Bug 1148493

"Me too" -- the same hardware:

[root@odvarok lkundrak]# strace -ttt -f -p `pidof Xorg.bin` 2>&1 |head -n20
Process 683 attached with 2 threads
[pid   696] 1412275924.737825 futex(0x1b502b4, FUTEX_WAIT_PRIVATE, 1491, NULL <unfinished ...>
[pid   683] 1412275924.737901 ioctl(10, 0x40406469, 0x7fffe579baf0) = 0
[pid   683] 1412275924.739436 ioctl(10, 0xc0086457, 0x7fffe579baa0) = 0
[pid   683] 1412275924.739786 ioctl(10, 0x4020645d, 0x7fffe579ba80) = 0
[pid   683] 1412275924.740172 ioctl(10, 0x40406469, 0x7fffe579baf0) = 0
[pid   683] 1412275924.740914 ioctl(10, 0xc0086457, 0x7fffe579baa0) = 0
[pid   683] 1412275924.741334 --- SIGALRM {si_signo=SIGALRM, si_code=SI_KERNEL} ---
[pid   683] 1412275924.741633 rt_sigreturn() = 0
[pid   683] 1412275924.742020 ioctl(10, 0x4020645d, 0x7fffe579ba80) = 0
[pid   683] 1412275924.742421 ioctl(10, 0x40406469, 0x7fffe579baf0) = 0
[pid   683] 1412275924.742934 ioctl(10, 0xc0086457, 0x7fffe579baa0) = 0
[pid   683] 1412275924.743611 ioctl(10, 0x4020645d, 0x7fffe579ba80) = 0
[pid   683] 1412275924.743958 ioctl(10, 0x40406469, 0x7fffe579baf0) = 0
[pid   683] 1412275924.744372 ioctl(10, 0xc0086457, 0x7fffe579baa0) = 0
[pid   683] 1412275924.744803 ioctl(10, 0x4020645d, 0x7fffe579ba80) = 0
[pid   683] 1412275924.745167 ioctl(10, 0x40406469, 0x7fffe579baf0) = 0
[pid   683] 1412275924.745534 ioctl(10, 0xc0086457, 0x7fffe579baa0) = 0
[pid   683] 1412275924.745951 --- SIGALRM {si_signo=SIGALRM, si_code=SI_KERNEL} ---
[pid   683] 1412275924.746452 rt_sigreturn() = 0
[root@odvarok lkundrak]# 

(gdb) bt
#0  0x00007f14ccc85957 in ioctl () at ../sysdeps/unix/syscall-template.S:81
#1  0x00007f14c8410d6c in do_ioctl (fd=10, req=req@entry=1077961833, arg=arg@entry=0x7fffe579baf0)
    at kgem.c:212
#2  0x00007f14c84194bb in do_execbuf (execbuf=0x7fffe579baf0, kgem=0x7f14cf081000) at kgem.c:3209
#3  _kgem_submit (kgem=0x7f14cf081000) at kgem.c:3308
#4  0x00007f14c84693ad in sna_read_boxes (sna=0xa, dst=0x40406469, src_bo=0x7fffe579baf0, 
    box=0xffffffffffffffff, nbox=-1) at sna_io.c:594
#5  0x00007f14c842c5eb in _sna_pixmap_move_to_cpu (pixmap=0x1fe9a00, flags=34) at sna_accel.c:2364
#6  0x00007f14c842feb6 in sna_drawable_move_region_to_cpu (drawable=0x0, region=0x7fffe579c050, flags=65)
    at sna_accel.c:2757
#7  0x00007f14c8433899 in sna_get_image (drawable=0xa, x=0, y=-821555200, w=-1, h=-1, format=0, 
    mask=4294967295, dst=0x261da60 "") at sna_accel.c:16887
#8  0x0000000000588298 in miSpriteGetImage (pDrawable=0x1fe9a00, sx=0, sy=0, w=300, h=54, format=2, 
    planemask=4294967295, pdstLine=0x261da60 "") at misprite.c:405
#9  0x00000000004c8e8a in compGetImage (pDrawable=0x1fe9a00, sx=<optimized out>, sy=<optimized out>, 
    w=<optimized out>, h=<optimized out>, format=<optimized out>, planemask=4294967295, pdstLine=0x261da60 "")
    at compinit.c:148
#10 0x000000000043618b in DoGetImage (planemask=<optimized out>, height=<optimized out>, 
    width=<optimized out>, y=<optimized out>, x=<optimized out>, drawable=<optimized out>, 
    format=<optimized out>, client=<optimized out>) at dispatch.c:2118
#11 ProcGetImage (client=0x210e280) at dispatch.c:2181
#12 0x0000000000438fe7 in Dispatch () at dispatch.c:432
#13 0x000000000043d176 in dix_main (argc=16, argv=0x7fffe579c3d8, envp=<optimized out>) at main.c:296
#14 0x00007f14ccbaefe0 in __libc_start_main (main=0x4275f0 <main>, argc=16, argv=0x7fffe579c3d8, 
    init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffe579c3c8)
    at libc-start.c:289
#15 0x000000000042761e in _start ()
(gdb)

