linux-toradex.git/include/linux/vga_switcheroo.h, branch v4.4.40

vga_switcheroo: Drop client power state VGA_SWITCHEROO_INIT

2015-11-05T01:07:36+00:00

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 
Signed-off-by: Lukas Wunner 
Signed-off-by: Dave Airlie

vga_switcheroo: Constify vga_switcheroo_handler

2015-10-20T18:19:29+00:00

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 
Cc: Darren Hart 
Cc: Alex Deucher 
Signed-off-by: Lukas Wunner 
Reviewed-by: Christian König .
Signed-off-by: Daniel Vetter

vga_switcheroo: Use enum vga_switcheroo_client_id instead of int

2015-10-16T13:50:56+00:00

Signed-off-by: Lukas Wunner 
Reviewed-by: Alex Deucher 
Signed-off-by: Daniel Vetter

vga_switcheroo: Use VGA_SWITCHEROO_UNKNOWN_ID instead of -1

2015-10-16T13:50:56+00:00

Signed-off-by: Lukas Wunner 
Reviewed-by: Alex Deucher 
Signed-off-by: Daniel Vetter

vga_switcheroo: Use enum vga_switcheroo_state instead of int

2015-10-16T13:50:55+00:00

Signed-off-by: Lukas Wunner 
Reviewed-by: Jani Nikula 
Reviewed-by: Alex Deucher 
Signed-off-by: Daniel Vetter

vga_switcheroo: Set active attribute to false for audio clients

2015-09-24T18:14:25+00:00

The active attribute in struct vga_switcheroo_client denotes whether
the outputs are currently switched to this client. The attribute is
only meaningful for vga clients. It is never used for audio clients.

The function vga_switcheroo_register_audio_client() misuses this
attribute to store whether the audio device is fully initialized.
Most likely there was a misunderstanding about the meaning of
"active" when this was added.

Comment from Takashi's review:

"Not really.  The full initialization of audio was meant that the audio
is active indeed.  Admittedly, though, the active flag for each audio
client doesn't play any role because the audio always follows the gfx
state changes, and the value passed there doesn't reflect the actual
state due to the later change.  So, I agree with the removal of the
flag itself -- or let the audio active flag following the
corresponding gfx flag.  The latter will make the proc output more
consistent while the former is certainly more reduction of code."

Set the active attribute to false for audio clients. Remove the
active parameter from vga_switcheroo_register_audio_client() and
its sole caller, hda_intel.c:register_vga_switcheroo().

vga_switcheroo_register_audio_client() was introduced by 3e9e63dbd374
("vga_switcheroo: Add the support for audio clients"). Its use in
hda_intel.c was introduced by a82d51ed24bb ("ALSA: hda - Support
VGA-switcheroo").

v1.1: The changes above imply that in find_active_client() the call
to client_is_vga() is now superfluous. Drop it.

Cc: Takashi Iwai 
Signed-off-by: Lukas Wunner 
[danvet: Add Takashi's clarification to the commit message.]
Reviewed-by: Takashi Iwai 
Signed-off-by: Daniel Vetter

vga_switcheroo: Document _ALL_ the things!

2015-09-22T08:37:26+00:00

This adds an "Overview" DOC section plus two DOC sections for the modes
of use ("Manual switching and manual power control" and "Driver power
control").

Also included is kernel-doc for all public functions, structs and enums.

Signed-off-by: Lukas Wunner 
Signed-off-by: Daniel Vetter

vgaswitcheroo: add vga_switcheroo_fini_domain_pm_ops

2014-09-18T23:21:20+00:00

Drivers should call this on unload to unregister pmops.

Bug:
https://bugzilla.kernel.org/show_bug.cgi?id=84431

Reviewed-by: Ben Skeggs 
Signed-off-by: Alex Deucher 
Cc: stable@vger.kernel.org
Signed-off-by: Pali Rohár 
Cc: Ben Skeggs

gpu/vga_switcheroo: add driver control power feature. (v3)

2013-08-29T03:30:21+00:00

For optimus and powerxpress muxless we really want the GPU
driver deciding when to power up/down the GPU, not userspace.

This adds the ability for a driver to dynamically power up/down
the GPU and remove the switcheroo from controlling it, the
switcheroo reports the dynamic state to userspace also.

It also adds 2 power domains, one for machine where the power
switch is controlled outside the GPU D3 state, so the powerdown
ordering is done correctly, and the second for the hdmi audio
device to make sure it can resume for PCI config space accesses.

v1.1: fix build with switcheroo off

v2: add power domain support for radeon and v1 nvidia dsms
v2.1: fix typo in off case

v3: add audio power domain for hdmi audio + misc audio fixes

v4: use PCI_SLOT macro, drop power reference on hdmi audio resume
failure also.

Signed-off-by: Dave Airlie

vga_switcheroo: Add include guard

2012-06-21T08:32:16+00:00

Guard vga_switcheroo.h against multiple inclusion.

Signed-off-by: Ozan Çağlayan 
Signed-off-by: Dave Airlie