Commit Graph

294711 Commits

Author SHA1 Message Date
Jiri Kosina
3abee3526d Merge branches 'battery-scope', 'logitech' and 'multitouch' into for-linus 2012-03-20 13:04:25 +01:00
Laura Vasilescu
f1f996b66c kcore: fix spelling in read_kcore() comment
Signed-off-by: Laura Vasilescu <laura@rosedu.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-03-20 12:24:10 +01:00
Bob Peterson
220cca2a4f GFS2: Change truncate page allocation to be GFP_NOFS
This patch changes the page allocation in gfs2_block_truncate_page
and two others to GFP_NOFS to avoid deadlock in low-memory conditions.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-03-20 11:05:00 +00:00
Carsten Emde
da0df92b57 drm: allow loading an EDID as firmware to override broken monitor
Broken monitors and/or broken graphic boards may send erroneous or no
EDID data. This also applies to broken KVM devices that are unable to
correctly forward the EDID data of the connected monitor but invent
their own fantasy data.

This patch allows to specify an EDID data set to be used instead of
probing the monitor for it. It contains built-in data sets of frequently
used screen resolutions. In addition, a particular EDID data set may be
provided in the /lib/firmware directory and loaded via the firmware
interface. The name is passed to the kernel as module parameter of the
drm_kms_helper module either when loaded
  options drm_kms_helper edid_firmware=edid/1280x1024.bin
or as kernel commandline parameter
  drm_kms_helper.edid_firmware=edid/1280x1024.bin

It is also possible to restrict the usage of a specified EDID data set
to a particular connector. This is done by prepending the name of the
connector to the name of the EDID data set using the syntax
  edid_firmware=[<connector>:]<edid>
such as, for example,
  edid_firmware=DVI-I-1:edid/1920x1080.bin
in which case no other connector will be affected.

The built-in data sets are
Resolution    Name
--------------------------------
1024x768      edid/1024x768.bin
1280x1024     edid/1280x1024.bin
1680x1050     edid/1680x1050.bin
1920x1080     edid/1920x1080.bin

They are ignored, if a file with the same name is available in the
/lib/firmware directory.

The built-in EDID data sets are based on standard timings that may not
apply to a particular monitor and even crash it. Ideally, EDID data of
the connected monitor should be used. They may be obtained through the
drm/cardX/cardX-<connector>/edid entry in the /sys/devices PCI directory
of a correctly working graphics adapter.

It is even possible to specify the name of an EDID data set on-the-fly
via the /sys/module interface, e.g.
echo edid/myedid.bin >/sys/module/drm_kms_helper/parameters/edid_firmware
The new screen mode is considered when the related kernel function is
called for the first time after the change. Such calls are made when the
X server is started or when the display settings dialog is opened in an
already running X server.

Signed-off-by: Carsten Emde <C.Emde@osadl.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 10:09:28 +00:00
Seung-Woo Kim
3e148baf46 drm/exynos: enable hdmi audio feature
This patch adds hdmi audio feature for exynos drm.
With this patch, i2s channel feeds audio data in hdmi when hdmi is connected.

Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 09:41:46 +00:00
Eunchul Kim
ba3849d56b drm/exynos: add default pixel format for plane
DRM checks whether the plane supports a pixel format of fb when plane is
updated. This adds a default pixel format supporting format exynos drm
plane.

Signed-off-by: Eunchul Kim <chulspro.kim@samsung.com>
Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 09:41:46 +00:00
Joonyoung Shim
590f418a5c drm/exynos: cleanup exynos_hdmi.h
The some contents of the exynos_hdmi.h are used only in exynos_hdmi.c,
so move them to exynos_hdmi.c.

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 09:41:45 +00:00
Joonyoung Shim
a31f6ecf35 drm/exynos: add is_local member in exynos_drm_subdrv struct
The is_local member indicates unused subdrv such connector and encoder
so doesn't make resources for them.

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 09:40:25 +00:00
Joonyoung Shim
9084f7b8a5 drm/exynos: add subdrv open/close functions
Some subdrv need open and close functions call when open and close drm.

