PCI/PM: Rename pci_wakeup_bus() to pci_resume_bus()

A "wakeup" is a signal from a device telling the system that the device or
the whole system should be awakened and made active. PCI devices are m

PCI/PM: Rename pci_wakeup_bus() to pci_resume_bus()

A "wakeup" is a signal from a device telling the system that the device or
the whole system should be awakened and made active. PCI devices are made
active by "resuming" them.

pci_wakeup_bus() is not involved with the wakeup signal; it *resumes*
devices on a bus (possibly in response to a wakeup signal, but that's at a
higher level).

Rename pci_wakeup_bus() to pci_resume_bus() to better reflect what it does.
No functional change intended.

[bhelgaas: commit log, reorder before removal of pci_wakeup_event()]
Link: https://lore.kernel.org/r/20201125090733.77782-2-mika.westerberg@linux.intel.com
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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vga_switcheroo: simplify the return expression of vga_switcheroo_runtime_resume

Simplify the return expression.

Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Signed-off-by: Daniel Vetter <

vga_switcheroo: simplify the return expression of vga_switcheroo_runtime_resume

Simplify the return expression.

Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20200921131110.93365-1-miaoqinglang@huawei.com

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vga_switcheroo: no need to check return value of debugfs_create functions

When calling debugfs functions, there is no need to ever check the
return value. The function can work or not, but the code

vga_switcheroo: no need to check return value of debugfs_create functions

When calling debugfs functions, there is no need to ever check the
return value. The function can work or not, but the code logic should
never do something different based on this.

Also, because there is no need to save the file dentry, remove the local
variable and just recursively delete the whole directory when shutting
down.

Cc: Lukas Wunner <lukas@wunner.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Sean Paul <sean@poorly.run>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20190613114455.GA13119@kroah.com

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vgaswitcheroo: call fbcon_remap_all directly

While at it, clean up the interface a bit and push the console locking
into fbcon.c.

v2: Remove now outdated comment (Lukas).

v3: Forgot to add static

vgaswitcheroo: call fbcon_remap_all directly

While at it, clean up the interface a bit and push the console locking
into fbcon.c.

v2: Remove now outdated comment (Lukas).

v3: Forgot to add static inline to the dummy function.

Acked-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Lukas Wunner <lukas@wunner.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Sean Paul <sean@poorly.run>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Yisheng Xie <ysxie@foxmail.com>
Cc: linux-fbdev@vger.kernel.org
Link: https://patchwork.freedesktop.org/patch/msgid/20190528090304.9388-30-daniel.vetter@ffwll.ch

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vga_switcheroo: Fix missing gpu_bound call at audio client registration

The commit 37a3a98ef601 ("ALSA: hda - Enable runtime PM only for
discrete GPU") added a new ops gpu_bound to be called when GP

vga_switcheroo: Fix missing gpu_bound call at audio client registration

The commit 37a3a98ef601 ("ALSA: hda - Enable runtime PM only for
discrete GPU") added a new ops gpu_bound to be called when GPU gets
bound. The patch overlooked, however, that vga_switcheroo_enable() is
called only once at GPU is bound. When an audio client is registered
after that point, it would miss the gpu_bound call. This leads to the
unexpected lack of runtime PM in HD-audio side.

For addressing that regression, just call gpu_bound callback manually
at vga_switcheroo_register_audio_client() when the GPU was already
bound.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=201615
Fixes: 37a3a98ef601 ("ALSA: hda - Enable runtime PM only for discrete GPU")
Cc: <stable@vger.kernel.org>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

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ALSA: hda - Enable runtime PM only for discrete GPU

The recent change of vga_switcheroo allowed the runtime PM for
HD-audio on AMD GPUs, but this also resulted in a regression. When
the HD-audio co

ALSA: hda - Enable runtime PM only for discrete GPU

The recent change of vga_switcheroo allowed the runtime PM for
HD-audio on AMD GPUs, but this also resulted in a regression. When
the HD-audio controller driver gets runtime-suspended, HD-audio link
is turned off, and the hotplug notification is ignored. This leads to
the inconsistent audio state (the connection isn't notified and ELD is
ignored).

