This hooks radeon up to the runtime PM system to enable
dynamic power management for secondary GPUs in switchable
and powerxpress laptops.

v2: agd5f: clean up, add module parameter
Signed-off-by: NDave Airlie <airlied@redhat.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

Commit a01c34f7 (radeon kms: do not
flush uninitialized hotplug work) moved work initialisation phase to
the last step of radeon_irq_kms_init(). Meelis Roos reported that this
causes problems on his machine because drm_irq_install() uses hotplug
work on r100.

hotplug work flushed in radeon_irq_kms_fini(), with two possible cases:
-- radeon_irq_kms_fini() call after successful radeon_irq_kms_init()
-- radeon_irq_kms_fini() call after unsuccessful (or not called at all)
   radeon_irq_kms_init()

The latter one causes flush work on uninitialised hotplug work. Move
work initialisation before drm_irq_install(), but keep existing agreement
to flush hotplug work in radeon_irq_kms_fini() only for `irq.installed'
(successful radeon_irq_kms_init()) case.

WARNING: CPU: 0 PID: 243 at kernel/workqueue.c:1378 __queue_work+0x132/0x16d()
Call Trace:
[<c12319b3>] ? dump_stack+0xa/0x13
[<c1022600>] ? warn_slowpath_common+0x75/0x8a
[<c1031010>] ? __queue_work+0x132/0x16d
[<c1031010>] ? __queue_work+0x132/0x16d
[<c102269e>] ? warn_slowpath_null+0x1b/0x1f
[<c1031010>] ? __queue_work+0x132/0x16d
[<c103107b>] ? queue_work_on+0x30/0x40
[<f8aed3f3>] ? r100_irq_process+0x16d/0x1e6 [radeon]
[<f8ae77cf>] ? radeon_driver_irq_preinstall_kms+0xc2/0xc5 [radeon]
[<f8974d77>] ? drm_irq_install+0xb2/0x1ac [drm]
[<f897604d>] ? drm_vblank_init+0x196/0x1d2 [drm]
[<f8ae78d3>] ? radeon_irq_kms_init+0x33/0xc6 [radeon]
[<f8aef35a>] ? r100_startup+0x1a3/0x1d6 [radeon]
[<f8ad77c8>] ? radeon_ttm_init+0x26e/0x287 [radeon]
[<f8aef752>] ? r100_init+0x2b3/0x309 [radeon]
[<c118082e>] ? vga_client_register+0x39/0x40
[<f8ac535f>] ? radeon_device_init+0x54b/0x61b [radeon]
[<f8ac40fd>] ? cail_mc_write+0x13/0x13 [radeon]
[<f8ac6864>] ? radeon_driver_load_kms+0x82/0xda [radeon]
[<f8978bbd>] ? drm_get_pci_dev+0x136/0x22d [drm]
[<f8ac409b>] ? radeon_pci_probe+0x6c/0x86 [radeon]
[<c112acf6>] ? pci_device_probe+0x4c/0x83
[<c11846c7>] ? driver_probe_device+0x80/0x184
[<c112a848>] ? pci_match_id+0x18/0x36
[<c1184837>] ? __driver_attach+0x44/0x5f
[<c11833f4>] ? bus_for_each_dev+0x50/0x5a
[<c118433e>] ? driver_attach+0x14/0x16
[<c11847f3>] ? __device_attach+0x28/0x28
[<c1184045>] ? bus_add_driver+0xd6/0x1bf
[<c1184c22>] ? driver_register+0x78/0xcf
[<f8ba8000>] ? 0xf8ba7fff
[<c10003bf>] ? do_one_initcall+0x8b/0x121
[<c101e668>] ? change_page_attr_clear+0x2e/0x33
[<f8ba8000>] ? 0xf8ba7fff
[<c101e689>] ? set_memory_ro+0x1c/0x20
[<c104de94>] ? set_page_attributes+0x11/0x12
[<c104f6e1>] ? load_module+0x12fa/0x17e8
[<c107483b>] ? map_vm_area+0x22/0x31
[<c104fc36>] ? SyS_init_module+0x67/0x7d
[<c1234245>] ? sysenter_do_call+0x12/0x26
Reported-by: NMeelis Roos <mroos@linux.ee>
Tested-by: NMeelis Roos <mroos@linux.ee>
Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

Fix a warning from lockdep caused by calling flush_work() for
uninitialized hotplug work. Initialize hotplug_work, audio_work
and reset_work upon successful radeon_irq_kms_init() completion
and thus perform hotplug flush_work only when rdev->irq.installed
is true.

