This is a moral revert of 6ec3d0c0.

Following the fix to reset the GMBUS controller after a NAK, we finally
utilize the 0xa0 probe for a CRT connection. And discover that the code
is broken. Shock.

There are a number of issues, but following a key insight from Dave
Airlie, that 0xA0 is an invalid address on a 7-bit bus (though not if we
were to enable 10-bit addressing), and would look like the EDID port
0x50, it is possible to see where the confusion starts.

In short, a write to 0xA0 is accepted by the GMBUS controller which we
interpreted as meaning the existence of a connection (a slave on the
other end of the wire ACKing the write). That was false.

During testing with a broken GMBUS implementation, which never reset an
earlier NAK, this test always reported a NAK and so we proceeded on to
the next test.
Reported-and-tested-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=35904Reported-and-tested-by: Riccardo Magliocchetti <riccardo.magliocchetti@gmail.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=32612Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Dave Airlie <airlied@linux.ie>
Signed-off-by: Keith Packard <keithp@keithp.com>

Once a NAK has been asserted by the slave, we need to reset the GMBUS
controller in order to continue. This is done by asserting the Software
Clear Interrupt bit and then clearing it again to restore operations.

If we don't clear the NAK, then all future GMBUS xfers will fail,
including DDC probes and EDID retrieval.

v2: Add some comments as suggested by Keith Packard.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=35781Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Keith Packard <keithp@keithp.com>
Tested-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Tested-by: "Mengmeng Meng" <mengmeng.meng@intel.com>

During modesetting, we need to wait for the hardware to report
readiness by polling the registers. Normally, we call msleep() between
reads, because some state changes may take a whole vblank or more
to complete. However during a panic, we are in an atomic context and
cannot sleep. Instead, busy spin polling the termination condition.

References: https://bugzilla.kernel.org/show_bug.cgi?id=31772Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>

The LVDS connector should default to connected. We tried our best to
verify the claims of the BIOS that the hardware exists during init(),
and then during detect() we then try to verify that the panel is open.
In the event of an unsuccessful query, we should then always report
that the LVDS panel is connected. This was only the case for gen2/3,
later generations leaked the return value from the panel probe instead.
Reported-and-tested-by: Alessandro Suardi <alessandro.suardi@gmail.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Keith Packard <keithp@keithp.com>

This reverts commit a7a75c8f.

There are two different variations on how Intel hardware addresses the
"Hardware Status Page". One as a location in physical memory and the
other as an offset into the virtual memory of the GPU, used in more
recent chipsets. (The HWS itself is a cacheable region of memory which
the GPU can write to without requiring CPU synchronisation, used for
updating various details of hardware state, such as the position of
the GPU head in the ringbuffer, the last breadcrumb seqno, etc).

These two types of addresses were updated in different locations of code
- one inline with the ringbuffer initialisation, and the other during
device initialisation. (The HWS page is logically associated with
the rings, and there is one HWS page per ring.) During resume, only the
ringbuffers were being re-initialised along with the virtual HWS page,
leaving the older physical address HWS untouched. This then caused a
hang on the older gen3/4 (915GM, 945GM, 965GM) the first time we tried
to synchronise the GPU as the breadcrumbs were never being updated.
Reported-and-tested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: Jan Niehusmann <jan@gondor.com>
Reported-and-tested-by: Justin P. Mattock <justinmattock@gmail.com>
Reported-and-tested-by: Michael "brot" Groh <brot@minad.de>
Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Zhenyu Wang <zhenyuw@linux.intel.com>

Found by gem_stress.