The best fix would be to implement the proper ELD notification via the
audio component, but it's still not ready. As a quick workaround,
this patch adds the check of runtime_idle and allows the runtime
suspend only when the vga_switcheroo is bound with discrete GPU.
That is, a system with a single GPU and APU would be again without
runtime PM to keep the HD-audio link for the hotplug notification and
ELD read out.

Also, the codec->auto_runtime_pm flag is set only for the discrete GPU
at the time GPU gets bound via vga_switcheroo (i.e. only dGPU is
forcibly runtime-PM enabled), so that APU can still get the ELD
notification.

For identifying which GPU is bound, a new vga_switcheroo client
callback, gpu_bound, is implemented. The vga_switcheroo simply calls
this when GPU is bound, and tells whether it's dGPU or APU.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=200945
Fixes: 07f4f97d7b4b ("vga_switcheroo: Use device link for HDA controller")
Reported-by: Jian-Hong Pan <jian-hong@endlessm.com>
Tested-by: Jian-Hong Pan <jian-hong@endlessm.com>
Acked-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

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vga_switcheroo: set audio client id according to bound GPU id

On modern laptop, there are more and more platforms
have two GPUs, and each of them maybe have audio codec
for HDMP/DP output. For some

vga_switcheroo: set audio client id according to bound GPU id

On modern laptop, there are more and more platforms
have two GPUs, and each of them maybe have audio codec
for HDMP/DP output. For some dGPU which is no output,
audio codec usually is disabled.

In currect HDA audio driver, it will set all codec as
VGA_SWITCHEROO_DIS, the audio which is binded to UMA
will be suspended if user use debugfs to contorl power

In HDA driver side, it is difficult to know which GPU
the audio has binded to. So set the bound gpu pci dev
to vga_switcheroo.

if the audio client is not the third registration, audio
id will set in vga_switcheroo enable function. if the
audio client is the last registration when vga_switcheroo
_ready() get true, we should get audio client id from bound
GPU directly.

Signed-off-by: Jim Qu <Jim.Qu@amd.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

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vga_switcheroo: Let HDA autosuspend on mux change

When switching the display on muxed machines, we currently force the HDA
controller into runtime suspend on the previously used GPU and into
runtime

vga_switcheroo: Let HDA autosuspend on mux change

When switching the display on muxed machines, we currently force the HDA
controller into runtime suspend on the previously used GPU and into
runtime active state on the newly used GPU.

That's unnecessary if the GPU uses driver power control, we can just let
the audio device autosuspend or autoresume as it sees fit.

Cc: Dave Airlie <airlied@redhat.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Peter Wu <peter@lekensteyn.nl>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://patchwork.freedesktop.org/patch/msgid/098ed883460eb4976a899eac6f5192fefc877c0f.1520068884.git.lukas@wunner.de

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vga_switcheroo: Use device link for HDA controller

Back in 2013, runtime PM for GPUs with integrated HDA controller was
introduced with commits 0d69704ae348 ("gpu/vga_switcheroo: add driver
control

vga_switcheroo: Use device link for HDA controller

Back in 2013, runtime PM for GPUs with integrated HDA controller was
introduced with commits 0d69704ae348 ("gpu/vga_switcheroo: add driver
control power feature. (v3)") and 246efa4a072f ("snd/hda: add runtime
suspend/resume on optimus support (v4)").

Briefly, the idea was that the HDA controller is forced on and off in
unison with the GPU.

The original code is mostly still in place even though it was never a
100% perfect solution: E.g. on access to the HDA controller, the GPU
is powered up via vga_switcheroo_runtime_resume_hdmi_audio() but there
are no provisions to keep it resumed until access to the HDA controller
has ceased: The GPU autosuspends after 5 seconds, rendering the HDA
controller inaccessible.