[    4.790019] [drm] Loading CEDAR Microcode
[    4.790943] r600_cp: Failed to load firmware "radeon/CEDAR_smc.bin"
[    4.791152] [drm:evergreen_startup] *ERROR* Failed to load firmware!
[    4.791330] radeon 0000:01:00.0: disabling GPU acceleration

[    4.792633] INFO: trying to register non-static key.
[    4.792792] the code is fine but needs lockdep annotation.
[    4.792953] turning off the locking correctness validator.

[    4.793114] CPU: 2 PID: 1 Comm: swapper/0 Not tainted 3.11.0-rc0-dbg-10676-gfe56456-dirty #1816
[    4.793314] Hardware name: Acer             Aspire 5741G    /Aspire 5741G    , BIOS V1.20 02/08/2011
[    4.793507]  ffffffff821fd810 ffff8801530b9a18 ffffffff8160434e 0000000000000002
[    4.794155]  ffff8801530b9ad8 ffffffff810b8404 ffff8801530b0798 ffff8801530b0000
[    4.794789]  ffff8801530b9b00 0000000000000046 00000000000004c0 ffffffff00000000
[    4.795418] Call Trace:
[    4.795573]  [<ffffffff8160434e>] dump_stack+0x4e/0x82
[    4.795731]  [<ffffffff810b8404>] __lock_acquire+0x1a64/0x1d30
[    4.795893]  [<ffffffff814a87f0>] ? dev_vprintk_emit+0x50/0x60
[    4.796034]  [<ffffffff810b8fb4>] lock_acquire+0xa4/0x200
[    4.796216]  [<ffffffff8106cd75>] ? flush_work+0x5/0x280
[    4.796375]  [<ffffffff8106cdad>] flush_work+0x3d/0x280
[    4.796520]  [<ffffffff8106cd75>] ? flush_work+0x5/0x280
[    4.796682]  [<ffffffff810b659d>] ? trace_hardirqs_on_caller+0xfd/0x1c0
[    4.796862]  [<ffffffff8131d775>] ? delay_tsc+0x95/0xf0
[    4.797024]  [<ffffffff8141bb8b>] radeon_irq_kms_fini+0x2b/0x70
[    4.797186]  [<ffffffff814557c9>] evergreen_init+0x2a9/0x2e0
[    4.797347]  [<ffffffff813ebb1f>] radeon_device_init+0x5ef/0x700
[    4.797511]  [<ffffffff81335bc7>] ? pci_find_capability+0x47/0x50
[    4.797672]  [<ffffffff813edaed>] radeon_driver_load_kms+0x8d/0x150
[    4.797843]  [<ffffffff813ce426>] drm_get_pci_dev+0x166/0x280
[    4.798007]  [<ffffffff8116cff5>] ? kfree+0xf5/0x2e0
[    4.798168]  [<ffffffff813ea298>] ? radeon_pci_probe+0x98/0xd0
[    4.798329]  [<ffffffff813ea2aa>] radeon_pci_probe+0xaa/0xd0
[    4.798489]  [<ffffffff81339404>] pci_device_probe+0x84/0xe0
[    4.798644]  [<ffffffff814ac7d6>] driver_probe_device+0x76/0x240
[    4.798805]  [<ffffffff814aca73>] __driver_attach+0x93/0xa0
[    4.798948]  [<ffffffff814ac9e0>] ? __device_attach+0x40/0x40
[    4.799126]  [<ffffffff814aa82b>] bus_for_each_dev+0x6b/0xb0
[    4.799272]  [<ffffffff814ac2be>] driver_attach+0x1e/0x20
[    4.799434]  [<ffffffff814abec0>] bus_add_driver+0x1f0/0x280
[    4.799596]  [<ffffffff814ad0e4>] driver_register+0x74/0x150
[    4.799758]  [<ffffffff8133923d>] __pci_register_driver+0x5d/0x60
[    4.799936]  [<ffffffff81d16efc>] ? ttm_init+0x67/0x67
[    4.800081]  [<ffffffff813ce655>] drm_pci_init+0x115/0x130
[    4.800243]  [<ffffffff81d16efc>] ? ttm_init+0x67/0x67
[    4.800405]  [<ffffffff81d16f98>] radeon_init+0x9c/0xba
[    4.800586]  [<ffffffff810002ca>] do_one_initcall+0xfa/0x150
[    4.800746]  [<ffffffff81073f60>] ? parse_args+0x120/0x330
[    4.800909]  [<ffffffff81cdafae>] kernel_init_freeable+0x111/0x191
[    4.801052]  [<ffffffff81cda87a>] ? do_early_param+0x88/0x88
[    4.801233]  [<ffffffff815fb670>] ? rest_init+0x140/0x140
[    4.801393]  [<ffffffff815fb67e>] kernel_init+0xe/0x180
[    4.801556]  [<ffffffff8160dcac>] ret_from_fork+0x7c/0xb0
[    4.801718]  [<ffffffff815fb670>] ? rest_init+0x140/0x140
Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