As we perform retirement from a workqueue, it is possible for us to free
and unbind objects after the last close on the device, and so after the
address space has been torn down and reset to NULL:

BUG: unable to handle kernel NULL pointer dereference at 00000054
IP: [<c1295a20>] mutex_lock+0xf/0x27
*pde = 00000000
Oops: 0002 [#1] SMP
last sysfs file: /sys/module/vt/parameters/default_utf8

Pid: 5, comm: kworker/u:0 Not tainted 2.6.38+ #214
EIP: 0060:[<c1295a20>] EFLAGS: 00010206 CPU: 1
EIP is at mutex_lock+0xf/0x27
EAX: 00000054 EBX: 00000054 ECX: 00000000 EDX: 00012fff
ESI: 00000028 EDI: 00000000 EBP: f706fe20 ESP: f706fe18
 DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
Process kworker/u:0 (pid: 5, ti=f706e000 task=f7060d00 task.ti=f706e000)
Stack:
 f5aa3c60 00000000 f706fe74 c107e7df 00000246 dea55380 00000054 f5aa3c60
 f706fe44 00000061 f70b4000 c13fff84 00000008 f706fe54 00000000 00000000
 00012f00 00012fff 00000028 c109e575 f6b36700 00100000 00000000 f706fe90
Call Trace:
 [<c107e7df>] unmap_mapping_range+0x7d/0x1e6
 [<c109e575>] ? mntput_no_expire+0x52/0xb6
 [<c11c12f6>] i915_gem_release_mmap+0x49/0x58
 [<c11c3449>] i915_gem_object_unbind+0x4c/0x125
 [<c11c353f>] i915_gem_free_object_tail+0x1d/0xdb
 [<c11c55a2>] i915_gem_free_object+0x3d/0x41
 [<c11a6be2>] ? drm_gem_object_free+0x0/0x27
 [<c11a6c07>] drm_gem_object_free+0x25/0x27
 [<c113c3ca>] kref_put+0x39/0x42
 [<c11c0a59>] drm_gem_object_unreference+0x16/0x18
 [<c11c0b15>] i915_gem_object_move_to_inactive+0xba/0xbe
 [<c11c0c87>] i915_gem_retire_requests_ring+0x16e/0x1a5
 [<c11c3645>] i915_gem_retire_requests+0x48/0x63
 [<c11c36ac>] i915_gem_retire_work_handler+0x4c/0x117
 [<c10385d1>] process_one_work+0x140/0x21b
 [<c103734c>] ? __need_more_worker+0x13/0x2a
 [<c10373b1>] ? need_to_create_worker+0x1c/0x35
 [<c11c3660>] ? i915_gem_retire_work_handler+0x0/0x117
 [<c1038faf>] worker_thread+0xd4/0x14b
 [<c1038edb>] ? worker_thread+0x0/0x14b
 [<c103be1b>] kthread+0x68/0x6d
 [<c103bdb3>] ? kthread+0x0/0x6d
 [<c12970f6>] kernel_thread_helper+0x6/0x10
Code: 00 e8 98 fe ff ff 5d c3 55 89 e5 3e 8d 74 26 00 ba 01 00 00 00 e8
84 fe ff ff 5d c3 55 89 e5 53 8d 64 24 fc 3e 8d 74 26 00 89 c3 <f0> ff
08 79 05 e8 ab ff ff ff 89 e0 25 00 e0 ff ff 89 43 10 58
EIP: [<c1295a20>] mutex_lock+0xf/0x27 SS:ESP 0068:f706fe18
CR2: 0000000000000054
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Keith Packard <keithp@keithp.com>

Detected by scripts/coccinelle/free/kfree.cocci.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Keith Packard <keithp@keithp.com>

We always skipped flushing the BLT ring if the request flush did not
include the RENDER domain. However, this neglects that we try to flush
the COMMAND domain after every batch and before the breadcrumb interrupt
(to make sure the batch is indeed completed prior to the interrupt
firing and so insuring CPU coherency). As a result of the missing flush,
incoherency did indeed creep in, most notable when using lots of command
buffers and so potentially rewritting an active command buffer (i.e.
the GPU was still executing from it even though the following interrupt
had already fired and the request/buffer retired).

As all ring->flush routines now have the same preconditions, de-duplicate
and move those checks up into i915_gem_flush_ring().