Additionally, a kludge is required when hda_intel.c probes: It has to
check whether the GPU is powered down (check_hdmi_disabled()) and defer
probing if so.

However in the meantime (in v4.10) the driver core has gained a feature
called device links which promises to solve such issues in a clean way:
It allows us to declare a dependency from the HDA controller (consumer)
to the GPU (supplier). The PM core then automagically ensures that the
GPU is runtime resumed as long as the HDA controller's ->probe hook is
executed and whenever the HDA controller is accessed.

By default, the HDA controller has a dependency on its parent, a PCIe
Root Port. Adding a device link creates another dependency on its
sibling:

PCIe Root Port
^ ^
| |
| |
HDA ===> GPU

The device link is not only used for runtime PM, it also guarantees that
on system sleep, the HDA controller suspends before the GPU and resumes
after the GPU, and on system shutdown the HDA controller's ->shutdown
hook is executed before the one of the GPU. It is a complete solution.

Using this functionality is as simple as calling device_link_add(),
which results in a dmesg entry like this:

pci 0000:01:00.1: Linked as a consumer to 0000:01:00.0

The code for the GPU-governed audio power management can thus be removed
(except where it's still needed for legacy manual power control).

The device link is added in a PCI quirk rather than in hda_intel.c.
It is therefore legal for the GPU to runtime suspend to D3cold even if
the HDA controller is not bound to a driver or if CONFIG_SND_HDA_INTEL
is not enabled, for accesses to the HDA controller will cause the GPU to
wake up regardless if they're occurring outside of hda_intel.c (think
config space readout via sysfs).

Contrary to the previous implementation, the HDA controller's power
state is now self-governed, rather than GPU-governed, whereas the GPU's
power state is no longer fully self-governed. (The HDA controller needs
to runtime suspend before the GPU can.)

It is thus crucial that runtime PM is always activated on the HDA
controller even if CONFIG_SND_HDA_POWER_SAVE_DEFAULT is set to 0 (which
is the default), lest the GPU stays awake. This is achieved by setting
the auto_runtime_pm flag on every codec and the AZX_DCAPS_PM_RUNTIME
flag on the HDA controller.

A side effect is that power consumption might be reduced if the GPU is
in use but the HDA controller is not, because the HDA controller is now
allowed to go to D3hot. Before, it was forced to stay in D0 as long as
the GPU was in use. (There is no reduction in power consumption on my
Nvidia GK107, but there might be on other chips.)

The code paths for legacy manual power control are adjusted such that
runtime PM is disabled during power off, thereby preventing the PM core
from resuming the HDA controller.

Note that the device link is not only added on vga_switcheroo capable
systems, but for *any* GPU with integrated HDA controller. The idea is
that the HDA controller streams audio via connectors located on the GPU,
so the GPU needs to be on for the HDA controller to do anything useful.

This commit implicitly fixes an unbalanced runtime PM ref upon unbind of
hda_intel.c: On ->probe, a runtime PM ref was previously released under
the condition "azx_has_pm_runtime(chip) || hda->use_vga_switcheroo", but
on ->remove a runtime PM ref was only acquired under the first of those
conditions. Thus, binding and unbinding the driver twice on a
vga_switcheroo capable system caused the runtime PM refcount to drop
below zero. The issue is resolved because the AZX_DCAPS_PM_RUNTIME flag
is now always set if use_vga_switcheroo is true.

For more information on device links please refer to:
https://www.kernel.org/doc/html/latest/driver-api/device_link.html
Documentation/driver-api/device_link.rst

Cc: Dave Airlie <airlied@redhat.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Peter Wu <peter@lekensteyn.nl>
Tested-by: Kai Heng Feng <kai.heng.feng@canonical.com> # AMD PowerXpress
Tested-by: Mike Lothian <mike@fireburn.co.uk> # AMD PowerXpress
Tested-by: Denis Lisov <dennis.lissov@gmail.com> # Nvidia Optimus
Tested-by: Peter Wu <peter@lekensteyn.nl> # Nvidia Optimus
Tested-by: Lukas Wunner <lukas@wunner.de> # MacBook Pro
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://patchwork.freedesktop.org/patch/msgid/51bd38360ff502a8c42b1ebf4405ee1d3f27118d.1520068884.git.lukas@wunner.de

