<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/linux.git/drivers, branch v4.18.11</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=v4.18.11</id>
<link rel='self' href='https://git.radix-linux.su/kernel/linux.git/atom?h=v4.18.11'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/'/>
<updated>2018-09-29T09:56:03+00:00</updated>
<entry>
<title>spi: Fix double IDR allocation with DT aliases</title>
<updated>2018-09-29T09:56:03+00:00</updated>
<author>
<name>Geert Uytterhoeven</name>
<email>geert+renesas@glider.be</email>
</author>
<published>2018-08-21T09:53:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=e5bd6aca70efa763752aadc033027018a2aa8670'/>
<id>urn:sha1:e5bd6aca70efa763752aadc033027018a2aa8670</id>
<content type='text'>
commit 04b2d03a75652bda989de1595048f0501dc0c0a0 upstream.

If the SPI bus number is provided by a DT alias, idr_alloc() is called
twice, leading to:

    WARNING: CPU: 1 PID: 1 at drivers/spi/spi.c:2179 spi_register_controller+0x11c/0x5d8
    couldn't get idr

Fix this by moving the handling of fixed SPI bus numbers up, before the
DT handling code fills in ctlr-&gt;bus_num.

Fixes: 1a4327fbf4554d5b ("spi: fix IDR collision on systems with both fixed and dynamic SPI bus numbers")
Signed-off-by: Geert Uytterhoeven &lt;geert+renesas@glider.be&gt;
Tested-by: Fabio Estevam &lt;fabio.estevam@nxp.com&gt;
Signed-off-by: Mark Brown &lt;broonie@kernel.org&gt;
Cc: Sudip Mukherjee &lt;sudipm.mukherjee@gmail.com&gt;
Cc: Kirill Kapranov &lt;kirill.kapranov@compulab.co.il&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>iw_cxgb4: only allow 1 flush on user qps</title>
<updated>2018-09-29T09:56:03+00:00</updated>
<author>
<name>Steve Wise</name>
<email>swise@opengridcomputing.com</email>
</author>
<published>2018-08-31T14:15:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=4fda8face67c15d9e9a016e552963bf72e7fde84'/>
<id>urn:sha1:4fda8face67c15d9e9a016e552963bf72e7fde84</id>
<content type='text'>
commit 308aa2b8f7b7db3332a7d41099fd37851fb793b2 upstream.

Once the qp has been flushed, it cannot be flushed again.  The user qp
flush logic wasn't enforcing it however.  The bug can cause
touch-after-free crashes like:

Unable to handle kernel paging request for data at address 0x000001ec
Faulting instruction address: 0xc008000016069100
Oops: Kernel access of bad area, sig: 11 [#1]
...
NIP [c008000016069100] flush_qp+0x80/0x480 [iw_cxgb4]
LR [c00800001606cd6c] c4iw_modify_qp+0x71c/0x11d0 [iw_cxgb4]
Call Trace:
[c00800001606cd6c] c4iw_modify_qp+0x71c/0x11d0 [iw_cxgb4]
[c00800001606e868] c4iw_ib_modify_qp+0x118/0x200 [iw_cxgb4]
[c0080000119eae80] ib_security_modify_qp+0xd0/0x3d0 [ib_core]
[c0080000119c4e24] ib_modify_qp+0xc4/0x2c0 [ib_core]
[c008000011df0284] iwcm_modify_qp_err+0x44/0x70 [iw_cm]
[c008000011df0fec] destroy_cm_id+0xcc/0x370 [iw_cm]
[c008000011ed4358] rdma_destroy_id+0x3c8/0x520 [rdma_cm]
[c0080000134b0540] ucma_close+0x90/0x1b0 [rdma_ucm]
[c000000000444da4] __fput+0xe4/0x2f0

So fix flush_qp() to only flush the wq once.

Cc: stable@vger.kernel.org
Signed-off-by: Steve Wise &lt;swise@opengridcomputing.com&gt;
Signed-off-by: Jason Gunthorpe &lt;jgg@mellanox.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;


</content>
</entry>
<entry>
<title>vmw_balloon: include asm/io.h</title>
<updated>2018-09-29T09:56:02+00:00</updated>
<author>
<name>Nadav Amit</name>
<email>namit@vmware.com</email>
</author>
<published>2018-09-13T20:18:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=61b5194808f405fbf901f7c8280333cad0ec9768'/>
<id>urn:sha1:61b5194808f405fbf901f7c8280333cad0ec9768</id>
<content type='text'>
commit a3b92ee6fc171d7c9d9b6b829b7fef169210440c upstream.