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 09:40:24 +00:00
Joonyoung Shim
132a5b915f drm/exynos: remove module of exynos drm subdrv
The exynos drm driver has several subdrv. They each can be module but it
causes unfixed probe order of exynodr drm driver and each subdrv. It
also needs some weird codes such as exynos_drm_fbdev_reinit and
exynos_drm_mode_group_reinit. This patch can remove weird codes and
clear codes through we doesn't modularity each subdrv.

Also this removes unnecessary codes related module.

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 09:40:23 +00:00
Joonyoung Shim
3ab09435d5 drm/exynos: release pending pageflip events when closed
We should release pending pageflip events when closed. If not, they will
be dangling events.

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 09:40:23 +00:00
Inki Dae
f0b1bda725 drm/exynos: added new funtion to get/put dma address.
this function would be used for drm based 2d acceleration driver
to get/put dma address through gem handle.
when exynos_drm_get_dma_address is called reference count of
gem object would be increased not to be released by gem close and
when exynos_drm_put_dma_address is called the reference count of
this gem object would be decreased to be released.

Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 09:40:22 +00:00
Inki Dae
2b35892e9d drm/exynos: update gem and buffer framework.
with this patch, we can allocate physically continuous or non-continuous
memory and also it creates scatterlist for iommu support so allocated
memory region can be mapped to iommu page table using scatterlist.

Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 09:40:21 +00:00
Inki Dae
1de425b0bd drm/exynos: added mode_fixup feature and code clean.
this patch adds mode_fixup feature for hdmi module that
specific driver changes current mode to driver desired mode
properly.

Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 09:40:21 +00:00
Joonyoung Shim
3ecd70b18c drm/exynos: add HDMI version 1.4 support
Later Exynos series from Exynos4X12 support HDMI version 1.4. We will
distinguish to use which version via platform data. This patch supports
only default features of HDMI version 1.4(The 3D, sound and etc don't
support yet)

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 09:40:20 +00:00
Gao feng
1f85851e17 ipv6: fix incorrent ipv6 ipsec packet fragment
Since commit 299b0767(ipv6: Fix IPsec slowpath fragmentation problem)
In func ip6_append_data,after call skb_put(skb, fraglen + dst_exthdrlen)
the skb->len contains dst_exthdrlen,and we don't reduce dst_exthdrlen at last
This will make fraggap>0 in next "while cycle",and cause the size of skb incorrent

Fix this by reserve headroom for dst_exthdrlen.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-20 05:39:34 -04:00
Joonyoung Shim
22b21ae6b8 drm/exynos: remove exynos_mixer.h
The contents of exynos_mixer.h are used only in exynos_mixer.c, so
separated header is unnecessary.

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 09:35:37 +00:00
Yoichi Yuasa
1278f7de7f gma500: Fix mmap frambuffer
It cannot map correctly if page fault begins from a intermediate address.

[The driver prefaults the mapping, so we need to work from the correct
 base address not the faulting address otherwise the map appears offset by
 the fault offset]

