Re: kern/49285

[Patrick Welche <prlw1%cam.ac.uk@localhost>]

The following reply was made to PR kern/49285; it has been noted by GNATS.

From: Patrick Welche <prlw1%cam.ac.uk@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: kern/49285
Date: Mon, 24 Nov 2014 13:17:55 +0000

 With recent -current/amd64 (as per 18 Nov current-users posting), this
 pineview based computer now panics on boot in:
 
 ffffff81342838
 curlwp 0xffffffff810d74a0 pid 0.1 lowest kstack 0xffffffff8133f2c0
 kernel: page fault trap, code=0
 Stopped in pid 0.1 (system) at netbsd:device_is_a+0x4: movq 20(%rdi),%rax
  
 device_is_a()
 intel_opregion_init()
 i915_driver_load()
 drm_dev_register()
 drm_pci_attach()
 i915drmkms_attach()
 config_attach_loc()
 pci_probe_device()
 pci_enumerate_bus()
 pcirescan()
 pciattach()
 config_attach_loc()
 mp_pci_scan()
 mainbus_attach()
 config_attach_loc()
 cpu_configure()
 main()
 
 The problem occurs in intel_didl_outputs, because
 drm_device dev -> pci_dev pdev -> acpi_devnode pd_ad is NULL
 
 This is because acpivga is not attached, because none of
 _DOS, _DOD, _ROM, _GPD, _SPD, _VPO
 are in the acpi tables, though it appears to have an 
 
     Scope (_SB.PCI0)
     {
         Device (GFX0)
         {
             Name (_ADR, 0x00020000)  // _ADR: Address
             OperationRegion (IGDM, SystemMemory, 0x7F5BE0F4, 0x2000)
             Field (IGDM, AnyAcc, NoLock, Preserve)
             {
                 SIGN,   128, 
                 SIZE,   32, 
                 OVER,   32, 
                 SVER,   256, 
 ...
 (I see GXFC GEFC SCIS GSSE SCIE GESF GBDA.* CLID IBTT IPSC IPAT IDVM IDVS PAVP
 none exhaustive list)
 
 Presumably, that's why we end up in intel_opregion_init.