Fix a build error due to missing virt_to_phys()

Reported-by: kbuild test robot &lt;lkp@intel.com&gt;
Fixes: f0a1bf29d821b ("vmw_balloon: fix inflation with batching")
Cc: stable@vger.kernel.org
Cc: Xavier Deguillard &lt;xdeguillard@vmware.com&gt;
Signed-off-by: Nadav Amit &lt;namit@vmware.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>tty: vt_ioctl: fix potential Spectre v1</title>
<updated>2018-09-29T09:56:00+00:00</updated>
<author>
<name>Gustavo A. R. Silva</name>
<email>gustavo@embeddedor.com</email>
</author>
<published>2018-08-16T20:30:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=52ef74c21c277e50de771fc722d814a830b3036b'/>
<id>urn:sha1:52ef74c21c277e50de771fc722d814a830b3036b</id>
<content type='text'>
commit e97267cb4d1ee01ca0929638ec0fcbb0904f903d upstream.

vsa.console is indirectly controlled by user-space, hence leading to
a potential exploitation of the Spectre variant 1 vulnerability.

This issue was detected with the help of Smatch:

drivers/tty/vt/vt_ioctl.c:711 vt_ioctl() warn: potential spectre issue
'vc_cons' [r]

Fix this by sanitizing vsa.console before using it to index vc_cons

Notice that given that speculation windows are large, the policy is
to kill the speculation on the first load and not worry if it can be
completed with a dependent load/store [1].

[1] https://marc.info/?l=linux-kernel&amp;m=152449131114778&amp;w=2

Cc: stable@vger.kernel.org
Signed-off-by: Gustavo A. R. Silva &lt;gustavo@embeddedor.com&gt;
Reviewed-by: Alan Cox &lt;alan@linux.intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>drm/amdgpu: add new polaris pci id</title>
<updated>2018-09-29T09:56:00+00:00</updated>
<author>
<name>Alex Deucher</name>
<email>alexander.deucher@amd.com</email>
</author>
<published>2018-09-18T20:28:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=5a5338e45009de6834778c34a026f735d5caba04'/>
<id>urn:sha1:5a5338e45009de6834778c34a026f735d5caba04</id>
<content type='text'>
commit 30f3984ede683b98a4e8096e200df78bf0609b4f upstream.

Add new pci id.

Reviewed-by: Rex Zhu &lt;Rex.Zhu@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>drm: udl: Destroy framebuffer only if it was initialized</title>
<updated>2018-09-29T09:56:00+00:00</updated>
<author>
<name>Emil Lundmark</name>
<email>lndmrk@chromium.org</email>
</author>
<published>2018-05-28T14:27:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=4cd5d680d8154ee3a061f6b36f1a4df6efa2da6c'/>
<id>urn:sha1:4cd5d680d8154ee3a061f6b36f1a4df6efa2da6c</id>
<content type='text'>
commit fcb74da1eb8edd3a4ef9b9724f88ed709d684227 upstream.

This fixes a NULL pointer dereference that can happen if the UDL
driver is unloaded before the framebuffer is initialized. This can
happen e.g. if the USB device is unplugged right after it was plugged
in.

As explained by Stéphane Marchesin:

It happens when fbdev is disabled (which is the case for Chrome OS).
Even though intialization of the fbdev part is optional (it's done in
udlfb_create which is the callback for fb_probe()), the teardown isn't
optional (udl_driver_unload -&gt; udl_fbdev_cleanup -&gt;
udl_fbdev_destroy).

Note that udl_fbdev_cleanup *tries* to be conditional (you can see it
does if (!udl-&gt;fbdev)) but that doesn't work, because udl-&gt;fbdev is
always set during udl_fbdev_init.