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vga_switcheroo: Deduplicate power state tracking

If DRM drivers use runtime PM, they currently notify vga_switcheroo
whenever they ->runtime_suspend or ->runtime_resume to update
vga_switcheroo's in

vga_switcheroo: Deduplicate power state tracking

If DRM drivers use runtime PM, they currently notify vga_switcheroo
whenever they ->runtime_suspend or ->runtime_resume to update
vga_switcheroo's internal power state tracking.

That's essentially a duplication of a functionality performed by the
PM core as it already tracks the GPU's power state and vga_switcheroo
can always query it.

Introduce a new internal helper vga_switcheroo_pwr_state() which does
just that if runtime PM is used, or falls back to vga_switcheroo's
internal power state tracking if manual power control is used.
Drop a redundant power state check in set_audio_state() while at it.

This removes one of the two purposes of the notification mechanism
implemented by vga_switcheroo_set_dynamic_switch(). The other one is
power management of the audio device and we'll remove that next.

Cc: Dave Airlie <airlied@redhat.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Peter Wu <peter@lekensteyn.nl>
Tested-by: Kai Heng Feng <kai.heng.feng@canonical.com> # AMD PowerXpress
Tested-by: Mike Lothian <mike@fireburn.co.uk> # AMD PowerXpress
Tested-by: Denis Lisov <dennis.lissov@gmail.com> # Nvidia Optimus
Tested-by: Peter Wu <peter@lekensteyn.nl> # Nvidia Optimus
Tested-by: Lukas Wunner <lukas@wunner.de> # MacBook Pro
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://patchwork.freedesktop.org/patch/msgid/0aa49d735b988aa04524a8dc339582ace33f0f94.1520068884.git.lukas@wunner.de

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vga_switcheroo: Update PCI current_state on power change

When cutting power to a GPU and its integrated HDA controller, their
cached current_state should be updated to D3cold to reflect reality.

We

vga_switcheroo: Update PCI current_state on power change

When cutting power to a GPU and its integrated HDA controller, their
cached current_state should be updated to D3cold to reflect reality.

We currently rely on the DRM and HDA drivers to do that, however:

- The HDA driver updates the current_state in azx_vs_set_state(), which
will no longer be called with driver power control once we migrate to
device links. (It will still be called with manual power control.)

- If the HDA device is not bound, its current_state remains at D0 even
though the GPU driver may decide to go to D3cold.

- The DRM drivers update the current_state using pci_set_power_state()
which can't put the device into a deeper power state than D3hot if the
GPU is not deemed power-manageable by the platform (even though it
*is* power-manageable by some nonstandard means, such as a _DSM).

Centralize updating the current_state of the GPU and HDA controller in
vga_switcheroo's ->runtime_suspend hook to overcome these deficiencies.

The GPU and HDA controller are two functions of the same PCI device
(VGA class device on function 0 and audio device on function 1) and
no other PCI devices reside on the same bus since this is a PCIe
point-to-point link, so we can just walk the bus and update the
current_state of all devices.

On ->runtime_resume, the HDA controller is in D0uninitialized state.
Resume to D0active and then let it autosuspend as it sees fit.

Note that vga_switcheroo_init_domain_pm_ops() is not supposed to be
called by hybrid graphics laptops which power down the GPU via its root
port's _PR3 resources and consequently vga_switcheroo_runtime_suspend()
is not used. On those laptops, the root port is power-manageable by the
platform (instead of by a nonstandard means) and the current_state is
therefore updated by the PCI core through the following call chain:

pci_set_power_state()
__pci_complete_power_transition()
pci_bus_set_current_state()

Resuming to D0active happens through:

pci_set_power_state()
__pci_start_power_transition()
pci_wakeup_bus()

