<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/gpu, branch v5.4.176</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>drm/msm/hdmi: Fix missing put_device() call in msm_hdmi_get_phy</title>
<updated>2022-02-01T16:24:39+00:00</updated>
<author>
<name>Miaoqian Lin</name>
<email>linmq006@gmail.com</email>
</author>
<published>2022-01-07T08:50:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=51edc483af6c663a5373d50015c7b85347f27769'/>
<id>51edc483af6c663a5373d50015c7b85347f27769</id>
<content type='text'>
[ Upstream commit 774fe0cd838d1b1419d41ab4ea0613c80d4ecbd7 ]

The reference taken by 'of_find_device_by_node()' must be released when
not needed anymore.
Add the corresponding 'put_device()' in the error handling path.

Fixes: e00012b256d4 ("drm/msm/hdmi: Make HDMI core get its PHY")
Signed-off-by: Miaoqian Lin &lt;linmq006@gmail.com&gt;
Reviewed-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Link: https://lore.kernel.org/r/20220107085026.23831-1-linmq006@gmail.com
Signed-off-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&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 774fe0cd838d1b1419d41ab4ea0613c80d4ecbd7 ]

The reference taken by 'of_find_device_by_node()' must be released when
not needed anymore.
Add the corresponding 'put_device()' in the error handling path.

Fixes: e00012b256d4 ("drm/msm/hdmi: Make HDMI core get its PHY")
Signed-off-by: Miaoqian Lin &lt;linmq006@gmail.com&gt;
Reviewed-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Link: https://lore.kernel.org/r/20220107085026.23831-1-linmq006@gmail.com
Signed-off-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/msm/dsi: invalid parameter check in msm_dsi_phy_enable</title>
<updated>2022-02-01T16:24:38+00:00</updated>
<author>
<name>José Expósito</name>
<email>jose.exposito89@gmail.com</email>
</author>
<published>2022-01-16T18:18:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=581317b1f001b7509041544d7019b75571daa100'/>
<id>581317b1f001b7509041544d7019b75571daa100</id>
<content type='text'>
commit 5e761a2287234bc402ba7ef07129f5103bcd775c upstream.

The function performs a check on the "phy" input parameter, however, it
is used before the check.

Initialize the "dev" variable after the sanity check to avoid a possible
NULL pointer dereference.

Fixes: 5c8290284402b ("drm/msm/dsi: Split PHY drivers to separate files")
Addresses-Coverity-ID: 1493860 ("Null pointer dereference")
Signed-off-by: José Expósito &lt;jose.exposito89@gmail.com&gt;
Reviewed-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Link: https://lore.kernel.org/r/20220116181844.7400-1-jose.exposito89@gmail.com
Signed-off-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 5e761a2287234bc402ba7ef07129f5103bcd775c upstream.

The function performs a check on the "phy" input parameter, however, it
is used before the check.

Initialize the "dev" variable after the sanity check to avoid a possible
NULL pointer dereference.

Fixes: 5c8290284402b ("drm/msm/dsi: Split PHY drivers to separate files")
Addresses-Coverity-ID: 1493860 ("Null pointer dereference")
Signed-off-by: José Expósito &lt;jose.exposito89@gmail.com&gt;
Reviewed-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Link: https://lore.kernel.org/r/20220116181844.7400-1-jose.exposito89@gmail.com
Signed-off-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/msm/dsi: Fix missing put_device() call in dsi_get_phy</title>
<updated>2022-02-01T16:24:37+00:00</updated>
<author>
<name>Miaoqian Lin</name>
<email>linmq006@gmail.com</email>
</author>
<published>2021-12-30T07:09:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b3e3d584f0f19e4a25aca8b9fab4b3174283608b'/>
<id>b3e3d584f0f19e4a25aca8b9fab4b3174283608b</id>
<content type='text'>
commit c04c3148ca12227d92f91b355b4538cc333c9922 upstream.

If of_find_device_by_node() succeeds, dsi_get_phy() doesn't
a corresponding put_device(). Thus add put_device() to fix the exception
handling.

Fixes: ec31abf ("drm/msm/dsi: Separate PHY to another platform device")
Signed-off-by: Miaoqian Lin &lt;linmq006@gmail.com&gt;
Reviewed-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Link: https://lore.kernel.org/r/20211230070943.18116-1-linmq006@gmail.com
Signed-off-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit c04c3148ca12227d92f91b355b4538cc333c9922 upstream.

If of_find_device_by_node() succeeds, dsi_get_phy() doesn't
a corresponding put_device(). Thus add put_device() to fix the exception
handling.

