We found a new codec ID 292, and that just a simple quirk would enable
sound output/input on this ALC292 chip.
BugLink: https://bugs.launchpad.net/bugs/1081466
Cc: stable@vger.kernel.org
Tested-by: Acelan Kao <acelan.kao@canonical.com>
Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
While these got added in the right place everywhere else, entry_64.S
is the odd one where they ended up before the initial CFI directive(s).
In order to cover the full code ranges, the CFI directive must be
first, though.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/5093BA1F02000078000A600E@nat28.tlf.novell.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Add valid patch size for family 16h processors.
[ hpa: promoting to urgent/stable since it is hw enabling and trivial ]
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@amd.com>
Acked-by: Andreas Herrmann <herrmann.der.user@googlemail.com>
Link: http://lkml.kernel.org/r/1353004910-2204-1-git-send-email-boris.ostrovsky@amd.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org>
Modules, in particular oprofile (and possibly other similar tools)
need kernel_stack_pointer(), so export it using EXPORT_SYMBOL_GPL().
Cc: Yang Wei <wei.yang@windriver.com>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Jun Zhang <jun.zhang@intel.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20120912135059.GZ8285@erda.amd.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
The biggest batch of fixes here is the Kirkwood DMA fixes, plus a couple
of other small fixes.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.12 (GNU/Linux)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=V7+d
-----END PGP SIGNATURE-----
Merge tag 'asoc-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus
ASoC: Fixes for v3.7
The biggest batch of fixes here is the Kirkwood DMA fixes, plus a couple
of other small fixes.
Pull missed powerpc fixes from Benjamin Herrenschmidt:
"Here are small 52xx fixes that Anatolij asked me to pull a while back
and that I completely missed. The stuff is local to that platform
code, and was in next for a while, so it should still go into 3.7."
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
powerpc/mpc5200: move lpbfifo node and fix its interrupt property
powerpc: 52xx: nop out unsupported critical IRQs
powerpc/pcm030: add pcm030-audio-fabric to dts
Pull KVM maintainership update from Avi Kivity:
"After many years of maintaining KVM, I am moving on. It was a real
pleasure for me to work with so many talented and dedicated hackers on
this project.
Replacing me will be one of those talented and dedicated hackers,
Gleb, who has authored hundreds of patches in and around KVM."
* git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: taking co-maintenance
KVM: Retire as maintainer
Some fixes and a MAINTAINERS update to remove my lost AMD email address
from the file. The fixes take care of a resource leak and a problem on
VT-d with the new IOMMU group code.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.11 (GNU/Linux)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=RZ+1
-----END PGP SIGNATURE-----
Merge tag 'iommu-fixes-v3.7-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu
Pull IOMMU fixes from Joerg Roedel:
"Some fixes and a MAINTAINERS update to remove my lost AMD email
address from the file. The fixes take care of a resource leak and a
problem on VT-d with the new IOMMU group code."
* tag 'iommu-fixes-v3.7-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
intel-iommu: Fix lookup in add device
iommu/tegra-smmu.c: fix dentry reference leak in smmu_debugfs_stats_show().
iommu/amd: Update MAINTAINERS entry
Pull reiserfs and ext3 fixes from Jan Kara:
"Fixes of reiserfs deadlocks when quotas are enabled (locking there was
completely busted by BKL conversion) and also one small ext3 fix in
the trim interface."
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
ext3: Avoid underflow of in ext3_trim_fs()
reiserfs: Move quota calls out of write lock
reiserfs: Protect reiserfs_quota_write() with write lock
reiserfs: Protect reiserfs_quota_on() with write lock
reiserfs: Fix lock ordering during remount
This is a regression introduced by ceb90fa0 (xen/privcmd: add
PRIVCMD_MMAPBATCH_V2 ioctl). It broke xentrace as it used
xc_map_foreign() instead of xc_map_foreign_bulk().
Most code-paths prefer the MMAPBATCH_V2, so this wasn't very obvious
that it broke. The return value is set early on to -EINVAL, and if all
goes well, the "set top bits of the MFN's" never gets called, so the
return value is still EINVAL when the function gets to the end, causing
the caller to think it went wrong (which it didn't!)
Now also including Andres "move the ret = -EINVAL into the error handling
path, as this avoids other similar errors in future.