Cc: stable@vger.kernel.org
Suggested-by: Sean Paul &lt;seanpaul@chromium.org&gt;
Reviewed-by: Sean Paul &lt;seanpaul@chromium.org&gt;
Acked-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Signed-off-by: Emil Lundmark &lt;lndmrk@chromium.org&gt;
Signed-off-by: Sean Paul &lt;seanpaul@chromium.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20180528142711.142466-1-lndmrk@chromium.org
Signed-off-by: Sean Paul &lt;seanpaul@chromium.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>drm/vc4: Fix the "no scaling" case on multi-planar YUV formats</title>
<updated>2018-09-29T09:56:00+00:00</updated>
<author>
<name>Boris Brezillon</name>
<email>boris.brezillon@bootlin.com</email>
</author>
<published>2018-07-25T12:29:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=934df3d13fc60d8987f0b3e4920785355edf53fa'/>
<id>urn:sha1:934df3d13fc60d8987f0b3e4920785355edf53fa</id>
<content type='text'>
commit 658d8cbd07dae22ccecf49399e18c609c4e85c53 upstream.

When there's no scaling requested -&gt;is_unity should be true no matter
the format.

Also, when no scaling is requested and we have a multi-planar YUV
format, we should leave -&gt;y_scaling[0] to VC4_SCALING_NONE and only
set -&gt;x_scaling[0] to VC4_SCALING_PPF.

Doing this fixes an hardly visible artifact (seen when using modetest
and a rather big overlay plane in YUV420).

Fixes: fc04023fafec ("drm/vc4: Add support for YUV planes.")
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Boris Brezillon &lt;boris.brezillon@bootlin.com&gt;
Reviewed-by: Eric Anholt &lt;eric@anholt.net&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20180725122907.13702-1-boris.brezillon@bootlin.com
Signed-off-by: Sean Paul &lt;seanpaul@chromium.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>drm/nouveau/drm/nouveau: Prevent handling ACPI HPD events too early</title>
<updated>2018-09-29T09:55:59+00:00</updated>
<author>
<name>Lyude Paul</name>
<email>lyude@redhat.com</email>
</author>
<published>2018-08-16T20:13:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=21fb862e0e3c3125dabbee740c3f0e9f95d669b9'/>
<id>urn:sha1:21fb862e0e3c3125dabbee740c3f0e9f95d669b9</id>
<content type='text'>
commit 79e765ad665da4b8aa7e9c878bd2fef837f6fea5 upstream.

On most systems with ACPI hotplugging support, it seems that we always
receive a hotplug event once we re-enable EC interrupts even if the GPU
hasn't even been resumed yet.

This can cause problems since even though we schedule hpd_work to handle
connector reprobing for us, hpd_work synchronizes on
pm_runtime_get_sync() to wait until the device is ready to perform
reprobing. Since runtime suspend/resume callbacks are disabled before
the PM core calls -&gt;suspend(), any calls to pm_runtime_get_sync() during
this period will grab a runtime PM ref and return immediately with
-EACCES. Because we schedule hpd_work from our ACPI HPD handler, and
hpd_work synchronizes on pm_runtime_get_sync(), this causes us to launch
a connector reprobe immediately even if the GPU isn't actually resumed
just yet. This causes various warnings in dmesg and occasionally, also
prevents some displays connected to the dedicated GPU from coming back
up after suspend. Example:

