drm-current-kmod-4.16.g20190424 hangs

[Tycho Nightingale]

Hi,

> On Apr 26, 2019, at 4:39 PM, Andrey Fesenko <f0andrey at gmail.com> wrote:
> 
> On Fri, Apr 26, 2019 at 6:23 PM Johannes Lundberg <johalun0 at gmail.com> wrote:
>> 
>> From https://reviews.freebsd.org/D19845  Can you try the sysctls
>> suggested there?
>> 
> 
> hw.busdma.default="bounce" and hw.dmar.enable="0" ? both not exist
> 
> attach debug dmesg
> <dmesg.boot>

What are your BIOS settings for VT-d?  I see an ACPI DMAR table being reported.  As kib@ noted in https://reviews.freebsd.org/D19845: it’s not to be a surprise that "Intel GPU does not work with the DMAR enabled”.

As a first step please make sure that VT-d is disabled.  Then proceed to enabling it in identity mapped mode and finally in re-mapped mode.  That should give some additional insight into the culprit e.g. the device not being IOMMU compatible or the driver not being IOMMU compatible or something else entirely.

Tycho