linux/include
Lukas Wunner b00e5334ab 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 412c8f7de0 ("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
2016-05-31 13:15:57 +02:00
..
acpi device property: Avoid potential dereferences of invalid pointers 2016-04-27 23:40:02 +02:00
asm-generic asm-generic/futex: Re-enable preemption in futex_atomic_cmpxchg_inatomic() 2016-04-21 11:06:09 +02:00
clocksource
crypto Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2016-03-17 11:33:45 -07:00
drm drm: use seqlock for vblank time/count 2016-05-24 23:21:56 +02:00
dt-bindings clk: mediatek: Add hdmi_ref HDMI PHY PLL reference clock output 2016-05-06 17:47:40 +02:00
keys
kvm arm64: KVM: vgic-v3: Avoid accessing ICH registers 2016-03-09 04:24:04 +00:00
linux vga_switcheroo: Add helper for deferred probing 2016-05-31 13:15:57 +02:00
math-emu
media [media] media: vb2: Fix regression on poll() for RW mode 2016-04-25 10:21:23 -03:00
memory
misc cxl: Remove cxl_get_phys_dev() kernel API 2016-03-09 23:40:02 +11:00
net vxlan: Add checksum check to the features check function 2016-05-03 16:00:54 -04:00
pcmcia
ras
rdma IB/security: Restrict use of the write() interface 2016-04-28 12:03:16 -04:00
rxrpc rxrpc: Be more selective about the types of received packets we accept 2016-03-04 15:56:06 +00:00
scsi Merge branch 'fixes-base' into fixes 2016-04-05 06:56:47 -04:00
soc IOMMU Updates for Linux v4.6 2016-03-22 11:57:43 -07:00
sound ALSA: hda - Update BCLK also at hotplug for i915 HSW/BDW 2016-04-26 10:11:11 +02:00
target target: add a new add_wwn_groups fabrics method 2016-03-30 20:06:44 -07:00
trace Merge branch 'for-linus-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs 2016-04-09 10:41:34 -07:00
uapi drm/vmwgfx: add extern C guard for the UAPI header 2016-05-13 14:06:21 +01:00
video drm/exynos: clean up register definions for fimd and decon 2016-04-30 11:34:14 +09:00
xen xen: Fix page <-> pfn conversion on 32 bit systems 2016-04-06 11:18:17 +01:00
Kbuild