This adds dpm support for rv6xx asics.  This includes:
- clockgating
- dynamic engine clock scaling
- dynamic memory clock scaling
- dynamic voltage scaling
- dynamic pcie gen1/gen2 switching

Set radeon.dpm=1 to enable.

v2: remove duplicate line
v3: fix thermal interrupt check noticed by Jerome
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Reviewed-by: NChristian König <christian.koenig@amd.com>

New asics support non-privileged IBs.  This allows us
to skip IB checking in the driver since the hardware
will check the command buffers for us.  When using
non-privileged IBs, if the CP encounters an illegal
register in the command stream, it will halt and generate
an interrupt.  The CP needs to be reset to continue.  For now
just do a full GPU reset when this happens.
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

Signed-off-by: NMasanari Iida <standby24x7@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Avoids splatter if the interrupt handler is not registered due
to acceleration being disabled.
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Reviewed-by: NJerome Glisse <jglisse@redhat.com>
Cc: stable@vger.kernel.org

Convert #include "..." to #include <path/...> in drivers/gpu/.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NDave Airlie <airlied@redhat.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: NDave Jones <davej@redhat.com>

There are so many quirks, lets just try and force
this for all RS690s.  See:
https://bugs.freedesktop.org/show_bug.cgi?id=37679Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

Fixes another system on:
https://bugs.freedesktop.org/show_bug.cgi?id=37679Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

It was only used for dynpm, but has been replaced with
a better implementation using fences.  Remove it.
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

flush[_delayed]_work_sync() are now spurious.  Mark them deprecated
and convert all users to flush[_delayed]_work().

If you're cc'd and wondering what's going on: Now all workqueues are
non-reentrant and the regular flushes guarantee that the work item is
not pending or running on any CPU on return, so there's no reason to
use the sync flushes at all and they're going away.

This patch doesn't make any functional difference.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Mattia Dongili <malattia@linux.it>
Cc: Kent Yoder <key@linux.vnet.ibm.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Bryan Wu <bryan.wu@canonical.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-wireless@vger.kernel.org
Cc: Anton Vorontsov <cbou@mail.ru>
Cc: Sangbeom Kim <sbkim73@samsung.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Petr Vandrovec <petr@vandrovec.name>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Avi Kivity <avi@redhat.com> 

Adds documentation to most of the functions in
radeon_irq_kms.c
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Reviewed-by: NChristian König <christian.koenig@amd.com>

So we can skip the locking. Also renames sw_int to
ring_int, cause that better matches its purpose.
Signed-off-by: NChristian Koenig <christian.koenig@amd.com>

1. It is really dangerous to have more than one
   spinlock protecting the same information.

2. radeon_irq_set sometimes wasn't called with lock
   protection, so it can happen that more than one
   CPU would tamper with the irq regs at the same
   time.