Fixes gem_linear_blit.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=35284Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Tested-by: mengmeng.meng@intel.com

Along the fast path for relocation handling, we attempt to copy directly
from the user data structures whilst holding our mutex. This causes
lockdep to warn about circular lock dependencies if we need to pagefault
the user pages. [Since when handling a page fault on a mmapped bo, we
need to acquire the struct mutex whilst already holding the mm
semaphore, it is then verboten to acquire the mm semaphore when already
holding the struct mutex. The likelihood of the user passing in the
relocations contained in a GTT mmaped bo is low, but conceivable for
extreme pathology.] In order to force the mm to return EFAULT rather
than handle the pagefault, we therefore need to disable pagefaults
across the relocation fast path.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Cc: Dave Airlie <airlied@linux.ie>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

Fix up the debug file to report the right frequencies.  On SNB, we program
the PCU with a frequency ratio, which is multiplied by 100MHz on the CPU
side.  But GFX only runs at half that, so report it as such to avoid
confusion.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Keith Packard <keithp@keithp.com>

The order of the calls does matter indeed.  Swapping the call order of
intel_dp_destroy() and intel_dp_encoder_destroy() fixes the problem.
This is because i2c_del_adapter unregisters the device which parent is
intel_connector, and connectors are removed in intel_dp_destroy().  Thus
intel_dp_encoder_destroy() must be called before intel_dp_destroy().

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=24822Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Keith Packard <keithp@keithp.com>

... even though it was disabled. A mistake in the handling of fence reuse
caused us to skip the vital delay of waiting for the object to finish
rendering before changing the register. This resulted in us changing the
fence register whilst the bo was active and so causing the blits to
complete using the wrong stride or even the wrong tiling. (Visually the
effect is that small blocks of the screen look like they have been
interlaced). The fix is to wait for the GPU to finish using the memory
region pointed to by the fence before changing it.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=34584
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
[Note for 2.6.38-stable, we need to reintroduce the interruptible passing]
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Tested-by: Dave Airlie <airlied@linux.ie>

A broken implementation of is_pot() prevented the detection of when a
singular pipe was enabled. Eric Anholt pointed out the existence of
is_power_of_2() so use that instead of our broken code!

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=35402Signed-off-by: Yuanhan Liu <yuanhan.liu@intel.com>
Tested-by: xunx.fang@intel.com
Reviewed-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

When i915_gem_retire_requests_ring calls i915_gem_request_remove_from_client,
the client_list for that request may already be removed in i915_gem_release.
So we may call twice list_del(&request->client_list), resulting in an
oops like this report:

[126167.230394] BUG: unable to handle kernel paging request at 00100104
[126167.230699] IP: [<f8c2ce44>] i915_gem_retire_requests_ring+0xd4/0x240 [i915]
[126167.231042] *pdpt = 00000000314c1001 *pde = 0000000000000000
[126167.231314] Oops: 0002 [#1] SMP
[126167.231471] last sysfs file: /sys/devices/LNXSYSTM:00/device:00/PNP0C0A:00/power_supply/BAT1/current_now
[126167.231901] Modules linked in: snd_seq_dummy nls_utf8 isofs btrfs zlib_deflate libcrc32c ufs qnx4 hfsplus hfs minix ntfs vfat msdos fat jfs xfs exportfs reiserfs cryptd aes_i586 aes_generic binfmt_misc vboxnetadp vboxnetflt vboxdrv parport_pc ppdev snd_hda_codec_hdmi snd_hda_codec_conexant snd_hda_intel snd_hda_codec snd_hwdep arc4 snd_pcm snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq uvcvideo videodev snd_timer snd_seq_device joydev iwlagn iwlcore mac80211 snd cfg80211 soundcore i915 drm_kms_helper snd_page_alloc psmouse drm serio_raw i2c_algo_bit video lp parport usbhid hid sky2 sdhci_pci ahci sdhci libahci
[126167.232018]
[126167.232018] Pid: 1101, comm: Xorg Not tainted 2.6.38-6-generic-pae #34-Ubuntu Gateway                          MC7833U /
[126167.232018] EIP: 0060:[<f8c2ce44>] EFLAGS: 00213246 CPU: 0
[126167.232018] EIP is at i915_gem_retire_requests_ring+0xd4/0x240 [i915]
[126167.232018] EAX: 00200200 EBX: f1ac25b0 ECX: 00000040 EDX: 00100100
[126167.232018] ESI: f1a2801c EDI: e87fc060 EBP: ef4d7dd8 ESP: ef4d7db0
[126167.232018]  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
[126167.232018] Process Xorg (pid: 1101, ti=ef4d6000 task=f1ba6500 task.ti=ef4d6000)
[126167.232018] Stack:
[126167.232018]  f1a28000 f1a2809c f1a28094 0058bd97 f1aa2400 f1a2801c 0058bd7b 0058bd85
[126167.232018]  f1a2801c f1a28000 ef4d7e38 f8c2e995 ef4d7e30 ef4d7e60 c14d1ebc f6b3a040
[126167.232018]  f1522cc0 000000db 00000000 f1ba6500 ffffffa1 00000000 00000001 f1a29214
[126167.232018] Call Trace:

