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
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
Pull more power management and ACPI updates from Rafael Wysocki:
"This includes fixes on top of the previous batch of PM+ACPI updates
and some new material as well.
From the new material perspective the most significant are the driver
core changes that should allow USB devices to stay suspended over
system suspend/resume cycles if they have been runtime-suspended
already beforehand. Apart from that, ACPICA is updated to upstream
revision 20160108 (cosmetic mostly, but including one fixup on top of
the previous ACPICA update) and there are some devfreq updates the
didn't make it before (due to timing).
A few recent regressions are fixed, most importantly in the cpuidle
menu governor and in the ACPI backlight driver and some x86 platform
drivers depending on it.
Some more bugs are fixed and cleanups are made on top of that.
Specifics:
- Modify the driver core and the USB subsystem to allow USB devices
to stay suspended over system suspend/resume cycles if they have
been runtime-suspended already beforehand and fix some bugs on top
of these changes (Tomeu Vizoso, Rafael Wysocki).
- Update ACPICA to upstream revision 20160108, including updates of
the ACPICA's copyright notices, a code fixup resulting from a
regression fix that was necessary in the upstream code only (the
regression fixed by it has never been present in Linux) and a
compiler warning fix (Bob Moore, Lv Zheng).
- Fix a recent regression in the cpuidle menu governor that broke it
on practically all architectures other than x86 and make a couple
of optimizations on top of that fix (Rafael Wysocki).
- Clean up the selection of cpuidle governors depending on whether or
not the kernel is configured for tickless systems (Jean Delvare).
- Revert a recent commit that introduced a regression in the ACPI
backlight driver, address the problem it attempted to fix in a
different way and revert one more cosmetic change depending on the
problematic commit (Hans de Goede).
- Add two more ACPI backlight quirks (Hans de Goede).
- Fix a few minor problems in the core devfreq code, clean it up a
bit and update the MAINTAINERS information related to it (Chanwoo
Choi, MyungJoo Ham).
- Improve an error message in the ACPI fan driver (Andy Lutomirski).
- Fix a recent build regression in the cpupower tool (Shreyas
Prabhu)"
* tag 'pm+acpi-4.5-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (32 commits)
cpuidle: menu: Avoid pointless checks in menu_select()
sched / idle: Drop default_idle_call() fallback from call_cpuidle()
cpupower: Fix build error in cpufreq-info
cpuidle: Don't enable all governors by default
cpuidle: Default to ladder governor on ticking systems
time: nohz: Expose tick_nohz_enabled
ACPICA: Update version to 20160108
ACPICA: Silence a -Wbad-function-cast warning when acpi_uintptr_t is 'uintptr_t'
ACPICA: Additional 2016 copyright changes
ACPICA: Reduce regression fix divergence from upstream ACPICA
ACPI / video: Add disable_backlight_sysfs_if quirk for the Toshiba Satellite R830
ACPI / video: Revert "thinkpad_acpi: Use acpi_video_handles_brightness_key_presses()"
ACPI / video: Document acpi_video_handles_brightness_key_presses() a bit
ACPI / video: Fix using an uninitialized mutex / list_head in acpi_video_handles_brightness_key_presses()
ACPI / video: Revert "ACPI / video: driver must be registered before checking for keypresses"
ACPI / fan: Improve acpi_device_update_power error message
ACPI / video: Add disable_backlight_sysfs_if quirk for the Toshiba Portege R700
cpuidle: menu: Fix menu_select() for CPUIDLE_DRIVER_STATE_START == 0
MAINTAINERS: Add devfreq-event entry
MAINTAINERS: Add missing git repository and directory for devfreq
...
* pm-core:
driver core: Avoid NULL pointer dereferences in device_is_bound()
platform: Do not detach from PM domains on shutdown
USB / PM: Allow USB devices to remain runtime-suspended when sleeping
PM / sleep: Go direct_complete if driver has no callbacks
PM / Domains: add setter for dev.pm_domain
device core: add device_is_bound()
Pull drm updates from Dave Airlie:
"This is the main drm pull request for 4.5. I don't think I've missed
anything too major, I'm mostly back at work now but I'll probably get
some sleep in 5 years time.
Summary:
New drivers:
- etnaviv:
GPU driver for the 3D core on the Vivante core used in numerous
ARM boards.
Highlights:
Core:
- Atomic suspend/resume helpers
- Move the headers to using userspace friendlier types.
- Documentation updates
- Lots of struct_mutex removal.
- Bunch of DP MST fixes from AMD.
Panel:
- More DSI helpers
- Support for some new basic panels
i915:
- Basic Kabylake support
- DP link training and detect code refactoring
- fbc/psr fixes
- FIFO underrun fixes
- SDE interrupt handling fixes
- dma-buf/fence support in pageflip path.
