Ted Ts'o reports that his Lenovo T540p ThinkPad crashes at boot if
attached to the docking station.  This is a regression that he was able
to bisect to commit 8c7b5ccb7298: "drm/i915: Use atomic helpers for
computing changed flags:"

The reason seems to be the new call to drm_atomic_helper_check_modeset()
added to intel_modeset_compute_config(), which in turn calls
update_connector_routing(), and somehow ends up picking a NULL crtc for
the connector state, causing the subsequent drm_crtc_index() to OOPS.

Daniel Vetter says that the fundamental issue seems to be confusion in
the encoder selection, and this isn't the right fix, but while he chases
down the proper fix, this at least avoids the NULL pointer dereference
and makes Ted's docking station work again.

Reported-bisected-and-tested-by: Theodore Ts'o <tytso@mit.edu>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Mani Nikula <jani.nikula@linux.intel.com>
Cc: Dave Airlie <airlied@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull drm intel fixes from Daniel Vetter:
 "I delayed my -fixes pull a bit hoping that I could include a fix for
  the dp mst stuff but looks a bit more nasty than that.  So just 3
  other regression fixes, one 4.2 other two cc: stable"

* tag 'drm-intel-fixes-2015-07-31' of git://anongit.freedesktop.org/drm-intel:
  drm/i915: Declare the swizzling unknown for L-shaped configurations
  drm/i915: Mark PIN_USER binding as GLOBAL_BIND without the aliasing ppgtt
  drm/i915: Replace WARN inside I915_READ64_2x32 with retry loop

The old style of memory interleaving swizzled upto the end of the
first even bank of memory, and then used the remainder as unswizzled on
the unpaired bank - i.e. swizzling is not constant for all memory. This
causes problems when we try to migrate memory and so the kernel prevents
migration at all when we detect L-shaped inconsistent swizzling.
However, this issue also extends to userspace who try to manually detile
into memory as the swizzling for an individual page is unknown (it
depends on its physical address only known to the kernel), userspace
cannot correctly swizzle.

Note that this is a new attempt for the previously merged one,
reverted in

commit d82c0ba6e306f079407f07003e53c262d683397b
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Tue Jul 14 12:29:27 2015 +0200

    Revert "drm/i915: Declare the swizzling unknown for L-shaped configurations"

This is cc: stable since we need it to fix up troubles with wc cpu
mmaps that userspace recently started to use widely.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91105
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: stable@vger.kernel.org
[danvet: Add note about previous (failed attempt).]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

If the device does not support the aliasing ppgtt, we must translate
user bind requests (PIN_USER) from LOCAL_BIND to a GLOBAL_BIND. However,
since this is device specific we cannot do this conveniently in the
upper layers and so must manage the vma->bound flags in the backend.

Partial revert of commit 75d04a3773ecee617847de963ae4195d6aa74c28 [4.2-rc1]
Author: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Date:   Tue Apr 28 17:56:17 2015 +0300

    drm/i915/gtt: Allocate va range only if vma is not bound

Note this was spotted by Daniel originally, but we dropped the ball in
getting the fix in before the bug going wild. Sorry all.

Reported-by: Vincent Legoll vincent.legoll@gmail.com
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91133
References: https://bugs.freedesktop.org/show_bug.cgi?id=90224
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michel Thierry <michel.thierry@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Fix for nasty crash on mdp4 in disable path, fix for dma-buf export,
smb leak on mdp5 which could result in intermittent modeset fails, and
don't let interrupted system call disturb atomic commit once we are
past the point of no return.

* 'msm-fixes-4.2' of git://people.freedesktop.org/~robclark/linux:
  drm/msm/mdp5: release SMB (shared memory blocks) in various cases
  drm/msm: change to uninterruptible wait in atomic commit
  drm/msm: mdp4: Fix drm_framebuffer dereference crash
  drm/msm: fix msm_gem_prime_get_sg_table()

Release all blocks after the pipe is disabled, even when vsync
didn't happen in some error cases. Allow requesting SMB multiple
times before configuring to hardware, by releasing blocks not
programmed to hardware yet for shrinking case.

This fixes a potential leak of shared memory pool blocks.

Signed-off-by: Wentao Xu <wentaox@codeaurora.org>
Tested-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>

The atomic commit cannot easily undo and return an error once the
state is swapped. Change to uninterruptible wait, and ignore the
timeout error.

Signed-off-by: Wentao Xu <wentaox@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>

mdp4_get_frame_format() can dereference a drm_framebuffer when it's NULL.
Call it in mdp4_plane_mode_set only when we know fb is non-NULL.

Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>

We need to return a new sgt, since the caller takes ownership of it.

Reported-by: Stanimir Varbanov <svarbanov@mm-sol.com>
Signed-off-by: Rob Clark <robdclark@gmail.com>

Signed-off-by: monk.liu <monk.liu@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>