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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
To: Joerg Roedel <joro@8bytes.org>
References: <20150923160621.GA3446@pd.tnic> <20150923161839.GB3446@pd.tnic>
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Cc: Borislav Petkov <bp@alien8.de>, Daniel Vetter <daniel@ffwll.ch>,
        Thomas Gleixner <tglx@linutronix.de>,
        Bjorn Helgaas <bhelgaas@google.com>,
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From: Jiang Liu <jiang.liu@linux.intel.com>
Organization: Intel
Message-ID: <5613C8E7.8000308@linux.intel.com>
Date: Tue, 6 Oct 2015 21:13:11 +0800
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On 2015/10/5 18:03, Joerg Roedel wrote:
> 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?
Hi Joerg,
	We are on leave for Chinese National Holiday and has limited
access to my working environment. It would be appreciated if you could
help to send out a patch for it. Otherwise I will send out a patch
within 2-3 days.
Thanks!
Gerry