Commit graph

4675 commits

Author SHA1 Message Date
Keith Packard
e489bda422 Merge branch 'drm-intel-fixes' into drm-intel-next 2011-06-29 13:47:53 -07:00
Jesse Barnes
1c70c0cebd drm/i915: enable ring freq scaling, RC6 and graphics turbo on Ivy Bridge v3
They use the same register interfaces, so we can simply enable the
existing code on IVB.

v2:
  - resolve conflict with ring freq scaling, we can enable it too
v3:
  - resolve conflict again, this time on drm-intel-next

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Keith Packard <keithp@keithp.com>
2011-06-29 13:47:29 -07:00
Ben Widawsky
dc501fbc43 drm/i915: Don't call describe_obj on NULL pointers
Reported-by: Pavel Roskin <proski@gnu.org>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=38777
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Keith Packard <keithp@keithp.com>
2011-06-29 13:05:52 -07:00
Keith Packard
d70bed1947 drm/i915: Hold struct_mutex during i915_save_state/i915_restore_state
Lots of register access in these functions, some of which requires the
struct mutex.

These functions now hold the struct mutex across the calls to
i915_save_display and i915_restore_display, and so the internal mutex
calls in those functions have been removed. To ensure that no-one else
was calling them (and hence violating the new required locking
invarient), those functions have been made static.

gen6_enable_rps locks the struct mutex, and so i915_restore_state
unlocks the mutex around calls to that function.

Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Keith Packard <keithp@keithp.com>
2011-06-29 11:20:45 -07:00
Keith Packard
8eb2c0ee67 Merge branch 'drm-intel-fixes' into drm-intel-next 2011-06-29 10:34:54 -07:00
Ben Widawsky
3e0dc6b01f drm/i915: hangcheck disable parameter
Provide a parameter to disable hanghcheck. This is useful mostly for
developers trying to debug known problems, and probably should not be
touched by normal users.

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Keith Packard <keithp@keithp.com>
2011-06-29 10:32:08 -07:00
Jesse Barnes
23b2f8bb92 drm/i915: load a ring frequency scaling table v3
The ring frequency scaling table tells the PCU to treat certain GPU
frequencies as if they were a given CPU frequency for purposes of
scaling the ring frequency.  Normally the PCU will scale the ring
frequency based on the CPU P-state, but with the table present, it will
also take the GPU frequency into account.

The main downside of keeping the ring frequency high while the CPU is
at a low frequency (or asleep altogether) is increased power
consumption.  But then if you're keeping your GPU busy, you probably
want the extra performance.

v2:
  - add units to debug table header (from Eric)
  - use tsc_khz as a fallback if the cpufreq driver doesn't give us a freq
    (from Chris)
v3:
  - fix comments & debug output
  - remove unneeded force wake get/put

Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Tested-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Keith Packard <keithp@keithp.com>
2011-06-28 13:54:27 -07:00
Linus Torvalds
0d72c6fcb5 Merge branch 'drm-intel-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/keithp/linux-2.6
* 'drm-intel-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/keithp/linux-2.6:
  drm/i915: Use chipset-specific irq installers
  drm/i915: forcewake fix after reset
  drm/i915: add Ivy Bridge page flip support
  drm/i915: split page flip queueing into per-chipset functions
2011-06-28 11:15:57 -07:00
Keith Packard
6ae77e6b6a Merge branch 'drm-intel-fixes' into drm-intel-next 2011-06-28 10:29:47 -07:00
Chris Wilson
f01c22fd59 drm/i915: Use chipset-specific irq installers
Konstantin Belousov pointed out that 4697995b98 replaced the generic
i915_driver_irq_*install() functions with chipset specific routines
accessible only through driver->irq_*install(). So update the sanity
check in i915_request_wait() to match.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Keith Packard <keithp@keithp.com>
2011-06-28 10:20:06 -07:00
Ben Widawsky
25732821cb drm/i915: forcewake fix after reset
The failure is as follows:

1. Userspace gets forcewake lock, lock count >=1
2. GPU hang/reset occurs (forcewake bit is reset)
3. count is now incorrect

The failure can only occur when using the forcewake userspace lock.

This has the unfortunate consequence of messing up the driver as well as
userspace, unless userspace closes the debugfs file, the kernel will
never end up waking the GT since the refcount will be > 1.

The solution is to try to recover the correct forcewake state based on
the refcount. There is a period of time where userspace reads/writes may
occur after the reset, before the GT has been forcewaked. The interface
was never designed to be a perfect solution for userspace reads/writes,
and the kernel portion is fixed by this patch.

Suggested-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Keith Packard <keithp@keithp.com>
2011-06-28 09:44:55 -07:00
Hugh Dickins
ecbec53b1d drm/i915: more struct_mutex locking
When auditing the locking in i915_gem.c (for a prospective change which
I then abandoned), I noticed two places where struct_mutex is not held
across GEM object manipulations that would usually require it.