Unfortunately the call trace reported was cut, but looking at debug
symbols the crash is at __list_del, when probably list_del is called
twice on the same request->client_list, as the dereferenced value is
LIST_POISON1 + 4, and by looking more at the debug symbols before
list_del call it should have being called by
i915_gem_request_remove_from_client

And as I can see in the code, it seems we indeed have the possibility
to remove a request->client_list twice, which would cause the above,
because we do list_del(&request->client_list) on both
i915_gem_request_remove_from_client and i915_gem_release

As Chris Wilson pointed out, it's indeed the case:
"(...) I had thought that the actual insertion/deletion was serialised
under the struct mutex and the intention of the spinlock was to protect
the unlocked list traversal during throttling. However, I missed that
i915_gem_release() is also called without struct mutex and so we do need
the double check for i915_gem_request_remove_from_client()."

This change does the required check to avoid the duplicate remove of
request->client_list.

Bugzilla: http://bugs.launchpad.net/bugs/733780
Cc: stable@kernel.org # 2.6.38
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

If the pipe or plane is already enabled, then we do not need to enable
it again and can skip the delay. Similarly if it is already disabled
when we want to disable it, we can also skip it.

This fixes a regression from b24e7179, which caused the LVDS
output on one PineView machine to become corrupt after changing
orientation several times.

References: https://bugs.freedesktop.org/show_bug.cgi?id=34601
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Keith Packard <keithp@keithp.com>
Tested-by: mengmeng.meng@intel.com

... as wait_for_vblank (and friends) will do a flush of the MMIO writes
anyway.

References: https://bugs.freedesktop.org/show_bug.cgi?id=34601
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>

Below is a patch against drm-next branch of 2.6.38-rc8+ kernel that adds
the capability to wait on vblank events for CRTCs that are greater than 1
and thus cannot be represented with primary/secondary flags in the legacy
interface. It was discussed on the dri-devel list in these two threads:

http://lists.freedesktop.org/archives/dri-devel/2011-March/009009.html
http://lists.freedesktop.org/archives/dri-devel/2011-March/009025.html

This patch extends the interface to drm_wait_vblank ioctl so that crtc>1
can be represented. It also adds a new capability to drm_getcap ioctl so
that the user space can check whether the new interface to drm_wait_vblank
is supported (and fall back to the legacy interface if not)
Signed-off-by: Ilija Hadzic <ihadzic@research.bell-labs.com>
Reviewed-by: Mario Kleiner <mario.kleiner at tuebingen.mpg.de>
Acked-by: Mario Kleiner <mario.kleiner at tuebingen.mpg.de>
Reviewed-by: Alex Deucher <alexdeucher@gmail.com>
Tested-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

As we may release the last reference, we need to store the device in a
local variable in order to unlock afterwards.