Signed-off-by: Mats Petersson <mats.petersson@citrix.com>
Acked-by: Andres Lagar-Cavilla <andres@lagarcavilla.org>
Acked-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Anatolij 52xx updates:
Patch for pcm030 device tree fixing the probe() in pcm030-audio-fabric
driver. Changes to this driver have been merged in 3.7-rc1 via ASoC
tree, but this required device tree patch was submitted separately to
the linux-ppc list and is still missing in mainline. Without this patch
the probe() in pcm030-audio-fabric driver wrongly returns -ENODEV.
A patch from Wolfram fixing wrong invalid critical irq warnings for
all mpc5200 boards.
Another patch for all mpc5200 device trees fixing wrong L1 cell in
the LPB FIFO interrupt property and moving the LPB FIFO node to the
common mpc5200b.dtsi file so that this common node will be present
in all mpc5200 device trees.
Don't even momentarily set the pause status when starting the channel;
if we do, we should check the busy bit to ensure that we comply with
the spec. In any case, it isn't necessary; we will not active on a
START event so there is no need to pause the DMA.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Stress testing the driver with multiple start/stop events causes
kirkwood-dma to report underrun errors (which used to cause the kernel
to lock up solidly). This is because kirkwood-i2s is not respecting
the restrictions imposed on clearing the 'pause' bit. Follow what the
spec says; the busy bit must be read as being clear twice before the
pause bit can be released. This solves the underruns.
However, it has been noticed that the busy bit occasionally does not
clear itself, hence the waiting is bounded to 5ms maximum to avoid a
new reason for the kernel to lockup.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
This is part of a patch found in Rabeeh Khoury's git tree for the
cubox, which is further attributed to Sebastian Hesselbrath.
Rather than masking the KIRKWOOD_DCO_SPCR_STATUS register contents
against the registers virtual address, let's actually use the bit
definition for the locked status, as required in the documentation.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Ignoring the real cause of the interrupt is not a good idea; this
behaviour has been observed to bring Dove platforms to silently
lockup. Instead, on error fall through to the normal interrupt
processing.
This is especially important on Dove platforms as errors are
handled separately, and allows us to clear down the real cause of
the interrupt.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
This is part of a patch found in Rabeeh Khoury's git tree for the
cubox.
You can not use virt_to_phys() on the address returned from
dma_alloc_coherent(); it may not be part of the kernel direct-mapped
memory. Fix this to use the DMA address instead.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Add a resource-private header for common resource definitions
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Refactor resource management to make it easy to hook up resources
that are backed up by buffers. In particular, resources and their
backing buffers can be evicted and rebound, if supported by the device.
To avoid query deadlocks, the query code is also modified somewhat.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Building for Athlon/Duron/K7 results in the following build error,
arch/x86/boot/compressed/eboot.o: In function `__constant_memcpy3d':
eboot.c:(.text+0x385): undefined reference to `_mmx_memcpy'
arch/x86/boot/compressed/eboot.o: In function `efi_main':
eboot.c:(.text+0x1a22): undefined reference to `_mmx_memcpy'
because the boot stub code doesn't link with the kernel proper, and
therefore doesn't have access to the 3DNow version of memcpy. So,
follow the example of misc.c and #undef memcpy so that we use the
version provided by misc.c.
See https://bugzilla.kernel.org/show_bug.cgi?id=50391
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Reported-by: Ryan Underwood <nemesis@icequake.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: stable@vger.kernel.org
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Commit 71c6c837 (drivers/net: fix tasklet misuse issue) introduced a
build failure in the xilinx driver. axienet_dma_err_handler isn't
declared before its use in axienet_open.
This patch provides the prototype before axienet_open.
Cc: Xiaotian Feng <dannyfeng@tencent.com>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 2e064b1 (x86, efi: Fix issue of overlapping .reloc section for
EFI_STUB) removed a dummy reloc added by commit 291f363 (x86, efi: EFI
boot stub support), but forgot to remove the dummy long used by that
reloc.
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Tested-by: Lee G Rosenbaum <lee.g.rosenbaum@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Cesar Eduardo Barros <cesarb@cesarb.net>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
In case of error, inet6_csk_update_pmtu() should consistently
return NULL.
Bug added in commit 35ad9b9cf7
(ipv6: Add helper inet6_csk_update_pmtu().)
Reported-by: Lluís Batlle i Rossell <viric@viric.name>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use &port->netdev->dev instead of NULL since dma_pool_create() doesn't
allow NULL dev.