3. The pm.gui_idle variable was assuming that the 3D
   engine wasn't becoming idle between testing the
   register and setting the variable. So just remove
   it and test the register directly.

v2: Also handle the hpd irq code the same way.
v3: Rename hpd parameter for clarification.
Signed-off-by: NChristian Koenig <christian.koenig@amd.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>

- add support for rs6xx
- add support for DCE4/5
- fixup 6xx/7xx
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

My rv515 card is very flaky with msi enabled. Every so often it loses a rearm
and never comes back, manually banging the rearm brings it back.
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: NDave Airlie <airlied@redhat.com>

Interrupts only work with MSIs.
https://bugs.freedesktop.org/show_bug.cgi?id=37679Reported-by: NDmitry Podgorny <pasis.uax@gmail.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: NDave Airlie <airlied@redhat.com>

Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NChristian König <deathsimple@vodafone.de>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Allow the user to override whether MSIs are enabled
or not on supported ASICs.  MSIs are disabled by default
on IGP chips as they tend not to work.  However certain
IGP chips only seem to work with MSIs enabled.

I suspect this is a chipset or bios issue, but I'm not sure
what the proper fix is.  This will at least make diagnosing
and working around the problem much easier.

See:
https://bugs.freedesktop.org/show_bug.cgi?id=37679Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@kernel.org
Signed-off-by: NDave Airlie <airlied@redhat.com>

Some Dell laptops only seem to work with MSIs.  This
looks like a platform/bios bug.

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=37679Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@kernel.org
Signed-off-by: NDave Airlie <airlied@redhat.com>

Some HP laptops only seem to work with MSIs.  This
looks like a platform/bios bug.

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=37679Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@kernel.org
Signed-off-by: NDave Airlie <airlied@redhat.com>

This makes it easier to add quirks for certain systems.
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@kernel.org
Signed-off-by: NDave Airlie <airlied@redhat.com>

radeon_driver_irq_preinstall_kms and radeon_driver_irq_uninstall_kms
hard code the loop to 6 which happens to be the current maximum
number of crtcs and hpd pins; if one day an ASIC with more crtcs
(or hpd pins) comes out, this is a trouble waiting to happen.

introduce constants for maximum CRTC count, maximum HPD pins count
and maximum HDMI blocks count (per FIXME in radeon_irq structure)
and correct the loops in radeon_driver_irq_preinstall_kms and
radeon_driver_irq_uninstall_kms

v2: take care of goofs pointed out by Alex Deucher
Signed-off-by: NIlija Hadzic <ihadzic@research.bell-labs.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

I'm amazed but not really surprised this worked on x86...
Signed-off-by: NMichel Dänzer <daenzer@vmware.com>
Signed-off-by: NDave Airlie <airlied@gmail.com>

With cmwq, there's no reason for radeon to use a dedicated workqueue.
Drop dev_priv->wq and use system_wq instead.

Because radeon_driver_irq_uninstall_kms() may be called from
unsleepable context, the work items can't be flushed from there.
Instead, init and flush from radeon_irq_kms_init/fini().

While at it, simplify canceling/flushing of rdev->pm.dynpm_idle_work.
Always initialize and sync cancel instead of being unnecessarily smart
about it.
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NAlex Deucher <alexdeucher@gmail.com>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: NDave Airlie <airlied@redhat.com>

Signed-off-by: NAlex Deucher <alexdeucher@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

This adds support for dri2 pageflipping.

v2: precision updates from Mario Kleiner.
v3: Multihead fixes from Mario Kleiner; missing crtc offset
    add note about update pending bit on pre-avivo chips
Signed-off-by: NAlex Deucher <alexdeucher@gmail.com>
Signed-off-by: NMario Kleiner <mario.kleiner@tuebingen.mpg.de>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=29327Signed-off-by: NAlex Deucher <alexdeucher@gmail.com>
Cc: stable@kernel.org
Signed-off-by: NDave Airlie <airlied@redhat.com>

Useful for certain power management operations.  You
need to wait for the GUI engine (2D, 3D, CP, etc.) to be
idle before changing clocks or adjusting engine parameters.

(v2) Fix gui idle enable on pre-r6xx asics

(v3) The gui idle interrrupt status bit is permanently asserted
on pre-r6xx chips, but the interrrupt is still generated.
workaround it in the driver.