Fixes: ec31abf ("drm/msm/dsi: Separate PHY to another platform device")
Signed-off-by: Miaoqian Lin &lt;linmq006@gmail.com&gt;
Reviewed-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Link: https://lore.kernel.org/r/20211230070943.18116-1-linmq006@gmail.com
Signed-off-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/msm: Fix wrong size calculation</title>
<updated>2022-02-01T16:24:37+00:00</updated>
<author>
<name>Xianting Tian</name>
<email>xianting.tian@linux.alibaba.com</email>
</author>
<published>2022-01-12T12:33:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4abd2a7735e1c0ee1c53cf99f34d3e5a2971bfd0'/>
<id>4abd2a7735e1c0ee1c53cf99f34d3e5a2971bfd0</id>
<content type='text'>
commit 0a727b459ee39bd4c5ced19d6024258ac87b6b2e upstream.

For example, memory-region in .dts as below,
	reg = &lt;0x0 0x50000000 0x0 0x20000000&gt;

We can get below values,
struct resource r;
r.start = 0x50000000;
r.end	= 0x6fffffff;

So the size should be:
size = r.end - r.start + 1 = 0x20000000

Signed-off-by: Xianting Tian &lt;xianting.tian@linux.alibaba.com&gt;
Fixes: 072f1f9168ed ("drm/msm: add support for "stolen" mem")
Reviewed-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Link: https://lore.kernel.org/r/20220112123334.749776-1-xianting.tian@linux.alibaba.com
Signed-off-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 0a727b459ee39bd4c5ced19d6024258ac87b6b2e upstream.

For example, memory-region in .dts as below,
	reg = &lt;0x0 0x50000000 0x0 0x20000000&gt;

We can get below values,
struct resource r;
r.start = 0x50000000;
r.end	= 0x6fffffff;

So the size should be:
size = r.end - r.start + 1 = 0x20000000

Signed-off-by: Xianting Tian &lt;xianting.tian@linux.alibaba.com&gt;
Fixes: 072f1f9168ed ("drm/msm: add support for "stolen" mem")
Reviewed-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Link: https://lore.kernel.org/r/20220112123334.749776-1-xianting.tian@linux.alibaba.com
Signed-off-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/etnaviv: relax submit size limits</title>
<updated>2022-02-01T16:24:34+00:00</updated>
<author>
<name>Lucas Stach</name>
<email>l.stach@pengutronix.de</email>
</author>
<published>2022-01-06T18:10:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5cbcd1f5a20a60d77237276b692daba0d440550f'/>
<id>5cbcd1f5a20a60d77237276b692daba0d440550f</id>
<content type='text'>
commit e3d26528e083e612314d4dcd713f3d5a26143ddc upstream.

While all userspace tried to limit commandstreams to 64K in size,
a bug in the Mesa driver lead to command streams of up to 128K
being submitted. Allow those to avoid breaking existing userspace.

Fixes: 6dfa2fab8ddd ("drm/etnaviv: limit submit sizes")
Cc: stable@vger.kernel.org
Signed-off-by: Lucas Stach &lt;l.stach@pengutronix.de&gt;
Reviewed-by: Christian Gmeiner &lt;christian.gmeiner@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit e3d26528e083e612314d4dcd713f3d5a26143ddc upstream.

While all userspace tried to limit commandstreams to 64K in size,
a bug in the Mesa driver lead to command streams of up to 128K
being submitted. Allow those to avoid breaking existing userspace.

Fixes: 6dfa2fab8ddd ("drm/etnaviv: limit submit sizes")
Cc: stable@vger.kernel.org
Signed-off-by: Lucas Stach &lt;l.stach@pengutronix.de&gt;
Reviewed-by: Christian Gmeiner &lt;christian.gmeiner@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/vmwgfx: Fix stale file descriptors on failed usercopy</title>
<updated>2022-01-29T09:25:11+00:00</updated>
<author>
<name>Mathias Krause</name>
<email>minipli@grsecurity.net</email>
</author>
<published>2022-01-27T08:34:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=84b1259fe36ae0915f3d6ddcea6377779de48b82'/>
<id>84b1259fe36ae0915f3d6ddcea6377779de48b82</id>
<content type='text'>
commit a0f90c8815706981c483a652a6aefca51a5e191c upstream.

A failing usercopy of the fence_rep object will lead to a stale entry in
the file descriptor table as put_unused_fd() won't release it. This
enables userland to refer to a dangling 'file' object through that still
valid file descriptor, leading to all kinds of use-after-free
exploitation scenarios.