usb 1-4: USB disconnect, device number 14
usb 1-4.1: USB disconnect, device number 15
WARNING: CPU: 0 PID: 838 at drivers/gpu/drm/nouveau/include/nvkm/subdev/i2c.h:170 nouveau_dp_detect+0x17e/0x370 [nouveau]
CPU: 0 PID: 838 Comm: kworker/0:6 Not tainted 4.17.14-201.Lyude.bz1477182.V3.fc28.x86_64 #1
Hardware name: LENOVO 20EQS64N00/20EQS64N00, BIOS N1EET77W (1.50 ) 03/28/2018
Workqueue: events nouveau_display_hpd_work [nouveau]
RIP: 0010:nouveau_dp_detect+0x17e/0x370 [nouveau]
RSP: 0018:ffffa15143933cf0 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff8cb4f656c400 RCX: 0000000000000000
RDX: ffffa1514500e4e4 RSI: ffffa1514500e4e4 RDI: 0000000001009002
RBP: ffff8cb4f4a8a800 R08: ffffa15143933cfd R09: ffffa15143933cfc
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8cb4fb57a000
R13: ffff8cb4fb57a000 R14: ffff8cb4f4a8f800 R15: ffff8cb4f656c418
FS:  0000000000000000(0000) GS:ffff8cb51f400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f78ec938000 CR3: 000000073720a003 CR4: 00000000003606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ? _cond_resched+0x15/0x30
 nouveau_connector_detect+0x2ce/0x520 [nouveau]
 ? _cond_resched+0x15/0x30
 ? ww_mutex_lock+0x12/0x40
 drm_helper_probe_detect_ctx+0x8b/0xe0 [drm_kms_helper]
 drm_helper_hpd_irq_event+0xa8/0x120 [drm_kms_helper]
 nouveau_display_hpd_work+0x2a/0x60 [nouveau]
 process_one_work+0x187/0x340
 worker_thread+0x2e/0x380
 ? pwq_unbound_release_workfn+0xd0/0xd0
 kthread+0x112/0x130
 ? kthread_create_worker_on_cpu+0x70/0x70
 ret_from_fork+0x35/0x40
Code: 4c 8d 44 24 0d b9 00 05 00 00 48 89 ef ba 09 00 00 00 be 01 00 00 00 e8 e1 09 f8 ff 85 c0 0f 85 b2 01 00 00 80 7c 24 0c 03 74 02 &lt;0f&gt; 0b 48 89 ef e8 b8 07 f8 ff f6 05 51 1b c8 ff 02 0f 84 72 ff
---[ end trace 55d811b38fc8e71a ]---

So, to fix this we attempt to grab a runtime PM reference in the ACPI
handler itself asynchronously. If the GPU is already awake (it will have
normal hotplugging at this point) or runtime PM callbacks are currently
disabled on the device, we drop our reference without updating the
autosuspend delay. We only schedule connector reprobes when we
successfully managed to queue up a resume request with our asynchronous
PM ref.

This also has the added benefit of preventing redundant connector
reprobes from ACPI while the GPU is runtime resumed!

Signed-off-by: Lyude Paul &lt;lyude@redhat.com&gt;
Cc: stable@vger.kernel.org
Cc: Karol Herbst &lt;kherbst@redhat.com&gt;
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1477182#c41
Signed-off-by: Lyude Paul &lt;lyude@redhat.com&gt;
Signed-off-by: Ben Skeggs &lt;bskeggs@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>drm/nouveau/drm/nouveau: Use pm_runtime_get_noresume() in connector_detect()</title>
<updated>2018-09-29T09:55:59+00:00</updated>
<author>
<name>Lyude Paul</name>
<email>lyude@redhat.com</email>
</author>
<published>2018-08-15T19:00:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=99aa61fb35ed40f5ae023549e50c3279e219de61'/>
<id>urn:sha1:99aa61fb35ed40f5ae023549e50c3279e219de61</id>
<content type='text'>
commit 6833fb1ec120bf078e1a527c573a09d4de286224 upstream.

It's true we can't resume the device from poll workers in
nouveau_connector_detect(). We can however, prevent the autosuspend
timer from elapsing immediately if it hasn't already without risking any
sort of deadlock with the runtime suspend/resume operations. So do that
instead of entirely avoiding grabbing a power reference.

Signed-off-by: Lyude Paul &lt;lyude@redhat.com&gt;
Reviewed-by: Karol Herbst &lt;kherbst@redhat.com&gt;
Acked-by: Daniel Vetter &lt;daniel@ffwll.ch&gt;
Cc: stable@vger.kernel.org
Cc: Lukas Wunner &lt;lukas@wunner.de&gt;
Signed-off-by: Ben Skeggs &lt;bskeggs@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>drm/nouveau/drm/nouveau: Fix deadlock with fb_helper with async RPM requests</title>
<updated>2018-09-29T09:55:59+00:00</updated>
<author>
<name>Lyude Paul</name>
<email>lyude@redhat.com</email>
</author>
<published>2018-08-15T19:00:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=9c7443a7aa646327acbaa02d16e7f7858e4e886c'/>
<id>urn:sha1:9c7443a7aa646327acbaa02d16e7f7858e4e886c</id>
<content type='text'>
commit 7fec8f5379fb6eddabc0aaef6d2304c366808f97 upstream.