(v4) Add support for evergreen
Signed-off-by: NAlex Deucher <alexdeucher@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

After thinking it over a lot it made more sense for the core to deal with
the output polling especially so it can notify X.

v2: drop plans for fake connector - per Michel's comments - fix X patch sent to xorg-devel, add intel polled/hpd setting, add initial nouveau polled/hpd settings.

v3: add config lock take inside polling, add intel/nouveau poll init/fini calls

v4: config lock was a bit agressive, only needed around connector list reading.
otherwise it could re-enter.

glisse: discard drm_helper_hpd_irq_event

v3: Reviewed-by: Michel Dänzer <michel@daenzer.net>
Signed-off-by: NDave Airlie <airlied@redhat.com>

When we are running in a headless environment we have no idea what
output the user might plug in later, we only have hotplug detect
from the digital outputs. So if we detect no connected outputs at
initialisation, start a slow work operation to poll every 5 seconds
for an output.

this is only hooked up for radeon so far, on hw where we have full
hotplug detection there is no need for this.
Signed-off-by: NDave Airlie <airlied@redhat.com>

The fbdev layer in the kms code should act like a consumer of the kms services and avoid having relying on information being store in the kms core structures in order for it to work.

This patch

a) removes the info pointer/psuedo palette from the core drm_framebuffer structure and moves it to the fbdev helper layer, it also removes the core drm keeping a list of kernel kms fbdevs.
b) migrated all the fb helper functions out of the crtc helper file into the fb helper file.
c) pushed the fb probing/hotplug control into the driver
d) makes the surface sizes into a structure for ease of passing
This changes the intel/radeon/nouveau drivers to use the new helper.
Signed-off-by: NDave Airlie <airlied@redhat.com>

Doesn't seem to work reliably and the pci quirks don't
always work.
Signed-off-by: NAlex Deucher <alexdeucher@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Replace hardcoded numbers with rdev->num_crtc.
Signed-off-by: NAlex Deucher <alexdeucher@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

AMD says in section 2.5.4 (GFX MSI Enable) of #43291 (AMD 780G Family
Register Programming Requirements):

  The SBIOS must enable internal graphics MSI capability in GCCFG by
  setting the following: NBCFG.NB_CNTL.STRAP_MSI_ENABLE='1'

Quite a few BIOS writers misinterpret this sentence and think that
enabling MSI is an optional feature.  However, clearing that bit just
prevents delivery of MSI messages but does not remove the MSI PCI
capabilities registers, and so leaves these devices unusable for any
driver that attempts to use MSI.

Setting that bit is not possible after the BIOS has locked down the
configuration registers, so we have to manually disable MSI for the
affected devices.

This fixes the codec communication errors in the HDA driver when
accessing the HDMI audio device, and allows us to get rid of the
overcautious quirk in radeon_irq_kms.c.
Signed-off-by: NClemens Ladisch <clemens@ladisch.de>
Tested-by: NAlex Deucher <alexdeucher@gamil.com>
Cc: <stable@kernel.org>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

If for any reason we haven't installed handler we shouldn't try to
enable IRQ/MSI on the hw so we don't get unhandled IRQ/MSI which
makes the kernel sad.
Signed-off-by: NJerome Glisse <jglisse@redhat.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

This enabled interrupt driven hpd support for all
radeon chips.  Assuming the hpd pin is wired up
correctly, the driver will generate uevents on
digital monitor connect and disconnect and retrain
DP monitors automatically.
Signed-off-by: NAlex Deucher <alexdeucher@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

We really don't need to process every irq that comes in, we only
really want to do SW irq processing when we are actually waiting for
a fence to pass. I'm not 100% sure this is race free esp on non-MSI systems
so it needs some testing.
Signed-off-by: NDave Airlie <airlied@redhat.com>

This enables the use of interrupts on r6xx/r7xx hardware.
Interrupts are implemented via a ring buffer.  The GPU adds
interrupts vectors to the ring and the host reads them off
in the interrupt handler.  The interrupt controller requires
firmware like the CP.  This firmware must be installed and
accessble to the firmware loader for interrupts to function.

MSIs don't seem to work on my RS780.  They work fine on all
my discrete cards.  I'm not sure about other RS780s or
RS880s.  I've disabled MSIs on RS780 and RS880, but it would
probably be worth checking on some other systems.

v2 - fix some checkpatch.pl problems;
     re-read the disp int status reg if we restart the ih;

v3 - remove the irq handler if r600_irq_init() fails;
     remove spinlock in r600_ih_ring_fini();
     move ih rb overflow check to r600_get_ih_wptr();
     move irq ack to separate function;
Signed-off-by: NAlex Deucher <alexdeucher@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>