Fix this by deferring the call to fd_install() until after the usercopy
has succeeded.

Fixes: c906965dee22 ("drm/vmwgfx: Add export fence to file descriptor support")
Signed-off-by: Mathias Krause &lt;minipli@grsecurity.net&gt;
Signed-off-by: Zack Rusin &lt;zackr@vmware.com&gt;
Signed-off-by: Dave Airlie &lt;airlied@redhat.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit a0f90c8815706981c483a652a6aefca51a5e191c upstream.

A failing usercopy of the fence_rep object will lead to a stale entry in
the file descriptor table as put_unused_fd() won't release it. This
enables userland to refer to a dangling 'file' object through that still
valid file descriptor, leading to all kinds of use-after-free
exploitation scenarios.

Fix this by deferring the call to fd_install() until after the usercopy
has succeeded.

Fixes: c906965dee22 ("drm/vmwgfx: Add export fence to file descriptor support")
Signed-off-by: Mathias Krause &lt;minipli@grsecurity.net&gt;
Signed-off-by: Zack Rusin &lt;zackr@vmware.com&gt;
Signed-off-by: Dave Airlie &lt;airlied@redhat.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/i915: Flush TLBs before releasing backing store</title>
<updated>2022-01-29T09:25:09+00:00</updated>
<author>
<name>Tvrtko Ursulin</name>
<email>tvrtko.ursulin@intel.com</email>
</author>
<published>2021-10-19T12:27:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1b5553c79d52f17e735cd924ff2178a2409e6d0b'/>
<id>1b5553c79d52f17e735cd924ff2178a2409e6d0b</id>
<content type='text'>
commit 7938d61591d33394a21bdd7797a245b65428f44c upstream.

We need to flush TLBs before releasing backing store otherwise userspace
is able to encounter stale entries if a) it is not declaring access to
certain buffers and b) it races with the backing store release from a
such undeclared execution already executing on the GPU in parallel.

The approach taken is to mark any buffer objects which were ever bound
to the GPU and to trigger a serialized TLB flush when their backing
store is released.

Alternatively the flushing could be done on VMA unbind, at which point
we would be able to ascertain whether there is potential a parallel GPU
execution (which could race), but essentially it boils down to paying
the cost of TLB flushes potentially needlessly at VMA unbind time (when
the backing store is not known to be going away so not needed for
safety), versus potentially needlessly at backing store relase time
(since we at that point cannot tell whether there is anything executing
on the GPU which uses that object).

Thereforce simplicity of implementation has been chosen for now with
scope to benchmark and refine later as required.

Signed-off-by: Tvrtko Ursulin &lt;tvrtko.ursulin@intel.com&gt;
Reported-by: Sushma Venkatesh Reddy &lt;sushma.venkatesh.reddy@intel.com&gt;
Reviewed-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Acked-by: Dave Airlie &lt;airlied@redhat.com&gt;
Cc: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Cc: Jon Bloomfield &lt;jon.bloomfield@intel.com&gt;
Cc: Joonas Lahtinen &lt;joonas.lahtinen@linux.intel.com&gt;
Cc: Jani Nikula &lt;jani.nikula@intel.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 7938d61591d33394a21bdd7797a245b65428f44c upstream.

We need to flush TLBs before releasing backing store otherwise userspace
is able to encounter stale entries if a) it is not declaring access to
certain buffers and b) it races with the backing store release from a
such undeclared execution already executing on the GPU in parallel.

The approach taken is to mark any buffer objects which were ever bound
to the GPU and to trigger a serialized TLB flush when their backing
store is released.

Alternatively the flushing could be done on VMA unbind, at which point
we would be able to ascertain whether there is potential a parallel GPU
execution (which could race), but essentially it boils down to paying
the cost of TLB flushes potentially needlessly at VMA unbind time (when
the backing store is not known to be going away so not needed for
safety), versus potentially needlessly at backing store relase time
(since we at that point cannot tell whether there is anything executing
on the GPU which uses that object).

Thereforce simplicity of implementation has been chosen for now with
scope to benchmark and refine later as required.