Cc: Dave Airlie <airlied@redhat.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Peter Wu <peter@lekensteyn.nl>
Tested-by: Kai Heng Feng <kai.heng.feng@canonical.com> # AMD PowerXpress
Tested-by: Mike Lothian <mike@fireburn.co.uk> # AMD PowerXpress
Tested-by: Denis Lisov <dennis.lissov@gmail.com> # Nvidia Optimus
Tested-by: Peter Wu <peter@lekensteyn.nl> # Nvidia Optimus
Tested-by: Lukas Wunner <lukas@wunner.de> # MacBook Pro
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://patchwork.freedesktop.org/patch/msgid/8416958482c8c42d6f311ea5c1e5a65ccf21f5db.1520068884.git.lukas@wunner.de

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drivers:gpu: vga :vga_switcheroo.c : Fixed some coding style issues

Fixed the following style issues

drivers/gpu/vga/vga_switcheroo.c:98: WARNING: please, no space before tabs
drivers/gpu/vga/vga_s

drivers:gpu: vga :vga_switcheroo.c : Fixed some coding style issues

Fixed the following style issues

drivers/gpu/vga/vga_switcheroo.c:98: WARNING: please, no space before tabs
drivers/gpu/vga/vga_switcheroo.c:99: WARNING: please, no space before tabs
drivers/gpu/vga/vga_switcheroo.c:102: WARNING: please, no space before tabs
drivers/gpu/vga/vga_switcheroo.c:103: WARNING: please, no space before tabs
drivers/gpu/vga/vga_switcheroo.c:129: WARNING: please, no space before tabs
drivers/gpu/vga/vga_switcheroo.c:135: WARNING: please, no space before tabs
drivers/gpu/vga/vga_switcheroo.c:217: WARNING: line over 80 characters
drivers/gpu/vga/vga_switcheroo.c:218: WARNING: line over 80 characters
drivers/gpu/vga/vga_switcheroo.c:308: WARNING: please, no space before tabs
drivers/gpu/vga/vga_switcheroo.c:340: WARNING: line over 80 characters
drivers/gpu/vga/vga_switcheroo.c:1087: WARNING: Block comments use * on subsequent lines
drivers/gpu/vga/vga_switcheroo.c:1087: WARNING: Block comments use a trailing */ on a separate line

Signed-off-by: Joan Jani <igiann@hotmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/HE1PR1001MB1148F38207BC31C860FAF06DC9560@HE1PR1001MB1148.EURPRD10.PROD.OUTLOOK.COM

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vga_switcheroo: Sphinxify docs

Fix up formatting glitches remaining after the automatic rst conversion.

Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: L

vga_switcheroo: Sphinxify docs

Fix up formatting glitches remaining after the automatic rst conversion.

Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/3a369602ae35fdbf5e4a12f7e172088c89fa27bb.1468225027.git.lukas@wunner.de

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vga_switcheroo: Support deferred probing of audio clients

Daniel Vetter pointed out that vga_switcheroo_client_probe_defer() could
be needed by audio clients as well. To avoid mistakes when someone

vga_switcheroo: Support deferred probing of audio clients

Daniel Vetter pointed out that vga_switcheroo_client_probe_defer() could
be needed by audio clients as well. To avoid mistakes when someone adds
conditions for these in the future, constrain the single existing
condition to VGA clients by checking for PCI_BASE_CLASS_DISPLAY. This
encompasses both PCI_CLASS_DISPLAY_VGA as well as PCI_CLASS_DISPLAY_3D,
which is used by some Nvidia Optimus GPUs.