Signed-off-by: Yoichi Yuasa <yuasa@linux-mips.org>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 09:31:12 +00:00
Dave Airlie
de49442f59 Merge tag 'drm-intel-next-2012-03-01' of git://people.freedesktop.org/~danvet/drm-intel into drm-next
* tag 'drm-intel-next-2012-03-01' of git://people.freedesktop.org/~danvet/drm-intel:
  drm/i915: Only clear the GPU domains upon a successful finish
  drm/i915: reenable gmbus on gen3+ again
  drm/i915: i2c: unconditionally set up gpio fallback
  drm/i915: merge gmbus and gpio i2c adpater into one
  drm/i915: merge struct intel_gpio into struct intel_gmbus
  i2c: export bit-banging algo functions
  drm/nouveau: do a better job at hiding the NIH i2c bit-banging algo
  drm/i915: add dev_priv to intel_gmbus
  drm/i915: Fix single msg gmbus_xfers writes
  drm/i915: error_buffer->ring should be signed
  drm/i915: Silence the error message from i915_wait_request()
  drm/i915: use the new hdmi_force_audio enum more
  drm/i915: No need to search again after retiring requests
  drm/i915: Only bump refcnt on objects scheduled for eviction
  drm/i915/bios: Downgrade the "signature missing" DRM_ERROR to debug
  drm/i915: Ignore LVDS on hp t5745 and hp st5747 thin client
  drm/i915: Fixes distorted external screen image on HP 2730p
2012-03-20 08:51:37 +00:00
Florian Tobias Schandinat
e9fe8a714e Merge branch 'for-3.4' of git://gitorious.org/linux-omap-dss2/linux into fbdev-next 2012-03-20 08:49:51 +00:00
Michel Dänzer
654c59cf76 drm/radeon: Drop radeon_gem_object_(un)pin.
Only radeon_gem_object_unpin was used anymore, in only one place.

Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 08:47:50 +00:00
Michel Dänzer
0349af70da drm/radeon: Restrict offset for legacy display engine.
The hardware only takes 27 bits for the offset, so larger offsets are
truncated, and the display shows random bits other than the intended ones.

Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 08:47:46 +00:00
Michel Dänzer
c4353016da drm/radeon: Restrict offset for legacy hardware cursor.
The hardware only takes 27 bits for the offset, so larger offsets are
truncated, and the hardware cursor shows random bits other than the intended
ones.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=46796

Cc: stable@vger.kernel.org
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 08:47:41 +00:00
Tvrtko Ursulin
11fe126625 drm/radeon/kms: reduce probe latency on digital connectors
On a system with one HDMI and one VGA connector the latter
causes output polling to run every ten seconds. This causes
full EDID re-fetch on every poll and approx. 100ms rendering
stalls are experienced by full screen page-flipping applications.
Optimisation is to trust HPD sense on R600+ ASICs and to skip
doing these expensive probes unless HPD sense has changed.

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=47007

agd5f: fix patch and message formatting.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@onelan.co.uk>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 08:45:42 +00:00
Alex Deucher
4c1b2d2da3 drm/radeon/kms: add connector quirk for Fujitsu D3003-S2 board
vbios lists DVI-I port as VGA and DVI-D.

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=47007

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 08:45:40 +00:00
Alex Deucher
e00e8b5e76 drm/radeon/kms: fix analog load detection on DVI-I connectors
We digital encoders have a detect function as well (for
DP to VGA bridges), so we make sure we choose the analog
one here.

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=47007

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 08:45:39 +00:00
Joe Perches
25d0479a59 drm/ttm: Use pr_fmt and pr_<level>
Use the more current logging style.

Add pr_fmt and remove the TTM_PFX uses.
Coalesce formats and align arguments.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 08:45:35 +00:00
Julia Lawall
f10487658a drivers/gpu/drm/savage/savage_state.c: add missing kfree
Most of the error handling code in this function frees the buffers
kcmd_addr, kvb_addr, and kbox_addr allocated at the beginning of this
function.  These two branches are changed to do the same.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 08:45:31 +00:00
Julia Lawall
f48bb04a56 drivers/gpu/drm/radeon/radeon_cs.c: eliminate possible double free
The function radeon_cs_parser_init is only called from two places, in
drivers/gpu/drm/radeon/radeon_cs.c and drivers/gpu/drm/radeon/r600_cs.c.
In each case, if the call fails another function is called that frees all
of the kdata and dpage information in the chunks array.  So this
information should not be freed in radeon_cs_parser_init as well.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 08:45:27 +00:00
Dave Airlie
abc8113fe5 drm/radeon: dp only enable enhanced framing if sink supports.
DisplayPort spec v1.1a, Table 2-52.

