drm/i915: fix gen4 digital port hotplug definitions

Apparently Bspec is wrong in this case here even for gm45. Note that
Bspec is horribly misguided on i965g/gm, so we don't have any other
data points besides that it seems to make machines work better.

With this changes all the bits in PORT_HOTPLUG_STAT for the digital
ports are ordered the same way. This seems to agree with what register
dumps from the hpd storm handling code shows, where the LIVE bit and
the short/long pulse STATUS bits light up at the same time with this
enumeration (but no with the one from Bspec).

Also tested on my gm45 which has two DP+ ports, and everything seems
to still work as expected.

References: http://www.mail-archive.com/intel-gfx@lists.freedesktop.org/msg23054.html
Cc: Egbert Eich <eich@suse.com>
Cc: Jan Niggemann <jn@hz6.de>
Tested-by: Jan Niggemann <jn@hz6.de>
[danvet: Add a big warning that Bspec seems to be wrong for these
bits, suggested by Jani.]
Acked-by: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drm/i915: update last_vblank when disabling the power well

The DRM layer keeps track of our vblanks and it assumes our vblank
counters only go back to zero when they overflow. The problem is that
when we disable the power well our counters also go to zero, but it
doesn't mean they did overflow. So on this patch we grab the lock and
update last_vblank so the DRM layer won't think our counters
overflowed.

This patch fixes the following intel-gpu-tools test:
./kms_flip --run-subtest blocking-absolute-wf_vblank

Regression introduced by the following commit:

commit bf51d5e2cda5d36d98e4b46ac7fca9461e512c41
Author: Paulo Zanoni <paulo.r.zanoni@intel.com>
Date:   Wed Jul 3 17:12:13 2013 -0300
    drm/i915: switch disable_power_well default value to 1

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=66808
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
[danvet: Added a comment that this might be better done in
drm_vblank_post_modeset in general.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drm/i915: avoid brightness overflow when doing scale

Some card's max brightness level is pretty large, e.g. on Acer Aspire
4732Z, the max level is 989910. If user space set a large enough level
then the current scale done in intel_panel_set_backlight will cause an
integer overflow and the scaled level will be mistakenly small, leaving
user with an almost black screen. This patch fixes this problem.

Signed-off-by: Aaron Lu <aaron.lu@intel.com>
[danvet: Add a comment to explain what's going on.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drm/i915: Don't call encoder's get_config unless encoder is active

The SDVO code tries to compare the encoder's and crtc's idea of the
pixel_multiplier. Normally they have to match, but when transitioning
to DPMS off, we turn off the pipe before reading out the pipe_config,
so the pixel_multiplier in the pipe_config will be 0, whereas the
encoder will still have its pixel_multiplier set to whatever value we
were using when the display was active. This leads to a warning
from intel_modeset_check_state().

WARNING: CPU: 1 PID: 2846 at drivers/gpu/drm/i915/intel_sdvo.c:1378 intel_sdvo_get_config+0x158/0x160()
SDVO pixel multiplier mismatch, port: 0, encoder: 1
Modules linked in: snd_hda_codec_idt snd_hda_intel snd_hda_codec snd_hwdep
CPU: 1 PID: 2846 Comm: Xorg Not tainted 3.11.0-rc3-00208-gbe1e8d7-dirty #19
Hardware name: Apple Computer, Inc. Macmini1,1/Mac-F4208EC8, BIOS  MM11.88Z.0055.B03.0604071521 04/07/06
 00000000 00000000 ef0afa54 c1597bbb c1737ea4 ef0afa84 c10392ca c1737e6c
 ef0afab0 00000b1e c1737ea4 00000562 c12dfbe8 c12dfbe8 ef0afb14 00000000
 f697ec00 ef0afa9c c103936e 00000009 ef0afa94 c1737e6c ef0afab0 ef0afadc
Call Trace:
 [<c1597bbb>] dump_stack+0x41/0x56
 [<c10392ca>] warn_slowpath_common+0x7a/0xa0
 [<c103936e>] warn_slowpath_fmt+0x2e/0x30
 [<c12dfbe8>] intel_sdvo_get_config+0x158/0x160
 [<c12c3220>] check_crtc_state+0x1e0/0xb10
 [<c12cdc7d>] intel_modeset_check_state+0x29d/0x7c0
 [<c12dfe5c>] intel_sdvo_dpms+0x5c/0xa0
 [<c12985de>] drm_mode_obj_set_property_ioctl+0x40e/0x420
 [<c1298625>] drm_mode_connector_property_set_ioctl+0x35/0x40
 [<c1289294>] drm_ioctl+0x3e4/0x540
 [<c10fc1a2>] do_vfs_ioctl+0x72/0x570
 [<c10fc72f>] SyS_ioctl+0x8f/0xa0
 [<c159b7fa>] sysenter_do_call+0x12/0x22
---[ end trace 7ce940aff1366d60 ]---

Fix the problem by skipping the encoder get_config() function for
inactive encoders.

Tested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drm/i915: do not disable backlight on vgaswitcheroo switch off

On muxed systems, the other vgaswitcheroo client may depend on i915 to
handle the backlight. We began switching off the backlight since

commit a261b246ebd552fd5d5a8ed84cc931bb821c427f
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Thu Jul 26 19:21:47 2012 +0200

    drm/i915: disable all crtcs at suspend time

breaking backlight on discreet graphics in (some) muxed systems.

Keep the backlight on when the state is changed through vgaswitcheroo.

Note: The alternative would be to add a quirk table to achieve the same
based on system identifiers, but AFAICS it would asymptotically approach
effectively the same as this patch as more IDs are added, but with the
maintenance burden of the quirk table.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=55311
Tested-by: Fede <fedevx@yahoo.com>
Tested-by: Aximab <laurent.debian@gmail.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=59785
Tested-by: sfievet <sebastien.fievet@free.fr>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>