Since one is in initial setup and the other in driver unload, I'm
guessing the mutex is not required for either; but post a patch in case
it is.

Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Keith Packard <keithp@keithp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-06-27 18:00:14 -07:00
Hugh Dickins
e2377fe0b6 drm/i915: use shmem_truncate_range
The interface to ->truncate_range is changing very slightly: once "tmpfs:
take control of its truncate_range" has been applied, this can be applied.
 For now there is only a slight inefficiency while this remains unapplied,
but it will soon become essential for managing shmem's use of swap.

Change i915_gem_object_truncate() to use shmem_truncate_range() directly:
which should also spare i915 later change if we switch from
inode_operations->truncate_range to file_operations->fallocate.

Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Keith Packard <keithp@keithp.com>
Cc: Dave Airlie <airlied@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-06-27 18:00:14 -07:00
Hugh Dickins
5949eac4d9 drm/i915: use shmem_read_mapping_page
Soon tmpfs will stop supporting ->readpage and read_cache_page_gfp(): once
"tmpfs: add shmem_read_mapping_page_gfp" has been applied, this patch can
be applied to ease the transition.

Make i915_gem_object_get_pages_gtt() use shmem_read_mapping_page_gfp() in
the one place it's needed; elsewhere use shmem_read_mapping_page(), with
the mapping's gfp_mask properly initialized.

Forget about __GFP_COLD: since tmpfs initializes its pages with memset,
asking for a cold page is counter-productive.

Include linux/shmem_fs.h also in drm_gem.c: with shmem_file_setup() now
declared there too, we shall remove the prototype from linux/mm.h later.

Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Keith Packard <keithp@keithp.com>
Cc: Dave Airlie <airlied@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-06-27 18:00:13 -07:00
Hugh Dickins
3142b651ad drm/ttm: use shmem_read_mapping_page
Soon tmpfs will stop supporting ->readpage and read_mapping_page(): once
"tmpfs: add shmem_read_mapping_page_gfp" has been applied, this patch can
be applied to ease the transition.

ttm_tt_swapin() and ttm_tt_swapout() use shmem_read_mapping_page() in
place of read_mapping_page(), since their swap_space has been created with
shmem_file_setup().

Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Dave Airlie <airlied@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-06-27 18:00:13 -07:00
Hugh Dickins
1e5216e438 drm/i915: more struct_mutex locking
When auditing the locking in i915_gem.c (for a prospective change which I
then abandoned), I noticed two places where struct_mutex is not held
across GEM object manipulations that would usually require it.  Since one
is in initial setup and the other in driver unload, I'm guessing the mutex
is not required for either; but post a patch in case it is.

Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Keith Packard <keithp@keithp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Keith Packard <keithp@keithp.com>
2011-06-27 17:00:35 -07:00
Keith Packard
8bc47de335 Merge branch 'drm-intel-fixes' into drm-intel-next 2011-06-26 19:12:00 -07:00
Jesse Barnes
7c9017e5b7 drm/i915: add Ivy Bridge page flip support
Use the blit ring for submitting flips since the render ring doesn't
generate flip complete interrupts.

Fixes bugs:

	https://bugs.freedesktop.org/show_bug.cgi?id=38362
	https://bugs.freedesktop.org/show_bug.cgi?id=38392
	https://bugs.freedesktop.org/show_bug.cgi?id=38393

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Tested-by:  Jian J Zhao <jian.j.zhao@intel.com>
Signed-off-by: Keith Packard <keithp@keithp.com>
2011-06-26 19:11:22 -07:00
Jesse Barnes
8c9f3aaf8e drm/i915: split page flip queueing into per-chipset functions
This makes things a little clearer and prevents us from running old code
on a new chipset that may not be supported.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewied-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Keith Packard <keithp@keithp.com>
2011-06-26 19:11:16 -07:00
Keith Packard
93dbb29b47 Merge branch 'drm-intel-fixes' into drm-intel-next 2011-06-25 17:08:13 -07:00
Linus Torvalds
536142f950 Merge branch 'drm-intel-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/keithp/linux-2.6
* 'drm-intel-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/keithp/linux-2.6:
  drm/i915: save/resume forcewake lock fixes
  Revert "drm/i915: Kill GTT mappings when moving from GTT domain"
  drm/i915: Apply HWSTAM workaround for BSD ring on SandyBridge
  drm/i915: Call intel_enable_plane from i9xx_crtc_mode_set (again)
2011-06-24 22:01:40 -07:00
Keith Packard
b97c3d9c16 drm/i915: i915_gem_object_finish_gtt must always release gtt mmap
Even if the object is no longer in the GTT domain, there may still be
a user space mapping which needs to be released.