Any future checks for audio clients should then be constrained to
PCI_BASE_CLASS_MULTIMEDIA.

v6: Spun out from commit introducing vga_switcheroo_client_probe_defer()
to keep it a pure refactoring change. (Emil Velikov, Jani Nikula)

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Emil Velikov <emil.l.velikov@gmail.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/358d58490eb9dda5f270d844b0dce511a2a20828.1464685538.git.lukas@wunner.de

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vga_switcheroo: Add helper for deferred probing

So far we've got one condition when DRM drivers need to defer probing
on a dual GPU system and it's coded separately into each of the relevant
drivers

vga_switcheroo: Add helper for deferred probing

So far we've got one condition when DRM drivers need to defer probing
on a dual GPU system and it's coded separately into each of the relevant
drivers. As suggested by Daniel Vetter, deduplicate that code in the
drivers and move it to a new vga_switcheroo helper. This yields better
encapsulation of concepts and lets us add further checks in a central
place. (The existing check pertains to pre-retina MacBook Pros and an
additional check is expected to be needed for retinas.)

One might be tempted to check deferred probing conditions in
vga_switcheroo_register_client(), but this is usually called fairly late
during driver load. The GPU is fully brought up and ready for switching
at that point. On boot the ->probe hook is potentially called dozens of
times until it finally succeeds, and each time we'd repeat bringup and
teardown of the GPU, lengthening boot time considerably and cluttering
logfiles. A separate helper is therefore needed which can be called
right at the beginning of the ->probe hook.

Note that amdgpu currently does not call this helper as the AMD GPUs
built into MacBook Pros are only supported by radeon so far.

v2: This helper could eventually be used by audio clients as well,
so rephrase kerneldoc to refer to "client" instead of "GPU"
and move the single existing check in an if block specific
to PCI_CLASS_DISPLAY_VGA devices. Move documentation on
that check from kerneldoc to a comment. (Daniel Vetter)

v3: Mandate in kerneldoc that registration of client shall only
happen after calling this helper. (Daniel Vetter)

v4: Rebase on 412c8f7de011 ("drm/radeon: Return -EPROBE_DEFER when
amdkfd not loaded")

v5: Some Optimus GPUs use PCI_CLASS_DISPLAY_3D, make sure those are
matched as well. (Emil Velikov)

v6: The if-condition referring to PCI_BASE_CLASS_DISPLAY may be
considered a functional change. Move to a separate commit to
keep this a pure refactoring change. (Emil Velikov, Jani Nikula)

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/575885fd440c2b13c3f19ddf44360cfbbff35f50.1464685538.git.lukas@wunner.de

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vga_switcheroo: Add support for switching only the DDC

Originally by Seth Forshee <seth.forshee@canonical.com>, 2012-10-04:
During graphics driver initialization it's useful to be able to mux

vga_switcheroo: Add support for switching only the DDC

Originally by Seth Forshee <seth.forshee@canonical.com>, 2012-10-04:
During graphics driver initialization it's useful to be able to mux
only the DDC to the inactive client in order to read the EDID. Add
a switch_ddc callback to allow capable handlers to provide this
functionality, and add vga_switcheroo_switch_ddc() to allow DRM
to mux only the DDC.

Modified by Dave Airlie <airlied@gmail.com>, 2012-12-22:
I can't figure out why I didn't like this, but I rewrote this [...]
to lock/unlock the ddc lines [...]. I think I'd prefer something
like that otherwise the interface got really ugly.

Modified by Lukas Wunner <lukas@wunner.de>, 2015-04 - 2015-10:
Change semantics of ->switch_ddc handler callback to return previous
DDC owner. Original version tried to determine previous DDC owner
with find_active_client() but this fails if the inactive client
registers before the active client.

Don't lock vgasr_mutex in _lock_ddc() / _unlock_ddc(), it can cause
deadlocks because (a) during switch (with vgasr_mutex already held),
GPU is woken and probes its outputs, tries to re-acquire vgasr_mutex
to lock DDC lines; (b) Likewise during switch, GPU is suspended and
calls cancel_delayed_work_sync() to stop output polling, if poll
task is running at this moment we may wait forever for it to finish.

Instead, lock mux_hw_lock when unregistering the handler because
the only reason why we'd want to lock vgasr_mutex in _lock_ddc() /
_unlock_ddc() is to block the handler from disappearing while DDC
lines are switched.

