Bug 53471

Summary: Radeon card occasionally locks when enabling KMS.
Product: Drivers Reporter: Chris Rankin (rankincj)
Component: Video(DRI - non Intel)Assignee: drivers_video-dri
Status: NEW ---    
Severity: normal CC: alan, alexdeucher, szg00000
Priority: P1    
Hardware: All   
OS: Linux   
Kernel Version: 3.7.x Subsystem:
Regression: Yes Bisected commit-id:
Attachments: dmesg log showing KMS failing
dmesg log showing KMS working correctly

Description Chris Rankin 2013-02-06 21:36:25 UTC
Created attachment 92611 [details]
dmesg log showing KMS failing

This is an intermittent bug that I thought had disappeared, but is back with the 3.7.x kernel series. Basically, the KMS framebuffer sometimes fails to appear when the radeon.ko module is loaded from the initramfs.

I have attached two dmesg logs, one showing the problem and the other showing a normal boot.

The only workaround that I have found is to reboot the PC and hope that it works next time.

This particular machine has a HD4670 AGP card, but I've also a much more recent one with a PCIe v2 HD6450 that has started doing this too.

/proc/cmdline:
BOOT_IMAGE=/vmlinuz-3.7.6 root=UUID=36d22042-83b5-4ae7-a8b3-11462b2d0e4c ro rd.md=0 rd.lvm=0 rd.dm=0 elevator=cfq console=ttyS0,115200n8 console=tty0 acpi_pm_good vconsole.font=latarcyrheb-sun16 vconsole.keymap=uk rd.luks=0 LANG=en_GB.UTF-8 irqpoll=1
Comment 1 Chris Rankin 2013-02-06 21:37:06 UTC
Created attachment 92621 [details]
dmesg log showing KMS working correctly
Comment 2 Alex Deucher 2013-11-18 16:28:00 UTC
The failing log show GPU resets, so I suspect some combination of userspace drivers is causing the GPU to hang.  Is this still an issue with a newer kernel or userspace stack?
Comment 3 Chris Rankin 2013-11-18 23:33:34 UTC
This particular intermittent problem hasn't occurred again, but I can't claim to know whether it has been fixed.
Comment 4 Alex Deucher 2013-11-19 13:24:59 UTC
It's more likely due to ongoing development in the userspace drivers than the kernel.