<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/gpu, branch v4.19.92</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>drm/amdgpu: fix uninitialized variable pasid_mapping_needed</title>
<updated>2019-12-31T15:36:19+00:00</updated>
<author>
<name>Colin Ian King</name>
<email>colin.king@canonical.com</email>
</author>
<published>2019-10-03T21:52:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6032df37982ab948e6d2a41744deabef9181bec9'/>
<id>6032df37982ab948e6d2a41744deabef9181bec9</id>
<content type='text'>
[ Upstream commit 17cf678a33c6196a3df4531fe5aec91384c9eeb5 ]

The boolean variable pasid_mapping_needed is not initialized and
there are code paths that do not assign it any value before it is
is read later.  Fix this by initializing pasid_mapping_needed to
false.

Addresses-Coverity: ("Uninitialized scalar variable")
Fixes: 6817bf283b2b ("drm/amdgpu: grab the id mgr lock while accessing passid_mapping")
Reviewed-by: Christian König &lt;christian.koenig@amd.com&gt;
Signed-off-by: Colin Ian King &lt;colin.king@canonical.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 17cf678a33c6196a3df4531fe5aec91384c9eeb5 ]

The boolean variable pasid_mapping_needed is not initialized and
there are code paths that do not assign it any value before it is
is read later.  Fix this by initializing pasid_mapping_needed to
false.

Addresses-Coverity: ("Uninitialized scalar variable")
Fixes: 6817bf283b2b ("drm/amdgpu: grab the id mgr lock while accessing passid_mapping")
Reviewed-by: Christian König &lt;christian.koenig@amd.com&gt;
Signed-off-by: Colin Ian King &lt;colin.king@canonical.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/amdgpu: fix bad DMA from INTERRUPT_CNTL2</title>
<updated>2019-12-31T15:36:15+00:00</updated>
<author>
<name>Sam Bobroff</name>
<email>sbobroff@linux.ibm.com</email>
</author>
<published>2019-11-17T23:53:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9234c9254e22da026e351cd4b7028e216abbeef0'/>
<id>9234c9254e22da026e351cd4b7028e216abbeef0</id>
<content type='text'>
[ Upstream commit 3d0e3ce52ce3eb4b9de3caf9c38dbb5a4d3e13c3 ]

The INTERRUPT_CNTL2 register expects a valid DMA address, but is
currently set with a GPU MC address.  This can cause problems on
systems that detect the resulting DMA read from an invalid address
(found on a Power8 guest).

Instead, use the DMA address of the dummy page because it will always
be safe.

Fixes: 27ae10641e9c ("drm/amdgpu: add interupt handler implementation for si v3")
Signed-off-by: Sam Bobroff &lt;sbobroff@linux.ibm.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 3d0e3ce52ce3eb4b9de3caf9c38dbb5a4d3e13c3 ]

The INTERRUPT_CNTL2 register expects a valid DMA address, but is
currently set with a GPU MC address.  This can cause problems on
systems that detect the resulting DMA read from an invalid address
(found on a Power8 guest).

Instead, use the DMA address of the dummy page because it will always
be safe.

Fixes: 27ae10641e9c ("drm/amdgpu: add interupt handler implementation for si v3")
Signed-off-by: Sam Bobroff &lt;sbobroff@linux.ibm.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/amdgpu: fix potential double drop fence reference</title>
<updated>2019-12-31T15:35:49+00:00</updated>
<author>
<name>Pan Bian</name>
<email>bianpan2016@163.com</email>
</author>
<published>2019-11-06T09:14:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2c528fa3c40d16c61da38a9f4fa7a0ce71df4db3'/>
<id>2c528fa3c40d16c61da38a9f4fa7a0ce71df4db3</id>
<content type='text'>
[ Upstream commit 946ab8db6953535a3a88c957db8328beacdfed9d ]

The object fence is not set to NULL after its reference is dropped. As a
result, its reference may be dropped again if error occurs after that,
which may lead to a use after free bug. To avoid the issue, fence is
explicitly set to NULL after dropping its reference.

Acked-by: Christian König &lt;christian.koenig@amd.com&gt;
Signed-off-by: Pan Bian &lt;bianpan2016@163.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 946ab8db6953535a3a88c957db8328beacdfed9d ]

The object fence is not set to NULL after its reference is dropped. As a
result, its reference may be dropped again if error occurs after that,
which may lead to a use after free bug. To avoid the issue, fence is
explicitly set to NULL after dropping its reference.