Currently, nouveau uses the generic drm_fb_helper_output_poll_changed()
function provided by DRM as it's output_poll_changed callback.
Unfortunately however, this function doesn't grab runtime PM references
early enough and even if it did-we can't block waiting for the device to
resume in output_poll_changed() since it's very likely that we'll need
to grab the fb_helper lock at some point during the runtime resume
process. This currently results in deadlocking like so:

[  246.669625] INFO: task kworker/4:0:37 blocked for more than 120 seconds.
[  246.673398]       Not tainted 4.18.0-rc5Lyude-Test+ #2
[  246.675271] "echo 0 &gt; /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[  246.676527] kworker/4:0     D    0    37      2 0x80000000
[  246.677580] Workqueue: events output_poll_execute [drm_kms_helper]
[  246.678704] Call Trace:
[  246.679753]  __schedule+0x322/0xaf0
[  246.680916]  schedule+0x33/0x90
[  246.681924]  schedule_preempt_disabled+0x15/0x20
[  246.683023]  __mutex_lock+0x569/0x9a0
[  246.684035]  ? kobject_uevent_env+0x117/0x7b0
[  246.685132]  ? drm_fb_helper_hotplug_event.part.28+0x20/0xb0 [drm_kms_helper]
[  246.686179]  mutex_lock_nested+0x1b/0x20
[  246.687278]  ? mutex_lock_nested+0x1b/0x20
[  246.688307]  drm_fb_helper_hotplug_event.part.28+0x20/0xb0 [drm_kms_helper]
[  246.689420]  drm_fb_helper_output_poll_changed+0x23/0x30 [drm_kms_helper]
[  246.690462]  drm_kms_helper_hotplug_event+0x2a/0x30 [drm_kms_helper]
[  246.691570]  output_poll_execute+0x198/0x1c0 [drm_kms_helper]
[  246.692611]  process_one_work+0x231/0x620
[  246.693725]  worker_thread+0x214/0x3a0
[  246.694756]  kthread+0x12b/0x150
[  246.695856]  ? wq_pool_ids_show+0x140/0x140
[  246.696888]  ? kthread_create_worker_on_cpu+0x70/0x70
[  246.697998]  ret_from_fork+0x3a/0x50
[  246.699034] INFO: task kworker/0:1:60 blocked for more than 120 seconds.
[  246.700153]       Not tainted 4.18.0-rc5Lyude-Test+ #2
[  246.701182] "echo 0 &gt; /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[  246.702278] kworker/0:1     D    0    60      2 0x80000000
[  246.703293] Workqueue: pm pm_runtime_work
[  246.704393] Call Trace:
[  246.705403]  __schedule+0x322/0xaf0
[  246.706439]  ? wait_for_completion+0x104/0x190
[  246.707393]  schedule+0x33/0x90
[  246.708375]  schedule_timeout+0x3a5/0x590
[  246.709289]  ? mark_held_locks+0x58/0x80
[  246.710208]  ? _raw_spin_unlock_irq+0x2c/0x40
[  246.711222]  ? wait_for_completion+0x104/0x190
[  246.712134]  ? trace_hardirqs_on_caller+0xf4/0x190
[  246.713094]  ? wait_for_completion+0x104/0x190
[  246.713964]  wait_for_completion+0x12c/0x190
[  246.714895]  ? wake_up_q+0x80/0x80
[  246.715727]  ? get_work_pool+0x90/0x90
[  246.716649]  flush_work+0x1c9/0x280
[  246.717483]  ? flush_workqueue_prep_pwqs+0x1b0/0x1b0
[  246.718442]  __cancel_work_timer+0x146/0x1d0
[  246.719247]  cancel_delayed_work_sync+0x13/0x20
[  246.720043]  drm_kms_helper_poll_disable+0x1f/0x30 [drm_kms_helper]
[  246.721123]  nouveau_pmops_runtime_suspend+0x3d/0xb0 [nouveau]
[  246.721897]  pci_pm_runtime_suspend+0x6b/0x190
[  246.722825]  ? pci_has_legacy_pm_support+0x70/0x70
[  246.723737]  __rpm_callback+0x7a/0x1d0
[  246.724721]  ? pci_has_legacy_pm_support+0x70/0x70
[  246.725607]  rpm_callback+0x24/0x80
[  246.726553]  ? pci_has_legacy_pm_support+0x70/0x70
[  246.727376]  rpm_suspend+0x142/0x6b0
[  246.728185]  pm_runtime_work+0x97/0xc0
[  246.728938]  process_one_work+0x231/0x620
[  246.729796]  worker_thread+0x44/0x3a0
[  246.730614]  kthread+0x12b/0x150
[  246.731395]  ? wq_pool_ids_show+0x140/0x140
[  246.732202]  ? kthread_create_worker_on_cpu+0x70/0x70