[   60.140768] BUG: unable to handle kernel paging request at 6b6b6b9f
[   60.140973] IP: [<c1536d11>] __mutex_unlock_slowpath+0x5a/0x111
[   60.141014] *pdpt = 0000000024a54001 *pde = 0000000000000000
[   60.141014] Oops: 0002 [#1] PREEMPT SMP
[   60.141014] last sysfs file: /sys/devices/LNXSYSTM:00/device:00/PNP0A08:00/PNP0C0A:00/power_supply/BAT0/voltage_now
[   60.141014] Modules linked in: uvcvideo ath9k pegasus ath9k_common ath9k_hw hid_egalax ath3k joydev asus_laptop sparse_keymap battery input_polldev
[   60.141014]
[   60.141014] Pid: 771, comm: meego-ux-daemon Not tainted 2.6.37.2-7.1 #1 EXOPC EXOPG06411/EXOPG06411
[   60.141014] EIP: 0060:[<c1536d11>] EFLAGS: 00010046 CPU: 0
[   60.141014] EIP is at __mutex_unlock_slowpath+0x5a/0x111
[   60.141014] EAX: 00000100 EBX: 6b6b6b9b ECX: e9b4a1b0 EDX: e4a4e580
[   60.141014] ESI: db162558 EDI: 00000246 EBP: e480be50 ESP: e480be44
[   60.141014]  DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
[   60.141014] Process meego-ux-daemon (pid: 771, ti=e480a000 task=e9b4a1b0 task.ti=e480a000)
[   60.141014] Stack:
[   60.141014]  e4a4e580 db162558 f5a2f838 e480be58 c1536dd0 e480be68 c125ab1b db162558
[   60.141014]  db1624e0 e480be78 c10ba071 db162558 f760241c e480be94 c10bb0bc 000155fe
[   60.141014]  f760241c f5a2f838 f5a2f8c8 00000000 e480bea4 c1037c24 00000000 f5a2f838
[   60.141014] Call Trace:
[   60.141014]  [<c1536dd0>] ? mutex_unlock+0x8/0xa
[   60.141014]  [<c125ab1b>] ? drm_gem_vm_close+0x39/0x3d
[   60.141014]  [<c10ba071>] ? remove_vma+0x2d/0x58
[   60.141014]  [<c10bb0bc>] ? exit_mmap+0x126/0x13f
[   60.141014]  [<c1037c24>] ? mmput+0x37/0x9a
[   60.141014]  [<c10d450d>] ? exec_mmap+0x178/0x19c
[   60.141014]  [<c1537f85>] ? _raw_spin_unlock+0x1d/0x36
[   60.141014]  [<c10d4eb0>] ? flush_old_exec+0x42/0x75
[   60.141014]  [<c1104442>] ? load_elf_binary+0x32a/0x922
[   60.141014]  [<c10d3f76>] ? search_binary_handler+0x200/0x2ea
[   60.141014]  [<c10d3ecf>] ? search_binary_handler+0x159/0x2ea
[   60.141014]  [<c1104118>] ? load_elf_binary+0x0/0x922
[   60.141014]  [<c10d56b2>] ? do_execve+0x1ff/0x2e6
[   60.141014]  [<c100970e>] ? sys_execve+0x2d/0x55
[   60.141014]  [<c1002a5a>] ? ptregs_execve+0x12/0x18
[   60.141014]  [<c10029dc>] ? sysenter_do_call+0x12/0x3c
[   60.141014]  [<c1530000>] ? init_centaur+0x9c/0x1ba
[   60.141014] Code: c1 00 75 0f ba 38 01 00 00 b8 8c 3a 6c c1 e8 cc 2e b0 ff 9c 58 8d 74 26 00 89 c7 fa 90 8d 74 26 00 e8 d2 b4 b2 ff b8 00 01 00 00 <f0> 66 0f c1 43 04 38 e0 74 07 f3 90 8a 43 04 eb f5 83 3d 64 ef
[   60.141014] EIP: [<c1536d11>] __mutex_unlock_slowpath+0x5a/0x111 SS:ESP 0068:e480be44
[   60.141014] CR2: 000000006b6b6b9f
Reported-by: Rusty Lynch <rusty.lynch@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

This was using old gem refcounting methods, fix it to be the same
as the normal create ioctl.
Signed-off-by: Dave Airlie <airlied@redhat.com>

Simplify the way the return value is set a number of times (mostly on
error).
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Merge list_del() + list_add_tail() to list_move_tail().
Signed-off-by: Nicolas Kaiser <nikai@nikai.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>

This commit changed an internal radeon structure, that meant a new driver
in -next had to be fixed up, merge in the commit and fix up the driver.

Also fixes a trivial nouveau merge.