Acked-by: Christian König &lt;christian.koenig@amd.com&gt;
Signed-off-by: Pan Bian &lt;bianpan2016@163.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/amdgpu: disallow direct upload save restore list from gfx driver</title>
<updated>2019-12-31T15:35:48+00:00</updated>
<author>
<name>Hawking Zhang</name>
<email>Hawking.Zhang@amd.com</email>
</author>
<published>2019-11-04T08:20:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7b3fe663da71273710fc8f7fa0c71515e96c6786'/>
<id>7b3fe663da71273710fc8f7fa0c71515e96c6786</id>
<content type='text'>
[ Upstream commit 58f46d4b65021083ef4b4d49c6e2c58e5783f626 ]

Direct uploading save/restore list via mmio register writes breaks the security
policy. Instead, the driver should pass s&amp;r list to psp.

For all the ASICs that use rlc v2_1 headers, the driver actually upload s&amp;r list
twice, in non-psp ucode front door loading phase and gfx pg initialization phase.
The latter is not allowed.

VG12 is the only exception where the driver still keeps legacy approach for S&amp;R
list uploading. In theory, this can be elimnated if we have valid srcntl ucode
for VG12.

Signed-off-by: Hawking Zhang &lt;Hawking.Zhang@amd.com&gt;
Reviewed-by: Candice Li &lt;Candice.Li@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 58f46d4b65021083ef4b4d49c6e2c58e5783f626 ]

Direct uploading save/restore list via mmio register writes breaks the security
policy. Instead, the driver should pass s&amp;r list to psp.

For all the ASICs that use rlc v2_1 headers, the driver actually upload s&amp;r list
twice, in non-psp ucode front door loading phase and gfx pg initialization phase.
The latter is not allowed.

VG12 is the only exception where the driver still keeps legacy approach for S&amp;R
list uploading. In theory, this can be elimnated if we have valid srcntl ucode
for VG12.

Signed-off-by: Hawking Zhang &lt;Hawking.Zhang@amd.com&gt;
Reviewed-by: Candice Li &lt;Candice.Li@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>gpu: host1x: Allocate gather copy for host1x</title>
<updated>2019-12-31T15:35:29+00:00</updated>
<author>
<name>Thierry Reding</name>
<email>treding@nvidia.com</email>
</author>
<published>2019-10-28T12:37:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9287cc6123d55a019f03eb2d84aab7a2a15ee1f6'/>
<id>9287cc6123d55a019f03eb2d84aab7a2a15ee1f6</id>
<content type='text'>
[ Upstream commit b78e70c04c149299bd210759d7c7af7c86b89ca8 ]

Currently when the gather buffers are copied, they are copied to a
buffer that is allocated for the host1x client that wants to execute the
command streams in the buffers. However, the gather buffers will be read
by the host1x device, which causes SMMU faults if the DMA API is backed
by an IOMMU.

Fix this by allocating the gather buffer copy for the host1x device,
which makes sure that it will be mapped into the host1x's IOVA space if
the DMA API is backed by an IOMMU.

Signed-off-by: Thierry Reding &lt;treding@nvidia.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit b78e70c04c149299bd210759d7c7af7c86b89ca8 ]

Currently when the gather buffers are copied, they are copied to a
buffer that is allocated for the host1x client that wants to execute the
command streams in the buffers. However, the gather buffers will be read
by the host1x device, which causes SMMU faults if the DMA API is backed
by an IOMMU.

Fix this by allocating the gather buffer copy for the host1x device,
which makes sure that it will be mapped into the host1x's IOVA space if
the DMA API is backed by an IOMMU.

Signed-off-by: Thierry Reding &lt;treding@nvidia.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/tegra: sor: Use correct SOR index on Tegra210</title>
<updated>2019-12-31T15:35:27+00:00</updated>
<author>
<name>Thierry Reding</name>
<email>treding@nvidia.com</email>
</author>
<published>2019-07-24T15:06:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=16015bd930d6f27313a151a6bff42549ff91c699'/>
<id>16015bd930d6f27313a151a6bff42549ff91c699</id>
<content type='text'>
[ Upstream commit 24e64f86da40e68c5f58af08796110f147b12193 ]

The device tree bindings for the Tegra210 SOR don't require the
controller instance to be defined, since the instance can be derived
from the compatible string. The index is never used on Tegra210, so we
got away with it not getting set. However, subsequent patches will
change that, so make sure the proper index is used.