[  246.732878]  ret_from_fork+0x3a/0x50
[  246.733768] INFO: task kworker/4:2:422 blocked for more than 120 seconds.
[  246.734587]       Not tainted 4.18.0-rc5Lyude-Test+ #2
[  246.735393] "echo 0 &gt; /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[  246.736113] kworker/4:2     D    0   422      2 0x80000080
[  246.736789] Workqueue: events_long drm_dp_mst_link_probe_work [drm_kms_helper]
[  246.737665] Call Trace:
[  246.738490]  __schedule+0x322/0xaf0
[  246.739250]  schedule+0x33/0x90
[  246.739908]  rpm_resume+0x19c/0x850
[  246.740750]  ? finish_wait+0x90/0x90
[  246.741541]  __pm_runtime_resume+0x4e/0x90
[  246.742370]  nv50_disp_atomic_commit+0x31/0x210 [nouveau]
[  246.743124]  drm_atomic_commit+0x4a/0x50 [drm]
[  246.743775]  restore_fbdev_mode_atomic+0x1c8/0x240 [drm_kms_helper]
[  246.744603]  restore_fbdev_mode+0x31/0x140 [drm_kms_helper]
[  246.745373]  drm_fb_helper_restore_fbdev_mode_unlocked+0x54/0xb0 [drm_kms_helper]
[  246.746220]  drm_fb_helper_set_par+0x2d/0x50 [drm_kms_helper]
[  246.746884]  drm_fb_helper_hotplug_event.part.28+0x96/0xb0 [drm_kms_helper]
[  246.747675]  drm_fb_helper_output_poll_changed+0x23/0x30 [drm_kms_helper]
[  246.748544]  drm_kms_helper_hotplug_event+0x2a/0x30 [drm_kms_helper]
[  246.749439]  nv50_mstm_hotplug+0x15/0x20 [nouveau]
[  246.750111]  drm_dp_send_link_address+0x177/0x1c0 [drm_kms_helper]
[  246.750764]  drm_dp_check_and_send_link_address+0xa8/0xd0 [drm_kms_helper]
[  246.751602]  drm_dp_mst_link_probe_work+0x51/0x90 [drm_kms_helper]
[  246.752314]  process_one_work+0x231/0x620
[  246.752979]  worker_thread+0x44/0x3a0
[  246.753838]  kthread+0x12b/0x150
[  246.754619]  ? wq_pool_ids_show+0x140/0x140
[  246.755386]  ? kthread_create_worker_on_cpu+0x70/0x70
[  246.756162]  ret_from_fork+0x3a/0x50
[  246.756847]
           Showing all locks held in the system:
[  246.758261] 3 locks held by kworker/4:0/37:
[  246.759016]  #0: 00000000f8df4d2d ((wq_completion)"events"){+.+.}, at: process_one_work+0x1b3/0x620
[  246.759856]  #1: 00000000e6065461 ((work_completion)(&amp;(&amp;dev-&gt;mode_config.output_poll_work)-&gt;work)){+.+.}, at: process_one_work+0x1b3/0x620
[  246.760670]  #2: 00000000cb66735f (&amp;helper-&gt;lock){+.+.}, at: drm_fb_helper_hotplug_event.part.28+0x20/0xb0 [drm_kms_helper]
[  246.761516] 2 locks held by kworker/0:1/60:
[  246.762274]  #0: 00000000fff6be0f ((wq_completion)"pm"){+.+.}, at: process_one_work+0x1b3/0x620
[  246.762982]  #1: 000000005ab44fb4 ((work_completion)(&amp;dev-&gt;power.work)){+.+.}, at: process_one_work+0x1b3/0x620
[  246.763890] 1 lock held by khungtaskd/64:
[  246.764664]  #0: 000000008cb8b5c3 (rcu_read_lock){....}, at: debug_show_all_locks+0x23/0x185
[  246.765588] 5 locks held by kworker/4:2/422:
[  246.766440]  #0: 00000000232f0959 ((wq_completion)"events_long"){+.+.}, at: process_one_work+0x1b3/0x620
[  246.767390]  #1: 00000000bb59b134 ((work_completion)(&amp;mgr-&gt;work)){+.+.}, at: process_one_work+0x1b3/0x620
[  246.768154]  #2: 00000000cb66735f (&amp;helper-&gt;lock){+.+.}, at: drm_fb_helper_restore_fbdev_mode_unlocked+0x4c/0xb0 [drm_kms_helper]
[  246.768966]  #3: 000000004c8f0b6b (crtc_ww_class_acquire){+.+.}, at: restore_fbdev_mode_atomic+0x4b/0x240 [drm_kms_helper]
[  246.769921]  #4: 000000004c34a296 (crtc_ww_class_mutex){+.+.}, at: drm_modeset_backoff+0x8a/0x1b0 [drm]
[  246.770839] 1 lock held by dmesg/1038:
[  246.771739] 2 locks held by zsh/1172:
[  246.772650]  #0: 00000000836d0438 (&amp;tty-&gt;ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40
[  246.773680]  #1: 000000001f4f4d48 (&amp;ldata-&gt;atomic_read_lock){+.+.}, at: n_tty_read+0xc1/0x870