Same commit to Intel by ajax in 9962c9252e

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 08:45:01 +00:00
Marek Olšák
3c12513d2f drm/radeon/kms: skip db/cb/streamout checking when possible on r600
Signed-off-by: Marek Olšák <maraeo@gmail.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 08:44:53 +00:00
Marek Olšák
6333003be6 drm/radeon/kms: compute GPU addresses correctly on r600
Signed-off-by: Marek Olšák <maraeo@gmail.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 08:44:49 +00:00
Marek Olšák
747e42a102 drm/radeon/kms: remove some unused variables in evergreen_cs_track
and document the other unused ones.

Signed-off-by: Marek Olšák <maraeo@gmail.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 08:44:45 +00:00
Marek Olšák
308385782d drm/radeon/kms: skip db/cb/streamout checking when possible on evergreen
Signed-off-by: Marek Olšák <maraeo@gmail.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 08:44:40 +00:00
Marek Olšák
7e9fa5f69f drm/radeon/kms: optimize streamout checking for evergreen
Signed-off-by: Marek Olšák <maraeo@gmail.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 08:44:35 +00:00
Marek Olšák
7885713138 drm/radeon/kms: compute GPU addresses correctly on evergreen
There are also two fixes:
- In DRAW_INDEX_2, we read idx_value, but should have read idx+1.
- When correcting SQ_VTX_CONSTANT_WORD1_0.SIZE, we should subtract
  the offset.

Signed-off-by: Marek Olšák <maraeo@gmail.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 08:44:29 +00:00
Marek Olšák
7df7c547c5 drm/radeon/kms: make some DRM errors more informative
Signed-off-by: Marek Olšák <maraeo@gmail.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 08:44:23 +00:00
Marek Olšák
779923bc40 drm/radeon/kms: skip cb/db checking if SX_MISC is 1 on r600+
Signed-off-by: Marek Olšák <maraeo@gmail.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 08:44:12 +00:00
Dave Airlie
9c1dfc5574 drm/usb: move usb support into a separate module
In order to satisfy all the various Kconfig options between
USB and DRM, we need to split the USB code out into a separate module
and export symbols to it.

This fixes build problems in -next reported by sfr.

Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-03-20 06:59:29 +00:00
David S. Miller
5c473ed26d cpsw: Hook up default ndo_change_mtu.
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-20 00:33:59 -04:00
James Morris
09f61cdbb3 Merge branch 'for-security' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor into next 2012-03-20 12:52:17 +11:00
Tetsuo Handa
7e570145cb AppArmor: Fix location of const qualifier on generated string tables
Signed-off-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2012-03-19 18:22:46 -07:00
Tetsuo Handa
7d7473dbdb TOMOYO: Return error if fails to delete a domain
Call sequence:
tomoyo_write_domain() --> tomoyo_delete_domain()

In 'tomoyo_delete_domain', return -EINTR if locking attempt is
interrupted by signal.

At present it returns success to its caller 'tomoyo_write_domain()'
even though domain is not deleted. 'tomoyo_write_domain()' assumes
domain is deleted and returns success to its caller. This is wrong behaviour.

'tomoyo_write_domain' should return error from tomoyo_delete_domain() to its
caller.

Signed-off-by: Santosh Nayak <santoshprasadnayak@gmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2012-03-20 12:06:50 +11:00
Linus Torvalds
5ed59af850 Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core/locking changes for v3.4 from Ingo Molnar

* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Simplify return logic
  futex: Cover all PI opcodes with cmpxchg enabled check
2012-03-19 17:11:15 -07:00
Linus Torvalds
b7f077d7bc Merge branch 'core-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core/iommu changes for v3.4 from Ingo Molnar

* 'core-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/iommu/intel: Increase the number of iommus supported to MAX_IO_APICS
  x86/iommu/intel: Fix identity mapping for sandy bridge
2012-03-19 17:10:38 -07:00
Dmitry Torokhov
10ce3cc919 Merge branch 'next' into for-linus 2012-03-19 17:02:01 -07:00
Linus Torvalds
b0e37d7ac6 Merge branch 'dcache-word-accesses'
* branch 'dcache-word-accesses':
  vfs: use 'unsigned long' accesses for dcache name comparison and hashing

This does the name hashing and lookup using word-sized accesses when
that is efficient, namely on x86 (although any little-endian machine
with good unaligned accesses would do).