Without this fix, render-based text (mostly in firefox) would
occasionally get corrupted when the system was under load.

Signed-off-by: Keith Packard <keithp@keithp.com>
2011-06-24 21:02:59 -07:00
Alex Deucher
ee4017f4ac drm/radeon/kms: handle special cases for vddc
A voltage value of 0xff01 requires that the driver
look up the max voltage for the board based using the
atom SetVoltage command table.

Setting the proper voltage should fix stability on
some newer asics.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2011-06-24 11:11:53 +10:00
Alex Deucher
d698a34da7 drm/radeon/kms: fix num_banks tiling config for fusion
The field is encoded:
0 = 4 banks
1 = 8 banks
2 = 16 banks

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2011-06-24 11:11:52 +10:00
Ben Widawsky
483f179899 drm/i915: save/resume forcewake lock fixes
The lock must be held for the saving and restoring of VGA state.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
CC: Alexander Zhaunerchyk <alex.vizor@gmail.com>
CC: Andrey Rahmatullin <wrar@wrar.name>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Keith Packard <keithp@keithp.com>
2011-06-22 10:28:33 -07:00
Keith Packard
2cd1176bd9 Merge branch 'drm-intel-fixes' into drm-intel-next 2011-06-21 12:02:57 -07:00
Eric Anholt
e92d03bff9 Revert "drm/i915: Kill GTT mappings when moving from GTT domain"
This reverts commit 4a684a4117.
Userland has always been required to set the object's domain to GTT
before using it through a GTT mapping, it's not something that the
kernel is supposed to enforce.  (The pagefault support is so that we
can handle multiple mappings without userland having to pin across
them, not so that userland can use GTT after GPU domains without
telling the kernel).

Fixes 19.2% +/- 0.8% (n=6) performance regression in cairo-gl
firefox-talos-gfx on my T420 latop.

Signed-off-by: Keith Packard <keithp@keithp.com>
2011-06-21 11:11:02 -07:00
Chris Wilson
ec6a890dfe drm/i915: Apply HWSTAM workaround for BSD ring on SandyBridge
...we need to apply exactly the same workaround for missing interrupts
from BSD as for the BLT ring, apparently.

See also commit 498e720b96
(drm/i915: Fix gen6 (SNB) missed BLT ring interrupts).

Reported-and-tested-by: nkalkhof@web.de
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=38529
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Keith Packard <keithp@keithp.com>
2011-06-21 10:57:23 -07:00
Keith Packard
efc2924e73 drm/i915: Call intel_enable_plane from i9xx_crtc_mode_set (again)
This change got placed in the ironlake path instead of the 9xx path
during a recent code shuffle.

Signed-off-by: Keith Packard <keithp@keithp.com>
2011-06-21 10:57:05 -07:00
Alex Deucher
a377e187df drm/radeon/kms/r6xx+: voltage fixes
0xff01 is not an actual voltage value, but a flag
for the driver.  If the power state as that value,
skip setting the voltage.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2011-06-21 09:38:25 +10:00
Dave Airlie
4ee1c57fca drm/nouveau: drop leftover debugging
this printk isn't really useful, just drop it for now.

Signed-off-by: Dave Airlie <airlied@redhat.com>
2011-06-20 15:27:18 +10:00
Dave Airlie
ca295e50c2 Merge branch 'drm-nouveau-fixes' of git://anongit.freedesktop.org/git/nouveau/linux-2.6 into drm-fixes
* 'drm-nouveau-fixes' of git://anongit.freedesktop.org/git/nouveau/linux-2.6:
  drm/nouveau: fix assumption that semaphore dmaobj is valid in x-chan sync
  drm/nv50/disp: fix gamma with page flipping overlay turned on
  drm/nouveau/pm: Prevent overflow in nouveau_perf_init()
  drm/nouveau: fix big-endian switch
2011-06-20 12:02:38 +10:00
Dave Airlie
682f1a54a0 drm/radeon: avoid warnings from r600/eg irq handlers on powered off card.
Since we were calling the wptr function before checking if the IH was
even enabled, or the GPU wasn't shutdown, we'd get spam in the logs when
the GPU readback 0xffffffff. This reorders things so we return early
in the no IH and GPU shutdown cases.

Reported-and-tested-by: ManDay on #radeon
Reviewed-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2011-06-20 12:01:43 +10:00
Alex Deucher
74d074eecb drm/radeon/kms: add missing param for dce3.2 DP transmitter setup
This is used during phy init to set up the phy for DP.  This may
fix DP problems on DCE3.2 cards.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2011-06-20 09:53:02 +10:00
Alex Deucher
8323fa6ba3 drm/radeon/kms/atom: fix duallink on some early DCE3.2 cards
Certain revisions of the vbios on DCE3.2 cards have a bug
in the transmitter control table which prevents duallink from
being enabled properly on some cards.  The action switch statement
jumps to the wrong offset for the OUTPUT_ENABLE action.  The fix
is to use the ENABLE action rather than the OUTPUT_ENABLE action
on the affected cards.  In fixed version of the vbios, both
actions jump to the same offset, so the change should be safe.