[  246.775522] =============================================

After trying dozens of different solutions, I found one very simple one
that should also have the benefit of preventing us from having to fight
locking for the rest of our lives. So, we work around these deadlocks by
deferring all fbcon hotplug events that happen after the runtime suspend
process starts until after the device is resumed again.

Changes since v7:
 - Fixup commit message - Daniel Vetter

Changes since v6:
 - Remove unused nouveau_fbcon_hotplugged_in_suspend() - Ilia

Changes since v5:
 - Come up with the (hopefully final) solution for solving this dumb
   problem, one that is a lot less likely to cause issues with locking in
   the future. This should work around all deadlock conditions with fbcon
   brought up thus far.

Changes since v4:
 - Add nouveau_fbcon_hotplugged_in_suspend() to workaround deadlock
   condition that Lukas described
 - Just move all of this out of drm_fb_helper. It seems that other DRM
   drivers have already figured out other workarounds for this. If other
   drivers do end up needing this in the future, we can just move this
   back into drm_fb_helper again.

Changes since v3:
- Actually check if fb_helper is NULL in both new helpers
- Actually check drm_fbdev_emulation in both new helpers
- Don't fire off a fb_helper hotplug unconditionally; only do it if
  the following conditions are true (as otherwise, calling this in the
  wrong spot will cause Bad Things to happen):
  - fb_helper hotplug handling was actually inhibited previously
  - fb_helper actually has a delayed hotplug pending
  - fb_helper is actually bound
  - fb_helper is actually initialized
- Add __must_check to drm_fb_helper_suspend_hotplug(). There's no
  situation where a driver would actually want to use this without
  checking the return value, so enforce that
- Rewrite and clarify the documentation for both helpers.
- Make sure to return true in the drm_fb_helper_suspend_hotplug() stub
  that's provided in drm_fb_helper.h when CONFIG_DRM_FBDEV_EMULATION
  isn't enabled
- Actually grab the toplevel fb_helper lock in
  drm_fb_helper_resume_hotplug(), since it's possible other activity
  (such as a hotplug) could be going on at the same time the driver
  calls drm_fb_helper_resume_hotplug(). We need this to check whether or
  not drm_fb_helper_hotplug_event() needs to be called anyway

Signed-off-by: Lyude Paul &lt;lyude@redhat.com&gt;
Reviewed-by: Karol Herbst &lt;kherbst@redhat.com&gt;
Acked-by: Daniel Vetter &lt;daniel@ffwll.ch&gt;
Cc: stable@vger.kernel.org
Cc: Lukas Wunner &lt;lukas@wunner.de&gt;
Signed-off-by: Ben Skeggs &lt;bskeggs@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
</feed>
