pid = 2170, minor = 0
>>> [  740.156541] [drm:drm_ioctl] pid=2170, dev=0xe200, auth=1,
>>> DRM_IOCTL_MODE_GETRESOURCES
>>> [  740.156557] [drm:drm_ioctl] pid=2170, dev=0xe200, auth=1,
>>> DRM_IOCTL_MODE_GETRESOURCES
>>> [  740.156575] [drm:drm_release] open_count = 2
>>> [  740.156577] [drm:drm_release] pid = 2170, device = 0xe200, open_count = 2
>>> [  740.158548] [drm:drm_ioctl] pid=2170, dev=0xe200, auth=1,
>>> DRM_IOCTL_SET_VERSION
>>> [  740.158549] [drm:drm_ioctl] ret = -13
>>> [  740.159612] [drm:drm_framebuffer_reference] ffff8804457110a0: FB ID: 83 (3)
>>>
>>> -13 means -EACCES.
>>
>> We'd need to see dmesg from the beginning to be sure, but it looks like
>> something (maybe plymouth or whatever boot splash you're using?) is
>> keeping the DRM device open, so Xorg doesn't become DRM master.
> 
> The trick is to inspect /sys/kernel/debug/dri/%d/clients at the time it
> fails and see who the kernel thinks is DRM_MASTER.

That's a neat trick, thanks.


-- 
Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer