#
# Asynchronous Transfer Mode (ATM)
#

config ATM
	tristate "Asynchronous Transfer Mode (ATM)"
	---help---
	  ATM is a high-speed networking technology for Local Area Networks
	  and Wide Area Networks.  It uses a fixed packet size and is
	  connection oriented, allowing for the negotiation of minimum
	  bandwidth requirements.

	  In order to participate in an ATM network, your Linux box needs an
	  ATM networking card. If you have that, say Y here and to the driver
	  of your ATM card below.

	  Note that you need a set of user-space programs to actually make use
	  of ATM.  See the file <file:Documentation/networking/atm.txt> for
	  further details.

config ATM_CLIP
	tristate "Classical IP over ATM"
	depends on ATM && INET
	help
	  Classical IP over ATM for PVCs and SVCs, supporting InARP and
	  ATMARP. If you want to communication with other IP hosts on your ATM
	  network, you will typically either say Y here or to "LAN Emulation
	  (LANE)" below.

config ATM_CLIP_NO_ICMP
	bool "Do NOT send ICMP if no neighbour"
	depends on ATM_CLIP
	help
	  Normally, an "ICMP host unreachable" message is sent if a neighbour
	  cannot be reached because there is no VC to it in the kernel's
	  ATMARP table. This may cause problems when ATMARP table entries are
	  briefly removed during revalidation. If you say Y here, packets to
	  such neighbours are silently discarded instead.

config ATM_LANE
	tristate "LAN Emulation (LANE) support"
	depends on ATM
	help
	  LAN Emulation emulates services of existing LANs across an ATM
	  network. Besides operating as a normal ATM end station client, Linux
	  LANE client can also act as an proxy client bridging packets between
	  ELAN and Ethernet segments. You need LANE if you want to try MPOA.

config ATM_MPOA
	tristate "Multi-Protocol Over ATM (MPOA) support"
	depends on ATM && INET && ATM_LANE!=n
	help
	  Multi-Protocol Over ATM allows ATM edge devices such as routers,
	  bridges and ATM attached hosts establish direct ATM VCs across
	  subnetwork boundaries. These shortcut connections bypass routers
	  enhancing overall network performance.

config ATM_BR2684
	tristate "RFC1483/2684 Bridged protocols"
	depends on ATM && INET
	help
	  ATM PVCs can carry ethernet PDUs according to RFC2684 (formerly 1483)
	  This device will act like an ethernet from the kernels point of view,
	  with the traffic being carried by ATM PVCs (currently 1 PVC/device).
	  This is sometimes used over DSL lines.  If in doubt, say N.

config ATM_BR2684_IPFILTER
	bool "Per-VC IP filter kludge"
	depends on ATM_BR2684
	help
	  This is an experimental mechanism for users who need to terminate a
	  large number of IP-only vcc's.  Do not enable this unless you are sure
	  you know what you are doing.
 value='committer'>committer</option>
<option value='range'>range</option>
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<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/commit/?h=nds-private-remove&amp;id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>root</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include?h=nds-private-remove&amp;id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>include</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include/trace?h=nds-private-remove&amp;id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>trace</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include/trace/events?h=nds-private-remove&amp;id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>events</a>/<a href='/cgit.cgi/linux/net-next.git/commit/include/trace/events/intel-sst.h?h=nds-private-remove&amp;id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>intel-sst.h</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='h' value='nds-private-remove'/><input type='hidden' name='id' value='39cb2c9a316e77f6dfba96c543e55b6672d5a37e'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-01-29 13:50:06 -0800</td></tr>
<tr><th>committer</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-01-29 13:50:06 -0800</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/trace/events/intel-sst.h?h=nds-private-remove&amp;id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>39cb2c9a316e77f6dfba96c543e55b6672d5a37e</a> (<a href='/cgit.cgi/linux/net-next.git/patch/include/trace/events/intel-sst.h?id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?h=nds-private-remove&amp;id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>98fe974ee4e20121253de7f61fc8d01bdb3821c1</a> /<a href='/cgit.cgi/linux/net-next.git/tree/include/trace/events/intel-sst.h?h=nds-private-remove&amp;id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>include/trace/events/intel-sst.h</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/include/trace/events/intel-sst.h?h=nds-private-remove&amp;id=2c5d9555d6d937966d79d4c6529a5f7b9206e405'>2c5d9555d6d937966d79d4c6529a5f7b9206e405</a> (<a href='/cgit.cgi/linux/net-next.git/diff/include/trace/events/intel-sst.h?h=nds-private-remove&amp;id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e&amp;id2=2c5d9555d6d937966d79d4c6529a5f7b9206e405'>diff</a>)</td></tr></table>
<div class='commit-subject'>drm/i915: Check for NULL i915_vma in intel_unpin_fb_obj()</div><div class='commit-msg'>I've seen this trigger twice now, where the i915_gem_object_to_ggtt()
call in intel_unpin_fb_obj() returns NULL, resulting in an oops
immediately afterwards as the (inlined) call to i915_vma_unpin_fence()
tries to dereference it.