The problem disappeared for me when I updated to today's Git snapshot.

Maybe one of the later SNA fixes helped?

I'm seeing this hang too on my Asus P5E-VM HDMI based system which has G35 embedded graphics:

00:02.0 VGA compatible controller: Intel Corporation 82G35 Express Integrated Graphics Controller (rev 03)
00:02.1 Display controller: Intel Corporation 82G35 Express Integrated Graphics Controller (rev 03)

I'm running the same set of packages apart from a newer version of Firefox:

kernel-3.16.6-203.fc20.x86_64
kernel-3.17.1-300.fc21.x86_64
kernel-3.17.2-300.fc21.x86_64
xorg-x11-drv-intel-2.99.916-2.fc21.x86_64
firefox-33.0-1.fc21.x86_64
Linux snowman.fiddes-enterprises.com 3.17.2-300.fc21.x86_64 #1 SMP Thu Oct 30 19:23:48 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

Also forcing fbdev seems to give a working system. Prior to today (2014-11-02) the system ran F20 with no problems.

Same problem here on my Pentium D 920 system which has G65 embedded graphics after upgrading from Fedora 20 to Fedora 21 beta. When the X server is locked it does not respond to any key presses but I can still move the mouse pointer. X server also locks with other applications like Thunderbird and xmms. I haven't seen any issues with GNOME Shell, GNOME Terminal and VNC. Running Firefox from within VNC session on localhost works fine.

$ lspci | grep VGA
00:02.0 VGA compatible controller: Intel Corporation 82G965 Integrated Graphics Controller (rev 02)
$ cat /proc/cpuinfo | grep model\ name
model name	: Intel(R) Pentium(R) D CPU 2.80GHz
model name	: Intel(R) Pentium(R) D CPU 2.80GHz
$ uname -rv
3.17.2-300.fc21.x86_64 #1 SMP Thu Oct 30 19:23:48 UTC 2014
$ rpm -q kernel xorg-x11-server-common xorg-x11-drv-intel firefox
kernel-3.16.6-203.fc20.x86_64
kernel-3.16.7-200.fc20.x86_64
kernel-3.17.2-200.fc20.x86_64
kernel-3.17.2-300.fc21.x86_64
xorg-x11-server-common-1.16.1-1.fc21.x86_64
xorg-x11-drv-intel-2.99.916-2.fc21.x86_64
firefox-33.1-2.fc21.x86_64

xorg-x11-drv-intel-2.99.916-3.20141117.fc21 has been submitted as an update for Fedora 21.
https://admin.fedoraproject.org/updates/xorg-x11-drv-intel-2.99.916-3.20141117.fc21

No issues seen so far after upgrading to xorg-x11-drv-intel-2.99.916-3.20141117.fc21 (64-bit). For me the bug seems to be fixed with this update.

Update seems to fix my problems as well.

xorg-x11-drv-intel-2.99.916-3.20141117.fc21 has been pushed to the Fedora 21 stable repository.  If problems still persist, please make note of it in this bug report.

Not only firefox was causing this issue. Generally any "big app" eg eclipse, netbeans, more tabs in modori, KDE (with disabled effects!?!??!)... Thank you for fix!

*** Bug 1159799 has been marked as a duplicate of this bug. ***

In my t410 this update also fixed a bug where all the fonts were going crazy.

https://delete.fedorapeople.org/bug/