Signed-off-by: Thierry Reding &lt;treding@nvidia.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 24e64f86da40e68c5f58af08796110f147b12193 ]

The device tree bindings for the Tegra210 SOR don't require the
controller instance to be defined, since the instance can be derived
from the compatible string. The index is never used on Tegra210, so we
got away with it not getting set. However, subsequent patches will
change that, so make sure the proper index is used.

Signed-off-by: Thierry Reding &lt;treding@nvidia.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/gma500: fix memory disclosures due to uninitialized bytes</title>
<updated>2019-12-31T15:35:22+00:00</updated>
<author>
<name>Kangjie Lu</name>
<email>kjlu@umn.edu</email>
</author>
<published>2019-10-18T04:41:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7a284055e4c4d2b45955532252f8e63cc41aa2e0'/>
<id>7a284055e4c4d2b45955532252f8e63cc41aa2e0</id>
<content type='text'>
[ Upstream commit ec3b7b6eb8c90b52f61adff11b6db7a8db34de19 ]

"clock" may be copied to "best_clock". Initializing best_clock
is not sufficient. The fix initializes clock as well to avoid
memory disclosures and informaiton leaks.

Signed-off-by: Kangjie Lu &lt;kjlu@umn.edu&gt;
Signed-off-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20191018044150.1899-1-kjlu@umn.edu
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit ec3b7b6eb8c90b52f61adff11b6db7a8db34de19 ]

"clock" may be copied to "best_clock". Initializing best_clock
is not sufficient. The fix initializes clock as well to avoid
memory disclosures and informaiton leaks.

Signed-off-by: Kangjie Lu &lt;kjlu@umn.edu&gt;
Signed-off-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20191018044150.1899-1-kjlu@umn.edu
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/bridge: dw-hdmi: Restore audio when setting a mode</title>
<updated>2019-12-31T15:35:14+00:00</updated>
<author>
<name>Daniel Kurtz</name>
<email>djkurtz@chromium.org</email>
</author>
<published>2019-10-08T10:21:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=327e41607bd197fea43bfb0001b158210e89fc08'/>
<id>327e41607bd197fea43bfb0001b158210e89fc08</id>
<content type='text'>
[ Upstream commit fadfee3f9d8f114435a8a3e9f83a227600d89de7 ]

When setting a new display mode, dw_hdmi_setup() calls
dw_hdmi_enable_video_path(), which disables all hdmi clocks, including
the audio clock.

We should only (re-)enable the audio clock if audio was already enabled
when setting the new mode.

Without this patch, on RK3288, there will be HDMI audio on some monitors
if i2s was played to headphone when the monitor was plugged.
ACER H277HU and ASUS PB278 are two of the monitors showing this issue.

Signed-off-by: Cheng-Yi Chiang &lt;cychiang@chromium.org&gt;
Signed-off-by: Daniel Kurtz &lt;djkurtz@chromium.org&gt;
Signed-off-by: Yakir Yang &lt;ykk@rock-chips.com&gt;
Reviewed-by: Neil Armstrong &lt;narmstrong@baylibre.com&gt;
Signed-off-by: Neil Armstrong &lt;narmstrong@baylibre.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20191008102145.55134-1-cychiang@chromium.org
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit fadfee3f9d8f114435a8a3e9f83a227600d89de7 ]

When setting a new display mode, dw_hdmi_setup() calls
dw_hdmi_enable_video_path(), which disables all hdmi clocks, including
the audio clock.

We should only (re-)enable the audio clock if audio was already enabled
when setting the new mode.

Without this patch, on RK3288, there will be HDMI audio on some monitors
if i2s was played to headphone when the monitor was plugged.
ACER H277HU and ASUS PB278 are two of the monitors showing this issue.