Conflicts:
	drivers/gpu/drm/nouveau/nouveau_mem.c

Usually EDID retrieval is fine. However, sometimes, especially when the
machine is loaded, it fails, but succeeds after a few retries.

Based on a patch by Michael Buesch.
Reported-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Typo in the aspect scale setup.
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

As detect will use hw registers and may modify structures, it needs to be
serialised by use of the dev->mode_config.mutex. Make it so.

Otherwise, we may cause random crashes as the sysfs file is queried
whilst a concurrent hotplug poll is being run. For example:

[ 1189.189626] BUG: unable to handle kernel NULL pointer dereference at 00000100
[ 1189.189821] IP: [<e0c22019>] intel_tv_detect_type+0xa2/0x203 [i915]
[ 1189.190020] *pde = 00000000
[ 1189.190104] Oops: 0000 [#1] SMP
[ 1189.190209] last sysfs file: /sys/devices/pci0000:00/0000:00:02.0/drm/card0/card0-SVIDEO-1/status
[ 1189.190412] Modules linked in: mperf cpufreq_conservative cpufreq_userspace cpufreq_powersave cpufreq_stats decnet uinput fuse loop joydev snd_hd a_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_pcm_oss snd_mixer_oss snd_pcm i915 snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq drm_kms_helper snd_timer uvcvideo d rm snd_seq_device eeepc_laptop tpm_tis usbhid videodev i2c_algo_bit v4l1_compat snd sparse_keymap i2c_core hid serio_raw tpm psmouse evdev tpm_bios rfkill shpchp ac processor rng_c ore battery video power_supply soundcore pci_hotplug button output snd_page_alloc usb_storage uas ext3 jbd mbcache sd_mod crc_t10dif ata_generic ahci libahci ata_piix libata uhci_h cd ehci_hcd scsi_mod usbcore thermal atl2 thermal_sys nls_base [last unloaded: scsi_wait_scan]
[ 1189.192007]
[ 1189.192007] Pid: 1464, comm: upowerd Not tainted 2.6.37-2-686 #1 ASUSTeK Computer INC. 701/701
[ 1189.192007] EIP: 0060:[<e0c22019>] EFLAGS: 00010246 CPU: 0
[ 1189.192007] EIP is at intel_tv_detect_type+0xa2/0x203 [i915]
[ 1189.192007] EAX: 00000000 EBX: dca74000 ECX: e0f68004 EDX: 00068004
[ 1189.192007] ESI: dd110c00 EDI: 400c0c37 EBP: dca7429c ESP: de365e2c
[ 1189.192007]  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
[ 1189.192007] Process upowerd (pid: 1464, ti=de364000 task=dcc8acb0 task.ti=de364000)
[ 1189.192007] Stack: Mar 15 03:43:23 hostname kernel: [ 1189.192007]  e0c2cda4 70000000 400c0c30 00000000 dd111000 de365e54 de365f24 dd110c00
[ 1189.192007]  e0c22203 01000000 00000003 00000000 00000000 00000000 00000000 4353544e
[ 1189.192007]  30383420 00000069 00000000 00000000 00000000 00000000 00000000 00000000
[ 1189.192007] Call Trace: Mar 15 03:43:23 hostname kernel: [ 1189.192007]  [<e0c22203>] ?  intel_tv_detect+0x89/0x12d [i915]
[ 1189.192007]  [<e0a9dcef>] ?  status_show+0x0/0x2f [drm]
[ 1189.192007]  [<e0a9dd03>] ?  status_show+0x14/0x2f [drm]

[Digression: what is upowerd doing reading those power hungry files?]
Reported-by: Paul Menzel <paulepanter@users.sourceforge.net>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

* 'nouveau/drm-nouveau-next' of ../drm-nouveau-next:
  drm/nouveau: fix __nouveau_fence_wait performance
  drm/nv40: attempt to reserve just enough vram for all 32 channels
  drm/nv50: check for vm traps on every gr irq
  drm/nv50: decode vm faults some more
  drm/nouveau: add nouveau_enum_find() util function
  drm/nouveau: properly handle pushbuffer check failures
  drm/nvc0: remove vm hack forcing large/small pages to not share a PDE

Commit 21e86c1c ("drm/nouveau: remove
cpu_writers lock") turned on lazy waits. Unfortunately
__nouveau_fence_wait was not optimized for this case and on HZ=100
kernel wasted up to 10 ms per call.

