Re: kern/49398 (i386-current GENERIC (i915drmkms) boot hangs if monitor powered off)

["John D. Baker" <jdbaker%mylinuxisp.com@localhost>]

The following reply was made to PR kern/49398; it has been noted by GNATS.

From: "John D. Baker" <jdbaker%mylinuxisp.com@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: riastradh%NetBSD.org@localhost
Subject: Re: kern/49398 (i386-current GENERIC (i915drmkms) boot hangs if
 monitor powered off)
Date: Tue, 9 Jun 2015 22:42:38 -0500 (CDT)

 On Tue, 9 Jun 2015, John D. Baker wrote:
 
 > I have access to at least one, possibly two, other machines with intel
 > graphics that I can test.  I'm in the process of setting those up now.
 
 The first of the other machines has been set up and works properly even
 when the monitor (VGA LCD) is off:
 
 NetBSD 7.99.18 (GENERIC) #17: Tue Jun  9 16:51:47 CDT 2015
         sysop%skuld.technoskunk.fur@localhost:/d0/build/current/obj/i386/sys/arch/i386/compile/GENERIC
 [...]
 IBM 817234U (ThinkCentre S51)
 [...]
 pci0 at mainbus0 bus 0: configuration mode 1
 pci0: i/o space, memory space enabled, rd/line, rd/mult, wr/inv ok
 pchb0 at pci0 dev 0 function 0: Intel 82915P/G/GL Host (rev. 0x04)
 agp0 at pchb0: i915-family chipset
 agp0: detected 7932k stolen memory
 agp0: aperture at 0xc0000000, size 0x10000000
 i915drmkms0 at pci0 dev 2 function 0: Intel 82915G/GL Integrated Graphics Device (rev. 0x04)
 drm: Memory usable by graphics device = 256M
 drm: Supports vblank timestamp caching Rev 2 (21.10.2013).
 drm: Driver supports precise vblank timestamp query.
 i915drmkms0: interrupting at ioapic0 pin 16 (i915)
 drm: initialized overlay support
 intelfb0 at i915drmkms0
 i915drmkms0: info: registered panic notifier
 intelfb0: framebuffer at 0xdb195000, size 1280x1024, depth 32, stride 5120
 wsdisplay0 at intelfb0 kbdmux 1: console (default, vt100 emulation), using wskbd0
 wsmux1: connecting to wsdisplay0
 [...]
 
 The monitor is a Gateway FDP1730 1280x1024 VGA LCD display.  Xorg works
 very nicely without any "xorg.conf" file.  The only exception is that
 attempting to kill the Xserver with Ctrl-Alt-Backspace renders all of
 wsconsole inoperative.
 
 While I was at it, I confirmed that this system also produces unviewable
 video when the console is the serial port.  In this case, the monitor's
 on-screen display reported "Input out of range" after which its internal
 power-management put the screen to sleep.
 
 In this state, one can start the Xserver and clients and they appear
 to be running, but of course there's no visual output.
 
 
 > One other possibility has occurred to me.  Perhaps the monitor I've
 > been using is flaky (IIUC, EDID data should be readable even if the
 > monitor is off).  Unfortunately, testing the machine in question with
 > another monitor and the monitor with another machine is a rather
 > difficult undertaking.
 
 I have another project blocking the workspace, but if I can clear that
 I should be able to play a bit of Towers of Hanoi with equipment to test
 the i915 box with the CRT display and the i845 box with the LCD panel.
 
 -- 
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