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Date: Mon, 5 Oct 2015 12:03:55 +0200
From: Joerg Roedel <joro@8bytes.org>
To: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>, Daniel Vetter <daniel@ffwll.ch>,
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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
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Hi Jiang,

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

Yes, that works too and has the added benefit that no driver can attach
to the iommu device and get in the way of the driver.

Will you send the patch for this change or should I do it?



	Joerg