Depending on application, it led to 10-30% FPS regression.

Fix it.
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Signed-off-by: Francisco Jerez <currojerez@riseup.net>

This also makes the fact we're giving 512MiB of GART space to all PCIE
boards explicit, although the vast majority (if not all) of them will
now have a ramin_rsvd_vram larger than 2MiB anyway.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

When "buffer in list" check does not pass, don't free validation lists - they were
not initialized yet.

Fixes this oops:

[drm] nouveau 0000:02:00.0: push 105 buffer not in list
BUG: unable to handle kernel NULL pointer dereference at 000000000000057c
IP: [<ffffffff81236aa4>] do_raw_spin_lock+0x14/0x13c
PGD 1ac6cb067 PUD 1aaa52067 PMD 0
CPU 0
Modules linked in: nouveau ttm drm_kms_helper snd_hda_codec_realtek snd_hda_intel snd_hda_codec

Pid: 6265, comm: OilRush_x86 Not tainted 2.6.38-rc6-nv+ #632 System manufacturer System Product Name/P6T SE
RIP: 0010:[<ffffffff81236aa4>]  [<ffffffff81236aa4>] do_raw_spin_lock+0x14/0x13c
(...)
Process OilRush_x86 (pid: 6265, threadinfo ffff8801a6aee000, task ffff8801a26c0000)
 0000000000000000 ffff8801ac74c618 0000000000000000 0000000000000578
 0000000000000000 ffff8801ac74c618 0000000000000000 ffff8801bd9d0000
 [<ffffffff81417f78>] _raw_spin_lock+0x1e/0x22
 [<ffffffffa00a2746>] nouveau_bo_fence+0x2e/0x60 [nouveau]
 [<ffffffffa00a540b>] validate_fini_list+0x35/0xeb [nouveau]
 [<ffffffffa00a54d3>] validate_fini+0x12/0x31 [nouveau]
 [<ffffffffa00a6386>] nouveau_gem_ioctl_pushbuf+0xe94/0xf6b [nouveau]
 [<ffffffff8141ac56>] ? sub_preempt_count+0x9e/0xb2
 [<ffffffff81417e94>] ? _raw_spin_unlock_irqrestore+0x30/0x4d
 [<ffffffff8105dea2>] ? __wake_up+0x3f/0x48
 [<ffffffff812aebb4>] drm_ioctl+0x289/0x361
 [<ffffffff8141ac56>] ? sub_preempt_count+0x9e/0xb2
 [<ffffffffa00a54f2>] ? nouveau_gem_ioctl_pushbuf+0x0/0xf6b [nouveau]
 [<ffffffff8141ac56>] ? sub_preempt_count+0x9e/0xb2
 [<ffffffffa010caa2>] nouveau_compat_ioctl+0x16/0x1c [nouveau]
 [<ffffffff81142c0d>] compat_sys_ioctl+0x1c8/0x12d7
 [<ffffffff814179ca>] ? trace_hardirqs_off_thunk+0x3a/0x6c
 [<ffffffff81058099>] sysenter_dispatch+0x7/0x30
 [<ffffffff8141798e>] ? trace_hardirqs_on_thunk+0x3a/0x3c
RIP  [<ffffffff81236aa4>] do_raw_spin_lock+0x14/0x13c
 RSP <ffff8801a6aefb88>
---[ end trace 0014d5d93e6147e1 ]---

Additionally, don't call validate_fini twice in case of validation failure.
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Signed-off-by: Maarten Maathuis <madman2003@gmail.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

Appears to be fixed with commit:

"drm/nv50-nvc0: make sure vma is definitely unmapped when destroying bo"
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

At least on my HP 2540p this is wrong at bootup, fine
at any other time once a lid event has occured. This is due to
_REG vs _INI ordering in the ACPI tables.
Signed-off-by: Dave Airlie <airlied@redhat.com>

