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Groups > linux.kernel > #1238751
| From | Jiang Liu <jiang.liu@linux.intel.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: WARNING: CPU: 4 PID: 863 at include/drm/drm_crtc.h:1577 drm_helper_choose_encoder_dpms+0x88/0x90() - evildoer found and neutralized |
| Date | 2015-10-03 09:40 +0200 |
| Message-ID | <qfpAd-3DX-17@gated-at.bofh.it> (permalink) |
| References | (6 earlier) <qe0NA-4fJ-17@gated-at.bofh.it> <qekjf-6VR-1@gated-at.bofh.it> <qeoZA-5g3-7@gated-at.bofh.it> <qet3c-2QO-19@gated-at.bofh.it> <qetwd-3ox-1@gated-at.bofh.it> |
| Organization | Intel |
On 2015/10/1 1:36, Borislav Petkov wrote:
> On Thu, Oct 01, 2015 at 01:00:44AM +0800, Jiang Liu wrote:
>> Thanks Joerg, that makes sense. If some driver tries to binding to
>> the IOMMU device, it will trigger the scenario as you described. For
>> example, Xen backend driver will try to probe all PCI devices if
>> enabled. I will do more investigation tomorrow.
>
> Right, so this fixes the issue on my box, courtesy of Joerg. WE
> basically don't disable the IRQ on MSI-enabled devices. The AMD IOMMU
> uses a barebones PCI device but not a PCI driver, which would be an
> overkill.
>
> ---
> diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c
> index 09d3afc..29ec2eb 100644
> --- a/arch/x86/pci/common.c
> +++ b/arch/x86/pci/common.c
> @@ -674,12 +674,15 @@ int pcibios_add_device(struct pci_dev *dev)
>
> int pcibios_alloc_irq(struct pci_dev *dev)
> {
> + if (pci_dev_msi_enabled(dev))
> + return 0;
We may return -EBUSY here to reject the probe operation. It
doesn't make sense to continue the probe if MSI is already enabled,
tt also helps to avoid calling pcibios_free_irq() in function
pci_device_probe().
> +
> return pcibios_enable_irq(dev);
> }
>
> void pcibios_free_irq(struct pci_dev *dev)
> {
> - if (pcibios_disable_irq)
> + if (!pci_dev_msi_enabled(dev) && pcibios_disable_irq)
The above change is not needed, pcibios_disable_irq() will
first check !pci_has_managed_irq(dev) before actually freeing
PCI irq. pci_has_managed_irq(dev) only returns true if
pcibios_alloc_irq() succeeds.
So to summary, I think we only need following change to fix the
regression:
int pcibios_alloc_irq(struct pci_dev *dev)
{
+ if (pci_dev_msi_enabled(dev))
+ return -EBUSY;
What do you think?
Thanks!
Gerry
> pcibios_disable_irq(dev);
> }
> --
>
--
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Re: WARNING: CPU: 4 PID: 863 at include/drm/drm_crtc.h:1577 drm_helper_choose_encoder_dpms+0x88/0x90() Alex Deucher <alexdeucher@gmail.com> - 2015-09-22 22:00 +0200
Re: WARNING: CPU: 4 PID: 863 at include/drm/drm_crtc.h:1577 drm_helper_choose_encoder_dpms+0x88/0x90() Alex Deucher <alexdeucher@gmail.com> - 2015-09-22 23:00 +0200
Re: WARNING: CPU: 4 PID: 863 at include/drm/drm_crtc.h:1577 drm_helper_choose_encoder_dpms+0x88/0x90() Daniel Vetter <daniel@ffwll.ch> - 2015-09-23 09:30 +0200