Signed-off-by: Cheng-Yi Chiang &lt;cychiang@chromium.org&gt;
Signed-off-by: Daniel Kurtz &lt;djkurtz@chromium.org&gt;
Signed-off-by: Yakir Yang &lt;ykk@rock-chips.com&gt;
Reviewed-by: Neil Armstrong &lt;narmstrong@baylibre.com&gt;
Signed-off-by: Neil Armstrong &lt;narmstrong@baylibre.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20191008102145.55134-1-cychiang@chromium.org
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/amd/display: Fix dongle_caps containing stale information.</title>
<updated>2019-12-31T15:35:10+00:00</updated>
<author>
<name>David Galiffi</name>
<email>david.galiffi@amd.com</email>
</author>
<published>2019-09-21T00:20:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=59fc1675b5731b6cb57ad668ab2022add0433d5d'/>
<id>59fc1675b5731b6cb57ad668ab2022add0433d5d</id>
<content type='text'>
[ Upstream commit dd998291dbe92106d8c4a7581c409b356928d711 ]

[WHY]

During detection:
function: get_active_converter_info populates link-&gt;dpcd_caps.dongle_caps
only when dpcd_rev &gt;= DPCD_REV_11 and DWN_STRM_PORTX_TYPE is
DOWN_STREAM_DETAILED_HDMI or DOWN_STREAM_DETAILED_DP_PLUS_PLUS.
Otherwise, it is not cleared, and stale information remains.

During mode validation:
function: dp_active_dongle_validate_timing reads
link-&gt;dpcd_caps.dongle_caps-&gt;dongle_type to determine the maximum
pixel clock to support. This information is now stale and no longer
valid.

[HOW]
dp_active_dongle_validate_timing should be using
link-&gt;dpcd_caps-&gt;dongle_type instead.

Signed-off-by: David Galiffi &lt;david.galiffi@amd.com&gt;
Reviewed-by: Jun Lei &lt;Jun.Lei@amd.com&gt;
Acked-by: Bhawanpreet Lakha &lt;Bhawanpreet.Lakha@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit dd998291dbe92106d8c4a7581c409b356928d711 ]

[WHY]

During detection:
function: get_active_converter_info populates link-&gt;dpcd_caps.dongle_caps
only when dpcd_rev &gt;= DPCD_REV_11 and DWN_STRM_PORTX_TYPE is
DOWN_STREAM_DETAILED_HDMI or DOWN_STREAM_DETAILED_DP_PLUS_PLUS.
Otherwise, it is not cleared, and stale information remains.

During mode validation:
function: dp_active_dongle_validate_timing reads
link-&gt;dpcd_caps.dongle_caps-&gt;dongle_type to determine the maximum
pixel clock to support. This information is now stale and no longer
valid.

[HOW]
dp_active_dongle_validate_timing should be using
link-&gt;dpcd_caps-&gt;dongle_type instead.

Signed-off-by: David Galiffi &lt;david.galiffi@amd.com&gt;
Reviewed-by: Jun Lei &lt;Jun.Lei@amd.com&gt;
Acked-by: Bhawanpreet Lakha &lt;Bhawanpreet.Lakha@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/drm_vblank: Change EINVAL by the correct errno</title>
<updated>2019-12-31T15:35:01+00:00</updated>
<author>
<name>Rodrigo Siqueira</name>
<email>rodrigosiqueiramelo@gmail.com</email>
</author>
<published>2019-10-02T14:05:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5d60d398148d00a6fc8f0e1844055be3441e1d01'/>
<id>5d60d398148d00a6fc8f0e1844055be3441e1d01</id>
<content type='text'>
[ Upstream commit aed6105b28b10613f16c0bfe97525fe5a23338df ]

For historical reasons, the function drm_wait_vblank_ioctl always return
-EINVAL if something gets wrong. This scenario limits the flexibility
for the userspace to make detailed verification of any problem and take
some action. In particular, the validation of “if (!dev-&gt;irq_enabled)”
in the drm_wait_vblank_ioctl is responsible for checking if the driver
support vblank or not. If the driver does not support VBlank, the
function drm_wait_vblank_ioctl returns EINVAL, which does not represent
the real issue; this patch changes this behavior by return EOPNOTSUPP.
Additionally, drm_crtc_get_sequence_ioctl and
drm_crtc_queue_sequence_ioctl, also returns EINVAL if vblank is not
supported; this patch also changes the return value to EOPNOTSUPP in
these functions. Lastly, these functions are invoked by libdrm, which is
used by many compositors; because of this, it is important to check if
this change breaks any compositor. In this sense, the following projects
were examined:

* Drm-hwcomposer
* Kwin
* Sway
* Wlroots
* Wayland
* Weston
* Mutter
* Xorg (67 different drivers)

For each repository the verification happened in three steps:

* Update the main branch
* Look for any occurrence of "drmCrtcQueueSequence",
  "drmCrtcGetSequence", and "drmWaitVBlank" with the command git grep -n
  "STRING".
* Look in the git history of the project with the command
git log -S&lt;STRING&gt;

None of the above projects validate the use of EINVAL when using
drmWaitVBlank(), which make safe, at least for these projects, to change
the return values. On the other hand, mesa and xserver project uses
drmCrtcQueueSequence() and drmCrtcGetSequence(); this change is harmless
for both projects.