* 'intel/drm-intel-next' of ../drm-next: (755 commits)
  drm/i915: Only wait on a pending flip if we intend to write to the buffer
  drm/i915/dp: Sanity check eDP existence
  drm/i915: Rebind the buffer if its alignment constraints changes with tiling
  drm/i915: Disable GPU semaphores by default
  drm/i915: Do not overflow the MMADDR write FIFO
  Revert "drm/i915: fix corruptions on i8xx due to relaxed fencing"
  drm/i915: Don't save/restore hardware status page address register
  drm/i915: don't store the reg value for HWS_PGA
  drm/i915: fix memory corruption with GM965 and >4GB RAM
  Linux 2.6.38-rc7
  Revert "TPM: Long default timeout fix"
  drm/i915: Re-enable GPU semaphores for SandyBridge mobile
  drm/i915: Replace vblank PM QoS with "Interrupt-Based AGPBUSY#"
  Revert "drm/i915: Use PM QoS to prevent C-State starvation of gen3 GPU"
  drm/i915: Allow relocation deltas outside of target bo
  drm/i915: Silence an innocuous compiler warning for an unused variable
  fs/block_dev.c: fix new kernel-doc warning
  ACPI: Fix build for CONFIG_NET unset
  mm: <asm-generic/pgtable.h> must include <linux/mm_types.h>
  x86: Use u32 instead of long to set reset vector back to 0
  ...

Conflicts:
	drivers/gpu/drm/i915/i915_gem.c

So we used to use lpfn directly to restrict VRAM when we couldn't
access the unmappable area, however this was removed in
93225b0d as it also restricted
the gtt placements. However it was only later noticed that this
broke on some hw.

This removes the active_vram_size, and just explicitly sets it
when it changes, TTM/drm_mm will always use the real_vram_size,
and the active vram size will change the TTM size used for lpfn
setting.

We should re-work the fpfn/lpfn to per-placement at some point
I suspect, but that is too late for this kernel.

Hopefully this addresses:
https://bugs.freedesktop.org/show_bug.cgi?id=35254

v2: fix reported useful VRAM size to userspace to be correct.
Signed-off-by: Dave Airlie <airlied@redhat.com>

We've been getting reports of complete system lockups with rv3xx hw on
AGP and PCIE when running gnome-shell or kwin with compositing.

It appears the hw really doesn't like setting these registers while
stuff is running, this moves the setting of the registers into the modeset
since they aren't required to be changed anywhere else.

fixes: https://bugs.freedesktop.org/show_bug.cgi?id=35183

Reported-and-tested-by: Álmos <aaalmosss@gmail.com
Signed-off-by: Dave Airlie <airlied@redhat.com>

Looks like these got passed over with both being merged at the same
time but not quite meeting in the middle.

should fix: https://bugs.freedesktop.org/show_bug.cgi?id=34137
along with Michael's phoronix article.

Reported-by: Chi-Thanh Christopher Nguyen
Article-written-by: Michael Larabel @ phoronix
Signed-off-by: Dave Airlie <airlied@redhat.com>

* 'media_fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6:
  [media] mantis_pci: remove asm/pgtable.h include
  [media] tda829x: fix regression in probe functions
  [media] mceusb: don't claim multifunction device non-IR parts
  [media] nuvoton-cir: fix wake from suspend
  [media] cx18: Add support for Hauppauge HVR-1600 models with s5h1411
  [media] ivtv: Fix corrective action taken upon DMA ERR interrupt to avoid hang
  [media] cx25840: fix probing of cx2583x chips
  [media] cx23885: Remove unused 'err:' labels to quiet compiler warning
  [media] cx23885: Revert "Check for slave nack on all transactions"
  [media] DiB7000M: add pid filtering
  [media] Fix sysfs rc protocol lookup for rc-5-sz
  [media] au0828: fix VBI handling when in V4L2 streaming mode
  [media] ir-raw: Properly initialize the IR event (BZ#27202)
  [media] s2255drv: firmware re-loading changes
  [media] Fix double free of video_device in mem2mem_testdev
  [media] DM04/QQBOX memcpy to const char fix