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use &port->netdev->dev instead of NULL since dma_pool_create() doesn't
allow NULL dev.
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Without this udev doesn't have a way to key the ne device to the platform
device.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We mostly have pn533 fixes here, 2 memory leaks and an early unlocking fix.
Moreover, we also have an LLCP adapter linked list insertion fix.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.12 (GNU/Linux)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=w+Jg
-----END PGP SIGNATURE-----
Merge tag 'nfc-fixes-3.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/sameo/nfc-3.0
Samuel says:
"This is the first pull request for 3.7 NFC fixes.
We mostly have pn533 fixes here, 2 memory leaks and an early unlocking fix.
Moreover, we also have an LLCP adapter linked list insertion fix."
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The Intel 82855PM host bridge / Mobility FireGL 9000 RV250 combination
in an (outdated) ThinkPad T41 needs AGPMode 1 for suspend/resume (under
KMS, that is). So add a quirk for it.
(Change R250 to RV250 in comment for preceding quirk too.)
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
The save struct is not initialized previously so explicitly
mark the crtcs as not used when they are not in use.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
After the recent pile of disable-cloning patches, e.g.
commit e3b86d6941
Author: Egbert Eich <eich@suse.de>
Date: Sat Oct 13 14:30:15 2012 +0200
DRM/i915: Don't clone SDVO LVDS with analog
and a bug report from Chris Wilson indicating that cloning doesn't
even work for DVI-SDVO and native VGA, let's just disable cloning on
sdvo encoders completely.
v2: Update the comment in the code as discussed with Paulo Zanoni.
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=29259
Tested-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
After six and a half years of writing and maintaining KVM, it is time to
move to new things. Update my MAINTAINERS entry to reflect that.
Signed-off-by: Avi Kivity <avi@redhat.com>
Commit 8214513 ("ARM: EXYNOS: fix address for EXYNOS4 MDMA1")
changed EXYNOS specific setup of PL330 DMA engine to use 'non-secure'
mdma1 address instead of 'secure' one (from 0x12840000 to 0x12850000)
to fix issue with some Exynos4212 SOCs. Unfortunately it brakes
PL330 setup for revision 0 of Exynos4210 SOC (mdma1 device cannot
be found at 'non-secure' address):
[ 0.566245] dma-pl330 dma-pl330.2: PERIPH_ID 0x0, PCELL_ID 0x0 !
[ 0.566278] dma-pl330: probe of dma-pl330.2 failed with error -22
Fix it by using 'secure' mdma1 address on Exynos4210 revision 0 SOC.
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
blkdev_issue_discard currently assumes that the granularity
is a power of 2. So in raid5, round the chosen number up to
avoid embarrassment.
Cc: Shaohua Li <shli@kernel.org>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This also fixes a bug where the fence manager was left without irq
enabled when waiting for fences, causing various errors at module
load time
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Hiding SVGA seems to trigger a VGA screen clear, and with no
traces dirty it doesn't seem to repaint
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This is similar to other platforms that don't allow command submission
to buffers locked on the cpu.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Reservation locking currently always takes place under the LRU spinlock.
Hence, strictly there is no need for an atomic_cmpxchg call; we can use
atomic_read followed by atomic_write since nobody else will ever reserve
without the lru spinlock held.
At least on Intel this should remove a locked bus cycle on successful
reserve.
Note that thit commit may be obsoleted by the cross-device reservation work.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
The mostly used lookup+get put+potential_destroy path of TTM objects
is converted to use RCU locks. This will substantially decrease the amount
of locked bus cycles during normal operation.
Since we use kfree_rcu to free the objects, no rcu synchronization is needed
at module unload time.
v2: Don't touch include/linux/kref.h
v3: Adapt to kref_get_unless_zero return value change
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This function is intended to simplify locking around refcounting for
objects that can be looked up from a lookup structure, and which are
removed from that lookup structure in the object destructor.
Operations on such objects require at least a read lock around
lookup + kref_get, and a write lock around kref_put + remove from lookup
structure. Furthermore, RCU implementations become extremely tricky.
With a lookup followed by a kref_get_unless_zero *with return value check*
locking in the kref_put path can be deferred to the actual removal from
the lookup structure and RCU lookups become trivial.
v2: Formatting fixes.
v3: Invert the return value.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>