Change since V5 (Pekka Paalanen):
 - Check if the change also affects Mutter

Change since V4 (Daniel):
 - Also return EOPNOTSUPP in drm_crtc_[get|queue]_sequence_ioctl

Change since V3:
 - Return EINVAL for _DRM_VBLANK_SIGNAL (Daniel)

Change since V2:
 Daniel Vetter and Chris Wilson
 - Replace ENOTTY by EOPNOTSUPP
 - Return EINVAL if the parameters are wrong

Cc: Keith Packard &lt;keithp@keithp.com&gt;
Cc: Maarten Lankhorst &lt;maarten.lankhorst@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: Daniel Vetter &lt;daniel@ffwll.ch&gt;
Cc: Pekka Paalanen &lt;pekka.paalanen@collabora.com&gt;
Signed-off-by: Rodrigo Siqueira &lt;rodrigosiqueiramelo@gmail.com&gt;
Reviewed-by: Daniel Vetter &lt;daniel@ffwll.ch&gt;
Acked-by: Pekka Paalanen &lt;pekka.paalanen@collabora.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20191002140516.adeyj3htylimmlmg@smtp.gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
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[ Upstream commit aed6105b28b10613f16c0bfe97525fe5a23338df ]

For historical reasons, the function drm_wait_vblank_ioctl always return
-EINVAL if something gets wrong. This scenario limits the flexibility
for the userspace to make detailed verification of any problem and take
some action. In particular, the validation of “if (!dev-&gt;irq_enabled)”
in the drm_wait_vblank_ioctl is responsible for checking if the driver
support vblank or not. If the driver does not support VBlank, the
function drm_wait_vblank_ioctl returns EINVAL, which does not represent
the real issue; this patch changes this behavior by return EOPNOTSUPP.
Additionally, drm_crtc_get_sequence_ioctl and
drm_crtc_queue_sequence_ioctl, also returns EINVAL if vblank is not
supported; this patch also changes the return value to EOPNOTSUPP in
these functions. Lastly, these functions are invoked by libdrm, which is
used by many compositors; because of this, it is important to check if
this change breaks any compositor. In this sense, the following projects
were examined:

* Drm-hwcomposer
* Kwin
* Sway
* Wlroots
* Wayland
* Weston
* Mutter
* Xorg (67 different drivers)

For each repository the verification happened in three steps:

* Update the main branch
* Look for any occurrence of "drmCrtcQueueSequence",
  "drmCrtcGetSequence", and "drmWaitVBlank" with the command git grep -n
  "STRING".
* Look in the git history of the project with the command
git log -S&lt;STRING&gt;

None of the above projects validate the use of EINVAL when using
drmWaitVBlank(), which make safe, at least for these projects, to change
the return values. On the other hand, mesa and xserver project uses
drmCrtcQueueSequence() and drmCrtcGetSequence(); this change is harmless
for both projects.

Change since V5 (Pekka Paalanen):
 - Check if the change also affects Mutter

Change since V4 (Daniel):
 - Also return EOPNOTSUPP in drm_crtc_[get|queue]_sequence_ioctl

Change since V3:
 - Return EINVAL for _DRM_VBLANK_SIGNAL (Daniel)

Change since V2:
 Daniel Vetter and Chris Wilson
 - Replace ENOTTY by EOPNOTSUPP
 - Return EINVAL if the parameters are wrong

Cc: Keith Packard &lt;keithp@keithp.com&gt;
Cc: Maarten Lankhorst &lt;maarten.lankhorst@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: Daniel Vetter &lt;daniel@ffwll.ch&gt;
Cc: Pekka Paalanen &lt;pekka.paalanen@collabora.com&gt;
Signed-off-by: Rodrigo Siqueira &lt;rodrigosiqueiramelo@gmail.com&gt;
Reviewed-by: Daniel Vetter &lt;daniel@ffwll.ch&gt;
Acked-by: Pekka Paalanen &lt;pekka.paalanen@collabora.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20191002140516.adeyj3htylimmlmg@smtp.gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
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