Signed-off-by: Tvrtko Ursulin &lt;tvrtko.ursulin@intel.com&gt;
Reported-by: Sushma Venkatesh Reddy &lt;sushma.venkatesh.reddy@intel.com&gt;
Reviewed-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Acked-by: Dave Airlie &lt;airlied@redhat.com&gt;
Cc: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
Cc: Jon Bloomfield &lt;jon.bloomfield@intel.com&gt;
Cc: Joonas Lahtinen &lt;joonas.lahtinen@linux.intel.com&gt;
Cc: Jani Nikula &lt;jani.nikula@intel.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/radeon: fix error handling in radeon_driver_open_kms</title>
<updated>2022-01-27T08:19:51+00:00</updated>
<author>
<name>Christian König</name>
<email>christian.koenig@amd.com</email>
</author>
<published>2022-01-17T09:31:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=227afbfe47b505a56e34f0fd8d288ce5bbab2032'/>
<id>227afbfe47b505a56e34f0fd8d288ce5bbab2032</id>
<content type='text'>
commit 4722f463896cc0ef1a6f1c3cb2e171e949831249 upstream.

The return value was never initialized so the cleanup code executed when
it isn't even necessary.

Just add proper error handling.

Fixes: ab50cb9df889 ("drm/radeon/radeon_kms: Fix a NULL pointer dereference in radeon_driver_open_kms()")
Signed-off-by: Christian König &lt;christian.koenig@amd.com&gt;
Tested-by: Jan Stancek &lt;jstancek@redhat.com&gt;
Tested-by: Borislav Petkov &lt;bp@suse.de&gt;
Reviewed-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 4722f463896cc0ef1a6f1c3cb2e171e949831249 upstream.

The return value was never initialized so the cleanup code executed when
it isn't even necessary.

Just add proper error handling.

Fixes: ab50cb9df889 ("drm/radeon/radeon_kms: Fix a NULL pointer dereference in radeon_driver_open_kms()")
Signed-off-by: Christian König &lt;christian.koenig@amd.com&gt;
Tested-by: Jan Stancek &lt;jstancek@redhat.com&gt;
Tested-by: Borislav Petkov &lt;bp@suse.de&gt;
Reviewed-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/bridge: analogix_dp: Make PSR-exit block less</title>
<updated>2022-01-27T08:19:50+00:00</updated>
<author>
<name>Brian Norris</name>
<email>briannorris@chromium.org</email>
</author>
<published>2021-11-03T20:52:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=db531b57cb506ddd6023d93ef68b49caae04fdcc'/>
<id>db531b57cb506ddd6023d93ef68b49caae04fdcc</id>
<content type='text'>
commit c4c6ef229593366ab593d4d424addc7025b54a76 upstream.

Prior to commit 6c836d965bad ("drm/rockchip: Use the helpers for PSR"),
"PSR exit" used non-blocking analogix_dp_send_psr_spd(). The refactor
started using the blocking variant, for a variety of reasons -- quoting
Sean Paul's potentially-faulty memory:

"""
 - To avoid racing a subsequent PSR entry (if exit takes a long time)
 - To avoid racing disable/modeset
 - We're not displaying new content while exiting PSR anyways, so there
   is minimal utility in allowing frames to be submitted
 - We're lying to userspace telling them frames are on the screen when
   we're just dropping them on the floor
"""

However, I'm finding that this blocking transition is causing upwards of
60+ ms of unneeded latency on PSR-exit, to the point that initial cursor
movements when leaving PSR are unbearably jumpy.

It turns out that we need to meet in the middle somewhere: Sean is right
that we were "lying to userspace" with a non-blocking PSR-exit, but the
new blocking behavior is also waiting too long:

According to the eDP specification, the sink device must support PSR
entry transitions from both state 4 (ACTIVE_RESYNC) and state 0
(INACTIVE). It also states that in ACTIVE_RESYNC, "the Sink device must
display the incoming active frames from the Source device with no
visible glitches and/or artifacts."

Thus, for our purposes, we only need to wait for ACTIVE_RESYNC before
moving on; we are ready to display video, and subsequent PSR-entry is
safe.

Tested on a Samsung Chromebook Plus (i.e., Rockchip RK3399 Gru Kevin),
where this saves about 60ms of latency, for PSR-exit that used to
take about 80ms.

Fixes: 6c836d965bad ("drm/rockchip: Use the helpers for PSR")
Cc: &lt;stable@vger.kernel.org&gt;
Cc: Zain Wang &lt;wzz@rock-chips.com&gt;
Cc: Tomasz Figa &lt;tfiga@chromium.org&gt;
Cc: Heiko Stuebner &lt;heiko@sntech.de&gt;
Cc: Sean Paul &lt;seanpaul@chromium.org&gt;
Signed-off-by: Brian Norris &lt;briannorris@chromium.org&gt;
Reviewed-by: Sean Paul &lt;seanpaul@chromium.org&gt;
Signed-off-by: Robert Foss &lt;robert.foss@linaro.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20211103135112.v3.1.I67612ea073c3306c71b46a87be894f79707082df@changeid
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit c4c6ef229593366ab593d4d424addc7025b54a76 upstream.

