Re: kern/53795: i915drmkms causes crash on boot with Atom N270/945GSE netbook

["David H. Gutteridge" <david%gutteridge.ca@localhost>]

The following reply was made to PR kern/53795; it has been noted by GNATS.

From: "David H. Gutteridge" <david%gutteridge.ca@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: kern/53795: i915drmkms causes crash on boot with Atom
 N270/945GSE netbook
Date: Tue, 05 Feb 2019 21:17:43 -0500

 On Tue, 8 Jan 2019, at 06:40:00 +0000 (UTC), Elliott Shue wrote:
 >I did in the original report, it is an ECS E09EI6, DakTech branded in
 >my case. It is slightly oddball, with a 1.8" ZIF drive and internal
 >USB based Wifi, but I don't think the graphics are anything that
 >weird.
 
 So you did. My reading comprehension was a little off. I see I also
 missed you mentioned you had tested i915drm already. My apologies.
 
 >There is something weird going on with i915drmkms enabled because my
 >Wifi won't come up when enabled in rc.conf, I added it and sshd to
 >rc.local and that works. I should have mentioned that earlier, I am
 >not experienced enough with NetBSD to know what is going on but it
 >seems like something is halting the init.
 
 In theory, in this example, you could be hitting two different bugs:
 the DRM issue where you don't get any console output, and then an
 unrelated USB bug that triggers a kernel panic. (I say that since your
 WiFi is attached via USB.) I can sometimes reproduce a USB-related
 panic on my X110 (http://gnats.netbsd.org/53895) while using a USB WiFi
 device. I haven't isolated how to reproduce this consistently yet.
 (Sometimes, it leaves trace information in the dmesg that's logged,
 other times, nothing makes it.)
 
 >> The initial ACPI output looks weird, i.e. I doubt all those video
 >> outputs exist on the machine. I have no idea if that's anything more
 >>than a red herring, though.
  
 >There is only one video output physically, the internal LCD, it
 >doesn't even have a VGA port. I would've tried an external monitor if
 >I could. 
 
 For one thing, it's saying it can't get all the necessary data from the
 BIOS about your display hardware, so it's guessing at what it needs to
 find, but that's not uncommon. I see the same thing on my X110, not a
 showstopper in itself. (There's another recent report of an issue that
 could be related to yours, with no resolution for it, either:
 http://mail-index.netbsd.org/current-users/2019/01/12/msg034921.html)
 
 I was triaging this bug to help out, but it's probably beyond my
 knowledge to help narrow further, so I'll assign it to our main DRM
 maintainer.
 
 Dave