Also acquire mux_hw_lock in stage2 to avoid race condition where
reading the EDID and switching happens simultaneously. Likewise on
MIGD / MDIS commands and on runtime suspend.

v2.1: Overhaul locking, squash commits (Daniel Vetter)

v2.2: Readability improvements (Thierry Reding)

v2.3: Overhaul locking once more

v2.4: Retain semantics of ->switchto handler callback to switch all
pins, including DDC (Daniel Vetter)

v5: Rename ddc_lock to mux_hw_lock: Since we acquire this both
when calling ->switch_ddc and ->switchto, it protects not just
access to the DDC lines but to the mux in general. This is in
line with the DRM convention to use low-level locks to avoid
concurrent hw access (e.g. i2c, dp_aux) which are often called
hw_lock (Daniel Vetter)

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=88861
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=61115
Tested-by: Lukas Wunner <lukas@wunner.de>
[MBP 9,1 2012 intel IVB + nvidia GK107 pre-retina 15"]
Cc: Seth Forshee <seth.forshee@canonical.com>
Cc: Dave Airlie <airlied@gmail.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/e81ae9722b84c5ed591805fee3ea6dbf5dc6c4b3.1452525860.git.lukas@wunner.de

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vga_switcheroo: Add handler flags infrastructure

Allow handlers to declare their capabilities and allow clients to
obtain that information. So far we have these use cases:

* If the handler is able

vga_switcheroo: Add handler flags infrastructure

Allow handlers to declare their capabilities and allow clients to
obtain that information. So far we have these use cases:

* If the handler is able to switch DDC separately, clients need to
probe EDID with drm_get_edid_switcheroo(). We should allow them
to detect a capable handler to ensure this function only gets
called when needed.

* Likewise if the handler is unable to switch AUX separately, the active
client needs to communicate link training parameters to the inactive
client, which may then skip the AUX handshake and set up its output
with these pre-calibrated values (DisplayPort specification v1.1a,
section 2.5.3.3). Clients need a way to recognize such a situation.

The flags for the radeon_atpx_handler and amdgpu_atpx_handler are
initially set to 0, this can later on be amended with
handler_flags |= VGA_SWITCHEROO_CAN_SWITCH_DDC;
when a ->switch_ddc callback is added.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=88861
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=61115
Tested-by: Lukas Wunner <lukas@wunner.de>
[MBP 9,1 2012 intel IVB + nvidia GK107 pre-retina 15"]
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/2b0d93ed6e511ca09e95e45e0b35627f330fabce.1452525860.git.lukas@wunner.de

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PM / Domains: add setter for dev.pm_domain

Adds a function that sets the pointer to dev_pm_domain in struct device
and that warns if the device has already finished probing. The reason
why we want t

PM / Domains: add setter for dev.pm_domain

Adds a function that sets the pointer to dev_pm_domain in struct device
and that warns if the device has already finished probing. The reason
why we want to enforce that is because in the general case that can
cause problems and also that we can simplify code quite a bit if we can
always assume that.

This patch also changes all current code that directly sets the
dev.pm_domain pointer.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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vga_switcheroo: Prettify documentation

Fix indentation of vga_switcheroo sections in gpu.tmpl.

Change section type of API documentation from "chapter" to "sect1"
so that the individual functions no

vga_switcheroo: Prettify documentation

Fix indentation of vga_switcheroo sections in gpu.tmpl.

Change section type of API documentation from "chapter" to "sect1"
so that the individual functions no longer clutter up the ToC.
Group together under a new "API" chapter.

Fix wording "heretoforth" -> "henceforth".

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

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vga_switcheroo: Drop client power state VGA_SWITCHEROO_INIT

hda_intel.c:azx_probe() defers initialization of an audio controller
on the discrete GPU if the GPU is powered off. The power state of the

vga_switcheroo: Drop client power state VGA_SWITCHEROO_INIT

hda_intel.c:azx_probe() defers initialization of an audio controller
on the discrete GPU if the GPU is powered off. The power state of the
GPU is determined by calling vga_switcheroo_get_client_state().

vga_switcheroo_get_client_state() returns VGA_SWITCHEROO_INIT if
vga_switcheroo is not enabled, i.e. if no second GPU or no handler
has registered.

