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]

On Sat, Oct 03, 2015 at 03:36:35PM +0800, Jiang Liu wrote:
> 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?

Yap, that works too. I've got only this ontop of 4.3+tip:

---
diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c
index dc78a4a9a466..a4687aa6c1fb 100644
--- a/arch/x86/pci/common.c
+++ b/arch/x86/pci/common.c
@@ -675,6 +675,9 @@ int pcibios_add_device(struct pci_dev *dev)
 
 int pcibios_alloc_irq(struct pci_dev *dev)
 {
+	if (pci_dev_msi_enabled(dev))
+		return -EBUSY;
+
 	return pcibios_enable_irq(dev);
 }
 
---

and it suspend+resumed fine.

I guess it is time for Joerg to write a proper patch. :-)

Thanks.

-- 
Regards/Gruss,
    Boris.

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