It does very much depend on little-endian logic, but it's a very hot
couple of functions under some real loads, and this patch improves the
performance of __d_lookup_rcu() and link_path_walk() by up to about 30%.
Giving a 10% improvement on some very pathname-heavy benchmarks.

Because we do make unaligned accesses past the filename, the
optimization is disabled when CONFIG_DEBUG_PAGEALLOC is active, and we
effectively depend on the fact that on x86 we don't really ever have the
last page of usable RAM followed immediately by any IO memory (due to
ACPI tables, BIOS buffer areas etc).

Some of the bit operations we do are a bit "subtle".  It's commented,
but you do need to really think about the code.  Or just consider it
black magic.

Thanks to people on G+ for some of the optimized bit tricks.
2012-03-19 16:37:28 -07:00
Al Viro
bf362f750b constify struct pci_dev * in obvious cases
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-03-20 00:20:37 +01:00
Linus Torvalds
6d7d1a0dc7 vfs: get rid of batshit-insane pointless dentry hash calculations
For some odd historical reason, the final mixing round for the dentry
cache hash table lookup had an insane "xor with big constant" logic.  In
two places.

The big constant that is being xor'ed is GOLDEN_RATIO_PRIME, which is a
fairly random-looking number that is designed to be *multiplied* with so
that the bits get spread out over a whole long-word.

But xor'ing with it is insane.  It doesn't really even change the hash -
it really only shifts the hash around in the hash table.  To make
matters worse, the insane big constant is different on 32-bit and 64-bit
builds, even though the name hash bits we use are always 32-bit (and the
bits from the pointer we mix in effectively are too).

It's all total voodoo programming, in other words.

Now, some testing and analysis of the hash chains shows that the rest of
the hash function seems to be fairly good.  It does pick the right bits
of the parent dentry pointer, for example, and while it's generally a
bad idea to use an xor to mix down the upper bits (because if there is a
repeating pattern, the xor can cause "destructive interference"), it
seems to not have been a disaster.

For example, replacing the hash with the normal "hash_long()" code (that
uses the GOLDEN_RATIO_PRIME constant correctly, btw) actually just makes
the hash worse.  The hand-picked hash knew which bits of the pointer had
the highest entropy, and hash_long() ends up mixing bits less optimally
at least in some trivial tests.

So the hash function overall seems fine, it just has that really odd
"shift result around by a constant xor".

So get rid of the silly xor, and replace the down-mixing of the bits
with an add instead of an xor that tends to not have the same kind of
destructive interference issues.  Some stats on the resulting hash
chains shows that they look statistically identical before and after,
but the code is simpler and no longer makes you go "WTF?".

Also, the incoming hash really is just "unsigned int", not a long, and
there's no real point to worry about the high 26 bits of the dentry
pointer for the 64-bit case, because they are all going to be identical
anyway.

So also change the hashing to be done in the more natural 'unsigned int'
that is the real size of the actual hashed data anyway.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-19 16:19:53 -07:00
Anatolij Gustschin
f413070e3f fbdev: da8xx: add support for SP10Q010 display
Add timing data for Hitachi SP10Q010 display and allow configuration
of the 4bpp palette. For 4bpp framebuffer enable reversed order of
pixels in a byte. This requires defining FB_CFB_REV_PIXELS_IN_BYTE
and additionally setting var.nonstd to the value FB_NONSTD_REV_PIX_IN_B.
Note that it is not enough to set da8xx_fb_var.nonstd to this value
statically, since FBIOPUT_VSCREENINFO ioctl might pass var struct with
.nonstd field set to zero or another value. Therefore this setting must
be adjusted in fb_check_var() according to the requested bpp value.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Cc: Manjunathappa, Prakash <prakash.pm@ti.com>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
2012-03-19 22:59:47 +00:00