Reported-and-tested-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
2011-06-20 09:52:24 +10:00
Ben Skeggs
b16a5a18ff drm/nouveau: fix assumption that semaphore dmaobj is valid in x-chan sync
The DDX modifies DMA_SEMAPHORE on nv50 in order to implement sync-to-vblank,
things will go very wrong for cross-channel sync after this.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
2011-06-18 14:56:24 +10:00
Ben Skeggs
f66b3d5540 drm/nv50/disp: fix gamma with page flipping overlay turned on
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
2011-06-18 14:38:45 +10:00
Emil Velikov
2905544073 drm/nouveau/pm: Prevent overflow in nouveau_perf_init()
While parsing the perf table, there is no check if
the num of entries read from the vbios is less than
the currently allocated number.

In case of a buggy vbios this will cause overwriting
of kernel memory, causing aditional problems.

Add a simple check in order to prevent the case

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
2011-06-18 14:38:38 +10:00
Ben Skeggs
0897554cdd drm/nouveau: fix big-endian switch
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
2011-06-18 14:38:27 +10:00
Daniel J Blueman
498e720b96 drm/i915: Fix gen6 (SNB) missed BLT ring interrupts.
The failure appeared in dmesg as:

[drm:i915_hangcheck_ring_idle] *ERROR* Hangcheck timer elapsed... blt
ring idle [waiting on 35064155, at 35064155], missed IRQ?

This works around that problem on by making the blitter command
streamer write interrupt state to the Hardware Status Page when a
MI_USER_INTERRUPT command is decoded, which appears to force the seqno
out to memory before the interrupt happens.

v1->v2: Moved to prior interrupt handler installation and RMW flags as
per feedback.
v2->v3: Removed RMW of flags (by anholt)

Cc: stable@kernel.org
Signed-off-by: Daniel J Blueman <daniel.blueman@gmail.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Tested-by: Chris Wilson <chris@chris-wilson.co.uk> [v1]
Tested-by: Eric Anholt <eric@anholt.net> [v1,v3]
	   (incidence of the bug with a testcase went from avg 2/1000 to
	   0/12651 in the latest test run (plus more for v1))
Tested-by: Kenneth Graunke <kenneth@whitecape.org> [v1]
Tested-by: Robert Hooker <robert.hooker@canonical.com> [v1]
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=33394
Signed-off-by: Dave Airlie <airlied@redhat.com>
2011-06-18 08:25:16 +10:00
Alex Deucher
b81157d016 drm/radeon/kms: use helper functions for fence read/write
The existing code assumed scratch registers in a number
of places while in most cases we are be using writeback
and events rather than scratch registers.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2011-06-17 09:30:04 +10:00
Alex Deucher
11b0a5b89a drm/radeon/kms: set DP link config properly for DP bridges
DP clock and lanes were not set properly for DP bridges.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2011-06-17 09:28:11 +10:00
Alex Deucher
cc9f67a0a0 drm/radeon/kms/atom: AdjustPixelClock fixes for DP bridges
Need to set the external transmitter type properly in
AdjustPixelClock to get the properly output.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2011-06-17 09:28:10 +10:00
Alex Deucher
f89931f345 drm/radeon/kms: fix handling of DP to LVDS bridges
They need to be treated like eDP rather than DP.

May fix:
https://bugzilla.kernel.org/show_bug.cgi?id=34822

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2011-06-17 09:28:07 +10:00
Alex Deucher
d6c669528a drm/radeon/kms: issue blank/unblank commands for ext encoders
Required for DPMS on some systems.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2011-06-17 09:28:05 +10:00
Alex Deucher
591a10e16c drm/radeon/kms: fix support for DDC on dp bridges
Need to set up the bridge for DDC prior to the
i2c over aux transaction.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2011-06-17 09:28:03 +10:00
Alex Deucher
d629a3ceb4 drm/radeon/kms: add support for load detection on dp bridges
dp to vga bridges for example.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2011-06-17 09:28:02 +10:00
Alex Deucher
7ec478f835 drm/radeon/kms: add missing external encoder action
required for ddc.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2011-06-17 09:28:01 +10:00
Alex Deucher
fbb8777365 drm/radeon/kms: rework atombios_get_encoder_mode()
This should give us more reliable results if the table
is called before an active device is set.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2011-06-17 09:27:59 +10:00
Alex Deucher
ba7e05e958 drm/radeon/kms: fix num crtcs for Cedar and Caicos
Only support 4 rather than 6.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2011-06-17 09:24:29 +10:00