- GPU side for MST audio support
radeon/amdgpu:
- Drop UMS support
- GPUVM/Scheduler optimisations
- Initial Powerplay support for Tonga/Fiji/CZ/ST
- ACP audio prerequisites
nouveau:
- GK20a instmem improvements
- PCIE link speed change support
msm:
- DSI support for msm8960/apq8064
tegra:
- Host1X support for Tegra210 SoC
vc4:
- 3D acceleration support
armada:
- Get rid of struct mutex
tda998x:
- Atomic modesetting support
- TMDS clock limitations
omapdrm:
- Atomic modesetting support
- improved TILER performance
rockchip:
- RK3036 VOP support
- Atomic modesetting support
- Synopsys DW MIPI DSI support
exynos:
- Runtime PM support
- of_graph binding for DP panels
- Cleanup of IPP code
- Configurable plane support
- Kernel panic fixes at release time"
* 'drm-next' of git://people.freedesktop.org/~airlied/linux: (711 commits)
drm/fb_cma_helper: Remove implicit call to disable_unused_functions
drm/amdgpu: add missing irq.h include
drm/vmwgfx: Fix a width / pitch mismatch on framebuffer updates
drm/vmwgfx: Fix an incorrect lock check
drm: nouveau: fix nouveau_debugfs_init prototype
drm/nouveau/pci: fix check in nvkm_pcie_set_link
drm/amdgpu: validate duplicates first
drm/amdgpu: move VM page tables to the LRU end on CS v2
drm/ttm: add ttm_bo_move_to_lru_tail function v2
drm/ttm: fix adding foreign BOs to the swap LRU
drm/ttm: fix adding foreign BOs to the LRU during init v2
drm/radeon: use kobj_to_dev()
drm/amdgpu: use kobj_to_dev()
drm/amdgpu/cz: force vce clocks when sclks are forced
drm/amdgpu/cz: force uvd clocks when sclks are forced
drm/amdgpu/cz: add code to enable forcing VCE clocks
drm/amdgpu/cz: add code to enable forcing UVD clocks
drm/amdgpu: fix lost sync_to if scheduler is enabled.
drm/amd/powerplay: fix static checker warning for return meaningless value.
drm/sysfs: use kobj_to_dev()
...
Since your main drm-next pull isn't out of the door yet I figured I might
as well flush out drm-misc instead of delaying for 4.6. It's really just
random stuff all over, biggest thing probably connector_mask tracking from
Maarten.
* tag 'topic/drm-misc-2016-01-17' of git://anongit.freedesktop.org/drm-intel: (24 commits)
drm/fb_cma_helper: Remove implicit call to disable_unused_functions
drm/sysfs: use kobj_to_dev()
drm/i915: Init power domains early in driver load
drm: Do not set connector->encoder in drivers
apple-gmux: Add initial documentation
drm: move MODULE_PARM_DESC to other file
drm/edid: index CEA/HDMI mode tables using the VIC
drm/atomic: Remove drm_atomic_connectors_for_crtc.
drm/i915: Update connector_mask during readout, v2.
drm: Remove opencoded drm_gem_object_release_handle()
drm: Do not set outparam on error during GEM handle allocation
drm/docs: more leftovers from the big vtable documentation pile
drm/atomic-helper: Reject legacy flips on a disabled pipe
drm/atomic: add connector mask to drm_crtc_state.
drm/tegra: Use __drm_atomic_helper_reset_connector for subclassing connector state, v2.
drm/atomic: Add __drm_atomic_helper_connector_reset, v2.
drm/i915: Set connector_state->connector using the helper.
drm: Use a normal idr allocation for the obj->name
drm: Only bump object-reference count when adding first handle
drm: Balance error path for GEM handle allocation
...
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>
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>
There are few defects in vga_get() related to signal hadning:
- we shouldn't check for pending signals for TASK_UNINTERRUPTIBLE
case;
- if we found pending signal we must remove ourself from wait queue
and change task state back to running;
- -ERESTARTSYS is more appropriate, I guess.
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Cc: stable@vger.kernel.org
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
neither ->release() nor ->poll() can be called unless ->open()
has succeeded on the same struct file, so checking for "has
open() failed" is pointless. What's more, ->poll() doesn't
return -E... - it always returns a bitmap of POLL... values,
so the dead code in that one had been actively bogus.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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 c8e9cf7bb2
("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>
The following functions iterate over the client list, invoke client
callbacks or invoke handler callbacks without locking anything at all:
- Introduced by c8e9cf7bb2 ("vga_switcheroo: Add a helper function to
get the client state"):
vga_switcheroo_get_client_state()
- Introduced by 0d69704ae3 ("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>
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 3e9e63dbd3
("vga_switcheroo: Add the support for audio clients"). Its use in
hda_intel.c was introduced by a82d51ed24 ("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 <tiwai@suse.de>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
[danvet: Add Takashi's clarification to the commit message.]
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
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 <lukas@wunner.de>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
debugfs_remove() gracefully ignores NULL parameters, so the explicit
checks can be removed.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Wrap overly long lines to make checkpatch happy. While at it, also add
blank lines after declarations to eliminate additional problems flagged
by checkpatch.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Use pr_fmt() to define the "vga_switcheroo: " prefix that is prepended
to all output messages emitted by pr_*() functions. This allows making
existing strings much shorter and eliminates a bunch of warnings from
checkpatch about lines being overly long.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
The header comment uses a weird combination of formatting styles. Make
it consistent.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Lukas Wunner
Linus Torvalds
Rafael J. Wysocki
Dave Airlie
Tomeu Vizoso
Al Viro
Kirill A. Shutemov
Rasmus Villemoes
Thierry Reding