This can go wrong in the following scenario:
- Driver for the integrated GPU is not loaded.
- Driver for the discrete GPU registers with vga_switcheroo, uses driver
power control to power down the GPU, handler cuts power to the GPU.
- Driver for the audio controller gets loaded after the GPU was powered
down, calls vga_switcheroo_get_client_state() which returns
VGA_SWITCHEROO_INIT instead of VGA_SWITCHEROO_OFF.
- Consequence: azx_probe() tries to initialize the audio controller even
though the GPU is powered down.

The power state VGA_SWITCHEROO_INIT was introduced by c8e9cf7bb240
("vga_switcheroo: Add a helper function to get the client state").
It is not apparent what its benefit might be. The idea seems to
be to initialize the audio controller even if the power state is
VGA_SWITCHEROO_OFF (were vga_switcheroo enabled), but as shown
above this can fail.

Drop VGA_SWITCHEROO_INIT to solve this.

Acked-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Dave Airlie <airlied@redhat.com>

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vga_switcheroo: Constify vga_switcheroo_handler

vga_switcheroo_client_ops has always been declared const since its
introduction with 26ec685ff9d9 ("vga_switcheroo: Introduce struct
vga_switcheroo_cl

vga_switcheroo: Constify vga_switcheroo_handler

vga_switcheroo_client_ops has always been declared const since its
introduction with 26ec685ff9d9 ("vga_switcheroo: Introduce struct
vga_switcheroo_client_ops").

Do so for vga_switcheroo_handler as well.

drivers/gpu/drm/amd/amdgpu/amdgpu.ko:
6 .rodata 00009888
- 19 .data 00001f00
+ 19 .data 00001ee0
drivers/gpu/drm/nouveau/nouveau.ko:
6 .rodata 000460b8
17 .data 00018fe0
drivers/gpu/drm/radeon/radeon.ko:
- 7 .rodata 00030944
+ 7 .rodata 00030964
- 21 .data 0000d6a0
+ 21 .data 0000d678
drivers/platform/x86/apple-gmux.ko:
- 7 .rodata 00000140
+ 7 .rodata 00000160
- 11 .data 000000e0
+ 11 .data 000000b8

Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Darren Hart <dvhart@linux.intel.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Christian König <christian.koenig@amd.com>.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

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vga_switcheroo: Use enum vga_switcheroo_client_id instead of int

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <dan

vga_switcheroo: Use enum vga_switcheroo_client_id instead of int

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

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vga_switcheroo: Use VGA_SWITCHEROO_UNKNOWN_ID instead of -1

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.v

vga_switcheroo: Use VGA_SWITCHEROO_UNKNOWN_ID instead of -1

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

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vga_switcheroo: Use enum vga_switcheroo_state instead of int

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Alex Deucher <alexander.deuch

vga_switcheroo: Use enum vga_switcheroo_state instead of int

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

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vga_switcheroo: Add missing locking

The following functions iterate over the client list, invoke client
callbacks or invoke handler callbacks without locking anything at all:

- Introduced by c8e9cf

vga_switcheroo: Add missing locking

The following functions iterate over the client list, invoke client
callbacks or invoke handler callbacks without locking anything at all:

- Introduced by c8e9cf7bb240 ("vga_switcheroo: Add a helper function to
get the client state"):
vga_switcheroo_get_client_state()

- Introduced by 0d69704ae348 ("gpu/vga_switcheroo: add driver control
power feature. (v3)"):
vga_switcheroo_set_dynamic_switch()
vga_switcheroo_runtime_suspend()
vga_switcheroo_runtime_resume()
vga_switcheroo_runtime_resume_hdmi_audio()

Refactor vga_switcheroo_runtime_resume_hdmi_audio() a bit to be able to
release vgasr_mutex immediately after iterating over the client list.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

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