Prior to commit 6c836d965bad ("drm/rockchip: Use the helpers for PSR"),
"PSR exit" used non-blocking analogix_dp_send_psr_spd(). The refactor
started using the blocking variant, for a variety of reasons -- quoting
Sean Paul's potentially-faulty memory:

"""
 - To avoid racing a subsequent PSR entry (if exit takes a long time)
 - To avoid racing disable/modeset
 - We're not displaying new content while exiting PSR anyways, so there
   is minimal utility in allowing frames to be submitted
 - We're lying to userspace telling them frames are on the screen when
   we're just dropping them on the floor
"""

However, I'm finding that this blocking transition is causing upwards of
60+ ms of unneeded latency on PSR-exit, to the point that initial cursor
movements when leaving PSR are unbearably jumpy.

It turns out that we need to meet in the middle somewhere: Sean is right
that we were "lying to userspace" with a non-blocking PSR-exit, but the
new blocking behavior is also waiting too long:

According to the eDP specification, the sink device must support PSR
entry transitions from both state 4 (ACTIVE_RESYNC) and state 0
(INACTIVE). It also states that in ACTIVE_RESYNC, "the Sink device must
display the incoming active frames from the Source device with no
visible glitches and/or artifacts."

Thus, for our purposes, we only need to wait for ACTIVE_RESYNC before
moving on; we are ready to display video, and subsequent PSR-entry is
safe.

Tested on a Samsung Chromebook Plus (i.e., Rockchip RK3399 Gru Kevin),
where this saves about 60ms of latency, for PSR-exit that used to
take about 80ms.

Fixes: 6c836d965bad ("drm/rockchip: Use the helpers for PSR")
Cc: &lt;stable@vger.kernel.org&gt;
Cc: Zain Wang &lt;wzz@rock-chips.com&gt;
Cc: Tomasz Figa &lt;tfiga@chromium.org&gt;
Cc: Heiko Stuebner &lt;heiko@sntech.de&gt;
Cc: Sean Paul &lt;seanpaul@chromium.org&gt;
Signed-off-by: Brian Norris &lt;briannorris@chromium.org&gt;
Reviewed-by: Sean Paul &lt;seanpaul@chromium.org&gt;
Signed-off-by: Robert Foss &lt;robert.foss@linaro.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20211103135112.v3.1.I67612ea073c3306c71b46a87be894f79707082df@changeid
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/nouveau/kms/nv04: use vzalloc for nv04_display</title>
<updated>2022-01-27T08:19:50+00:00</updated>
<author>
<name>Ilia Mirkin</name>
<email>imirkin@alum.mit.edu</email>
</author>
<published>2021-03-07T17:48:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=17d492d39e17fa5a1d06a8c1ea5faf18f44e2884'/>
<id>17d492d39e17fa5a1d06a8c1ea5faf18f44e2884</id>
<content type='text'>
commit bd6e07e72f37f34535bec7eebc807e5fcfe37b43 upstream.

The struct is giant, and triggers an order-7 allocation (512K). There is
no reason for this to be kmalloc-type memory, so switch to vmalloc. This
should help loading nouveau on low-memory and/or long-running systems.

Reported-by: Nathan E. Egge &lt;unlord@xiph.org&gt;
Signed-off-by: Ilia Mirkin &lt;imirkin@alum.mit.edu&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Ben Skeggs &lt;bskeggs@redhat.com&gt;
Reviewed-by: Karol Herbst &lt;kherbst@redhat.com&gt;
Signed-off-by: Karol Herbst &lt;kherbst@redhat.com&gt;
Link: https://gitlab.freedesktop.org/drm/nouveau/-/merge_requests/10
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit bd6e07e72f37f34535bec7eebc807e5fcfe37b43 upstream.

The struct is giant, and triggers an order-7 allocation (512K). There is
no reason for this to be kmalloc-type memory, so switch to vmalloc. This
should help loading nouveau on low-memory and/or long-running systems.

Reported-by: Nathan E. Egge &lt;unlord@xiph.org&gt;
Signed-off-by: Ilia Mirkin &lt;imirkin@alum.mit.edu&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Ben Skeggs &lt;bskeggs@redhat.com&gt;
Reviewed-by: Karol Herbst &lt;kherbst@redhat.com&gt;
Signed-off-by: Karol Herbst &lt;kherbst@redhat.com&gt;
Link: https://gitlab.freedesktop.org/drm/nouveau/-/merge_requests/10
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
