Bug 79004 - [BDW]the monitor cannot display X window after running command "xinit"
Summary: [BDW]the monitor cannot display X window after running command "xinit"
Alias: None
Product: DRI
Classification: Unclassified
Component: DRM/Intel (show other bugs)
Version: XOrg git
Hardware: x86-64 (AMD64) Linux (All)
: medium normal
Assignee: Intel GFX Bugs mailing list
QA Contact: Intel GFX Bugs mailing list
Depends on:
Reported: 2014-05-21 08:24 UTC by zhixinx.liu
Modified: 2014-07-11 07:38 UTC (History)
4 users (show)

See Also:
i915 platform:
i915 features:


Description zhixinx.liu 2014-05-21 08:24:29 UTC
after running command "xinit &" to start X window, system should display X window on the monitor automatically.
	1. not all BDW machine can reproduce this issue.
	2. if this issue arise, even uses older kernel and older X11R7, it also can be reproduced.
	(for example: kernel:20140227_nightly and X11R7:20140227_stable)

1. Testing Env:
kernel:	3.15.0-rc5_drm-intel-fixes_4ba480_20140521
X11R7:	X11R7.stable.2014-05-20.tar.gz

2. Testing Steps:
    1.boot up system
    2.running cmd "xinit &" to start X window
    3.check the the monitor, the X windows cannot display
        1.after running "xinit &", run command "ps aux |grep X" to check which tty are using by X(for example:tty2 )
        2.run command "chvt 2"
        3.check the the monitor, the X windows can display now.
3. Debug Information:
	(gdb) bt
	#0  0x000000372f0ebfb7 in ioctl () from /usr/lib64/libc.so.6
	#1  0x00000000004b4a99 in switch_to (vt=2,
	 from=from@entry=0x5c07b1 "xf86OpenConsole") at lnx_init.c:74
	#2  0x00000000004b4e60 in xf86OpenConsole () at lnx_init.c:197
	#3  0x0000000000490a9f in InitOutput (
	 pScreenInfo=pScreenInfo@entry=0x82a880 <screenInfo>, argc=argc@entry=2,
	 argv=argv@entry=0x7fffca1e40e8) at xf86Init.c:552
	#4  0x000000000043cf0d in dix_main (argc=2, argv=<optimized out>,
	 envp=<optimized out>) at main.c:200
	#5  0x000000372f021b75 in __libc_start_main () from /usr/lib64/libc.so.6
	#6  0x00000000004277e1 in _start ()
3. Frequency of Occurence:
machine 1:Test 5 times, and this issue arise 4 times.
machine 2:cannot reproduce this issue.
Comment 1 Chris Wilson 2014-05-21 08:33:09 UTC
It's a nasty bug.

diff --git a/drivers/tty/vt/vt_ioctl.c b/drivers/tty/vt/vt_ioctl.c
index 2bd78e2ac8ec..a7bdc4b21b49 100644
--- a/drivers/tty/vt/vt_ioctl.c
+++ b/drivers/tty/vt/vt_ioctl.c
@@ -684,7 +684,8 @@ int vt_ioctl(struct tty_struct *tty,
                        if (ret)
-                       set_console(arg);
+                       if (set_console(arg))
+                               ret = -EIO;

Turns the indefinite hang into a detectable error (and prevents X from starting) when the bug occurs.

This needs to be sent upstream.

Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jiri Slaby <jslaby@suse.cz>

and bugzilla.kernel.org
Comment 2 zhixinx.liu 2014-05-22 02:07:00 UTC
seem this patch doesn't work, verify this issue with following kernel and X11R7
kernel: the latest drm-intel-nightly(f5b0c......12be4) + Chris Wilson's patch
X11R7: X11R7.stable.2014-05-21.tar.gz

it also can be reproduced.
Comment 3 zhixinx.liu 2014-07-11 07:38:03 UTC
cannot reproduce it now, so close it. if it arise again, i will reopen it.

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