It seems to be some race condition where the object is going away at
shutdown time, since both times happened when shutting down the X
server.  The call chains were different:

 - VT ioctl(KDSETMODE, KD_TEXT):

    intel_cleanup_plane_fb+0x5b/0xa0 [i915]
    drm_atomic_helper_cleanup_planes+0x6f/0x90 [drm_kms_helper]
    intel_atomic_commit_tail+0x749/0xfe0 [i915]
    intel_atomic_commit+0x3cb/0x4f0 [i915]
    drm_atomic_commit+0x4b/0x50 [drm]
    restore_fbdev_mode+0x14c/0x2a0 [drm_kms_helper]
    drm_fb_helper_restore_fbdev_mode_unlocked+0x34/0x80 [drm_kms_helper]
    drm_fb_helper_set_par+0x2d/0x60 [drm_kms_helper]
    intel_fbdev_set_par+0x18/0x70 [i915]
    fb_set_var+0x236/0x460
    fbcon_blank+0x30f/0x350
    do_unblank_screen+0xd2/0x1a0
    vt_ioctl+0x507/0x12a0
    tty_ioctl+0x355/0xc30
    do_vfs_ioctl+0xa3/0x5e0
    SyS_ioctl+0x79/0x90
    entry_SYSCALL_64_fastpath+0x13/0x94

 - i915 unpin_work workqueue:

    intel_unpin_work_fn+0x58/0x140 [i915]
    process_one_work+0x1f1/0x480
    worker_thread+0x48/0x4d0
    kthread+0x101/0x140

and this patch purely papers over the issue by adding a NULL pointer
check and a WARN_ON_ONCE() to avoid the oops that would then generally
make the machine unresponsive.

Other callers of i915_gem_object_to_ggtt() seem to also check for the
returned pointer being NULL and warn about it, so this clearly has
happened before in other places.

[ Reported it originally to the i915 developers on Jan 8, applying the
  ugly workaround on my own now after triggering the problem for the
  second time with no feedback.

  This is likely to be the same bug reported as

     https://bugs.freedesktop.org/show_bug.cgi?id=98829
     https://bugs.freedesktop.org/show_bug.cgi?id=99134

  which has a patch for the underlying problem, but it hasn't gotten to
  me, so I'm applying the workaround. ]

Cc: Daniel Vetter &lt;daniel.vetter@intel.com&gt;
Cc: Jani Nikula &lt;jani.nikula@linux.intel.com&gt;
Cc: Ville Syrjälä &lt;ville.syrjala@linux.intel.com&gt;
Cc: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
Cc: Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&gt;
Cc: Tvrtko Ursulin &lt;tvrtko.ursulin@intel.com&gt;
Cc: Imre Deak &lt;imre.deak@intel.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>Diffstat</a> (limited to 'include/trace/events/intel-sst.h')</div><table summary='diffstat' class='diffstat'>