xsrc/55853: [dM] xdpyinfo sometimes loses output

[Mouse <mouse%Rodents-Montreal.ORG@localhost>]

>Number:         55853
>Category:       xsrc
>Synopsis:       Under some circumstances, xdpyinfo prints nothing.
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    xsrc-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Dec 09 02:40:00 +0000 2020
>Originator:     Mouse
>Release:        NetBSD 9.1
>Organization:
	Dis-
>Environment:
System: NetBSD Aaeon-9.Rodents-Montreal.ORG 9.1 NetBSD 9.1 (GEN91) #6: Tue Dec 8 10:08:26 EST 2020 mouse%Aaeon-9.Rodents-Montreal.ORG@localhost:/home/mouse/kbuild/GEN91 amd64
Architecture: x86_64
Machine: amd64
>Description:
	Under certain circumstances, xdpyinfo unexpectedly produces no
	output.  My impression of the circumstances is "stdout isn't a
	tty", but that's just a guess.
>How-To-Repeat:
	On a 9.1 system, start X.
	Run "/usr/X11R7/bin/xdpyinfo".
	I see normal-looking output.
	Run "/usr/X11R7/bin/xdpyinfo | cat".
	I see no output.
	So far, script(1), as in "script -c xdpyinfo", is the only way
	I've found to capture xdpyinfo output on 9.1.

	Given how many layers are between the display and xdpyinfo's
	stdout, I am inclined to doubt the video hardware is relevant.
	In case anyone cares, though, here is what looks to me like the
	relevant lines from /var/run/dmesg.boot.  I can supply more if
	someone tells me what to look for.

	acpivga0 at acpi0 (GFX0): ACPI Display Adapter
	acpiout0 at acpivga0 (DD01, 0x0100): ACPI Display Output Device
	acpiout1 at acpivga0 (DD02, 0x0002): ACPI Display Output Device
	acpiout2 at acpivga0 (DD03, 0x0300): ACPI Display Output Device
	acpiout3 at acpivga0 (DD04, 0x0301): ACPI Display Output Device
	acpiout4 at acpivga0 (DD05, 0x0302): ACPI Display Output Device
	acpiout5 at acpivga0 (DD06, 0x0303): ACPI Display Output Device
	acpiout6 at acpivga0 (DD07, 0x0304): ACPI Display Output Device
	acpiout7 at acpivga0 (DD08, 0x0305): ACPI Display Output Device
	acpiout8 at acpivga0 (DD09, 0x0009): ACPI Display Output Device
	acpiout9 at acpivga0 (DD0A, 0x000a): ACPI Display Output Device
	acpiout10 at acpivga0 (DD0B, 0x000b): ACPI Display Output Device
	acpiout11 at acpivga0 (DD0C, 0x000c): ACPI Display Output Device
	acpiout12 at acpivga0 (DD0D, 0x000d): ACPI Display Output Device
	acpiout13 at acpivga0 (DD0E, 0x000e): ACPI Display Output Device
	acpiout14 at acpivga0 (DD0F, 0x000f): ACPI Display Output Device
	acpiout15 at acpivga0 (DD1F, 0x0400): ACPI Display Output Device
	acpiout15: brightness levels: [0-100]
	acpiout16 at acpivga0 (SKC0, 0xca00): ACPI Display Output Device
	acpivga0: connected output devices:
	acpivga0:   0x0400 (acpiout15): Unknown Output Device, head 0

	i915drmkms0 at pci0 dev 2 function 0: vendor 8086 product 5912 (rev. 0x04)

	uhidev0 at uhub1 port 3 configuration 1 interface 0
	uhidev0: PixArt (0x93a) USB Optical Mouse (0x2510), rev 2.00/1.00, addr 1, iclass 3/1
	ums0 at uhidev0: 3 buttons and Z dir
	wsmouse0 at ums0 mux 2

	uhidev1 at uhub1 port 5 configuration 1 interface 0
	uhidev1: Gaming KB (0x258a) Gaming KB (0x1006), rev 1.10/1.05, addr 2, iclass 3/1
	ukbd0 at uhidev1
	wskbd0 at ukbd0: console keyboard
	uhidev2 at uhub1 port 5 configuration 1 interface 1
	uhidev2: Gaming KB (0x258a) Gaming KB (0x1006), rev 1.10/1.05, addr 2, iclass 3/1
	uhidev2: 8 report ids
	uhid0 at uhidev2 reportid 1: input=1, output=0, feature=0
	uhid1 at uhidev2 reportid 2: input=2, output=0, feature=0
	uhid2 at uhidev2 reportid 5: input=0, output=0, feature=5
	ukbd1 at uhidev2 reportid 6
	ukbd1: autoconfiguration error: attach failed, key code size != 8
	ukbd2 at uhidev2 reportid 7
	wskbd1 at ukbd2 mux 1
	ukbd3 at uhidev2 reportid 8
	wskbd2 at ukbd3 mux 1

	kern info: [drm] Memory usable by graphics device = 4096M
	kern info: [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
	kern info: [drm] Driver supports precise vblank timestamp query.
	kern info: [drm] failed to find VBIOS tables
	i915drmkms0: interrupting at ioapic0 pin 16 (i915drmkms0)
	kern info: [drm] failed to retrieve link info, disabling eDP
	kern error: [drm:(/sys/external/bsd/drm2/dist/drm/i915/i915_drv.c:636)i915_firmware_load_error_print] *ERROR* failed to load firmware i915/kbl_dmc_ver1.bin (0)
	kern error: [drm:(/sys/external/bsd/drm2/dist/drm/i915/i915_drv.c:651)i915_firmware_load_error_print] *ERROR* kern error: [drm:(/sys/external/bsd/drm2/dist/drm/i915/intel_guc_loader.c:560)guc_fw_fetch] *ERROR* Failed to fetch GuC firmware from i915/kbl_guc_ver9_14.bin (error -2)
	The driver is built-in, so to load the firmware you need to
	include it either in the kernel (see CONFIG_EXTRA_FIRMWARE) or
	in your initrd/initramfs image.
	kern error: [drm:(/sys/external/bsd/drm2/dist/drm/i915/i915_gem.c:5417)i915_gem_init_hw] *ERROR* Failed to initialize GuC, error -5 (ignored)
	kern info: [drm] GMBUS [i915 gmbus dpd] timed out, falling back to bit banging on pin 6
	intelfb0 at i915drmkms0
	intelfb0: framebuffer at 0xffffab8067718000, size 1280x1024, depth 32, stride 5120
	warning: /sys/external/bsd/drm2/dist/drm/i915/intel_pm.c:3624: WARN_ON(!wm_changed)wsdisplay0 at intelfb0 kbdmux 1: console (default, vt100 emulation), using wskbd0
	wsmux1: connecting to wsdisplay0
	wskbd1: connecting to wsdisplay0
	wskbd2: connecting to wsdisplay0
	kern info: [drm] RC6 on
>Fix:
	I have no idea, beyond "don't try to use xdpyinfo on 9.1", which
	is less than tremendously helpful.