Re: WARNING: CPU: 4 PID: 863 at include/drm/drm_crtc.h:1577 drm_helper_choose_encoder_dpms+0x88/0x90() Borislav Petkov <bp@alien8.de> - 2015-09-23 11:10 +0200
Re: WARNING: CPU: 4 PID: 863 at include/drm/drm_crtc.h:1577 drm_helper_choose_encoder_dpms+0x88/0x90() Daniel Vetter <daniel@ffwll.ch> - 2015-09-23 16:50 +0200
Re: WARNING: CPU: 4 PID: 863 at include/drm/drm_crtc.h:1577 drm_helper_choose_encoder_dpms+0x88/0x90() Borislav Petkov <bp@alien8.de> - 2015-09-23 18:10 +0200
Re: WARNING: CPU: 4 PID: 863 at include/drm/drm_crtc.h:1577 drm_helper_choose_encoder_dpms+0x88/0x90() Borislav Petkov <bp@alien8.de> - 2015-09-23 18:20 +0200
Re: WARNING: CPU: 4 PID: 863 at include/drm/drm_crtc.h:1577 drm_helper_choose_encoder_dpms+0x88/0x90() - evildoer found and neutralized Borislav Petkov <bp@alien8.de> - 2015-09-26 18:50 +0200
Re: WARNING: CPU: 4 PID: 863 at include/drm/drm_crtc.h:1577 drm_helper_choose_encoder_dpms+0x88/0x90() - evildoer found and neutralized Jiang Liu <jiang.liu@linux.intel.com> - 2015-09-29 11:00 +0200
Re: WARNING: CPU: 4 PID: 863 at include/drm/drm_crtc.h:1577 drm_helper_choose_encoder_dpms+0x88/0x90() - evildoer found and neutralized Borislav Petkov <bp@alien8.de> - 2015-09-29 13:00 +0200
Re: WARNING: CPU: 4 PID: 863 at include/drm/drm_crtc.h:1577 drm_helper_choose_encoder_dpms+0x88/0x90() - evildoer found and neutralized Jiang Liu <jiang.liu@linux.intel.com> - 2015-09-30 09:50 +0200
Re: WARNING: CPU: 4 PID: 863 at include/drm/drm_crtc.h:1577 drm_helper_choose_encoder_dpms+0x88/0x90() - evildoer found and neutralized Joerg Roedel <joro@8bytes.org> - 2015-09-30 14:50 +0200
Re: WARNING: CPU: 4 PID: 863 at include/drm/drm_crtc.h:1577 drm_helper_choose_encoder_dpms+0x88/0x90() - evildoer found and neutralized Jiang Liu <jiang.liu@linux.intel.com> - 2015-09-30 19:10 +0200
Re: WARNING: CPU: 4 PID: 863 at include/drm/drm_crtc.h:1577 drm_helper_choose_encoder_dpms+0x88/0x90() - evildoer found and neutralized Borislav Petkov <bp@alien8.de> - 2015-09-30 19:40 +0200
Re: WARNING: CPU: 4 PID: 863 at include/drm/drm_crtc.h:1577 drm_helper_choose_encoder_dpms+0x88/0x90() - evildoer found and neutralized Joerg Roedel <joro@8bytes.org> - 2015-09-30 20:10 +0200
Re: WARNING: CPU: 4 PID: 863 at include/drm/drm_crtc.h:1577 drm_helper_choose_encoder_dpms+0x88/0x90() - evildoer found and neutralized Jiang Liu <jiang.liu@linux.intel.com> - 2015-10-03 09:40 +0200
Re: WARNING: CPU: 4 PID: 863 at include/drm/drm_crtc.h:1577 drm_helper_choose_encoder_dpms+0x88/0x90() - evildoer found and neutralized Borislav Petkov <bp@alien8.de> - 2015-10-03 11:40 +0200
Re: WARNING: CPU: 4 PID: 863 at include/drm/drm_crtc.h:1577 drm_helper_choose_encoder_dpms+0x88/0x90() - evildoer found and neutralized Joerg Roedel <joro@8bytes.org> - 2015-10-05 12:10 +0200
Re: WARNING: CPU: 4 PID: 863 at include/drm/drm_crtc.h:1577 drm_helper_choose_encoder_dpms+0x88/0x90() - evildoer found and neutralized Joerg Roedel <joro@8bytes.org> - 2015-09-30 20:10 +0200
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