If the device isn't reset, the XHCI HCD sends
SET ADDRESS to address 0 while the device is
already in Addressed state, and the request is
dropped on the floor as it is addressed to the
default address. This sequence of events, which this
patch fixes looks like this:
usb_reset_and_verify_device()
hub_port_init()
hub_set_address()
SET_ADDRESS to 0 with 1
usb_get_device_descriptor(udev, 8)
usb_get_device_descriptor(udev, 18)
descriptors_changed() --> goto re_enumerate:
hub_port_logical_disconnect()
kick_khubd()
And then:
hub_events()
hub_port_connect_change()
usb_disconnect()
usb_disable_device()
new device struct
sets device state to Powered
choose_address()
hub_port_init() <-- no reset, but SET ADDRESS to 0 with 1, timeout!
The solution is to always reset the device in
hub_port_init() to put it in a known state.
Note from Sarah Sharp:
This patch should be queued for stable trees all the way back to 2.6.34,
since that was the first kernel that supported configured device reset.
The code this patch touches has been there since 2.6.32, but the bug
would never be hit before 2.6.34 because the xHCI driver would
completely reject an attempt to reset a configured device under xHCI.
Signed-off-by: Luben Tuikov <ltuikov@yahoo.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@kernel.org
The expression
while (running_total < sg_dma_len(sg))
does not take into account that the remaining data length can be less
than sg_dma_len(sg). In that case, running_total can end up being
greater than the total data length, so an extra TRB is counted.
Changing the expression to
while (running_total < sg_dma_len(sg) && running_total < temp)
fixes that.
This patch should be queued for stable kernels back to 2.6.31.
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@kernel.org
Calculations like
running_total = TRB_MAX_BUFF_SIZE -
(sg_dma_address(sg) & (TRB_MAX_BUFF_SIZE - 1));
if (running_total != 0)
num_trbs++;
are incorrect, because running_total can never be zero, so the if()
expression will never be true. I think the intention was that
running_total be in the range of 0 to TRB_MAX_BUFF_SIZE-1, not 1
to TRB_MAX_BUFF_SIZE. So adding a
running_total &= TRB_MAX_BUFF_SIZE - 1;
fixes the problem.
This patch should be queued for stable kernels back to 2.6.31.
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@kernel.org
This makes it easier to spot some problems, which will be fixed by the
next patch in the series. Also change dev_dbg to dev_err in
check_trb_math(), so any math errors will be visible even when running
with debug disabled.
Note: This patch changes the expressions containing
"((1 << TRB_MAX_BUFF_SHIFT) - 1)" to use the equivalent
"(TRB_MAX_BUFF_SIZE - 1)". No change in behavior is intended for
those expressions.
This patch should be queued for stable kernels back to 2.6.31.
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@kernel.org
Change the BUGs in xhci_find_new_dequeue_state() to WARN_ONs, to avoid
bringing down the box if one of them is hit
This patch should be queued for stable kernels back to 2.6.31.
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@kernel.org
Allow drivers to enable Zoomed Video support. Currently, this is only
used by out-of-tree drivers (L64020 DVB driver in particular).
CC: <stable@kernel.org> [for 2.6.37]
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Commit 2c442719e9 added some checks for proper
heartbeat mode when the o2cb stack is running. Unfortunately, it didn't
take into account that a userpsace stack could be running. Fix this by only
doing the check if o2cb is in use. This patch allows userspace stacks to
mount the fs again.
Cc: stable@kernel.org
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Joel Becker <jlbec@evilplan.org>
Current refcounttree codes actually didn't writeback the new pages out in
write-back mode, due to a bug of always passing a ZERO number of clusters
to 'ocfs2_cow_sync_writeback', the patch tries to pass a proper one in.
Signed-off-by: Tristan Ye <tristan.ye@oracle.com>
Cc: stable@kernel.org
Signed-off-by: Joel Becker <jlbec@evilplan.org>
In the rare case that INLINE_DATA, INDEX_DIR, QUOTA, XATTR features are
disabled and both the allocation of the directory inode and the allocation
of the first directory block need to relink allocation group, there need
not be enough credits reserved in a transaction. Fix the estimate.
CC: Mark Fasheh <mfasheh@suse.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Joel Becker <jlbec@evilplan.org>
When creating a new dentry we now hold a reference to the parent
inode in the ceph_dentry. This is required due to the new RCU
changes from 949854d0, which set dentry->d_parent to NULL in d_kill before
calling the ->release() callback. If/when that behavior is changed, we can
revert this hack.
Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
commit 5fa782c2f5 re-worked the
handling of unknown parameters. sctp_init_cause_fixed() can now
return -ENOSPC if there is not enough tailroom in the error
chunk skb. When this happens, the error header is not appended to
the error chunk. In that case, the payload of the unknown parameter
should not be appended either.
Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Acked-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The dcb_app protocol field is a __u32 however the 802.1Qaz
specification defines it as a 16 bit field. This patch brings
the structure inline with the spec making it a __u16.
CC: Shmulik Ravid <shmulikr@broadcom.com>
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric W. Biederman reported a lockdep splat in inet_twsk_deschedule()
This is caused by inet_twsk_purge(), run from process context,
and commit 575f4cd5a5 (net: Use rcu lookups in inet_twsk_purge.)
removed the BH disabling that was necessary.
Add the BH disabling but fine grained, right before calling
inet_twsk_deschedule(), instead of whole function.
With help from Linus Torvalds and Eric W. Biederman
Reported-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Daniel Lezcano <daniel.lezcano@free.fr>
CC: Pavel Emelyanov <xemul@openvz.org>
CC: Arnaldo Carvalho de Melo <acme@redhat.com>
CC: stable <stable@kernel.org> (# 2.6.33+)
Signed-off-by: David S. Miller <davem@davemloft.net>
Without this patch, one line-out and one speaker and
Conexant's auto parser would announce (non-working) surround
capabilities.
BugLink: http://bugs.launchpad.net/bugs/721126
Cc: stable@kernel.org
Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Conexant 20641 has several inputs to its ADC node, with one selector
and individual amps for all inputs. This patch adds support in the
Conexant auto parser to handle that case.
It also means that the pin node's volume is being renamed to "Boost"
to avoid name clash with the new volume controls on the ADC node.
BugLink: http://bugs.launchpad.net/bugs/719524
Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
If ID_MMFR0[3:0] >= 3, the architecture version is ARMv7. The code was
currently only testing for ID_MMFR0[3:0] == 3.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
On versions of the Cortex-A9 prior to r3p0, an interrupted ICIALLUIS
operation may prevent the completion of a following broadcasted
operation if the second operation is received by a CPU before the
ICIALLUIS has completed, potentially leading to corrupted entries in
the cache or TLB.
This workaround sets a bit in the diagnostic register of the Cortex-A9,
causing CP15 maintenance operations to be uninterruptible.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Now that we can execute a CONFIG_SMP kernel on a uniprocessor system,
extra care has to be taken in the PMU IRQ affinity setting code to
ensure that we don't always fail to initialise.
This patch changes the CPU PMU initialisation code so that when we
only have a single IRQ, whose affinity can not be changed at the
controller, we report success (0) rather than -EINVAL.
Reported-by: Avik Sil <avik.sil@linaro.org>
Acked-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The effect of cache sync operation is to drain the store buffer and
wait for all internal buffers to be empty. In normal conditions, store
buffer is able to merge the normal memory writes within its 32-byte
data buffers. Due to this erratum present in r3p0, the effect of cache
sync operation on the store buffer still remains when the operation
completes. This means that the store buffer is always asked to drain
and this prevents it from merging any further writes.
This can severely affect performance on the write traffic esp. on
Normal memory NC one.
The proposed workaround is to replace the normal offset of cache sync
operation(0x730) by another offset targeting an unmapped PL310
register 0x740.
Signed-off-by: srinidhi kasagar <srinidhi.kasagar@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
After 2.6.34 changes, __pxa2xx_drv_pcmcia_probe() was replaced by
sa1111_pcmcia_add(). That unfortunately means that configure_sockets()
is not called, leading to MECR not being set properly, leading to
strange crashes.
Tested on pxa255+sa1111, I do not have lubbock board nearby. Perhaps
cleaner solution exists?
Signed-off-by: Pavel Machek <pma@sysgo.com>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Request_region should be used with release_region, not release_resource.
This patch contains a number of changes, related to calls to request_region,
request_mem_region, and the associated error handling code.
1. For the call to request_region, the variable io_resource storing the
result is dropped. The call to release_resource at the end of the function
is changed to a call to release_region with the first two arguments of
request_region as its arguments. The same call to release_region is also
added to release_ipwireless.
2. The first call to request_mem_region is now tested and ret is set to
-EBUSY if the the call has failed. This call was associated with the
initialization of ipw->attr_memory. But the error handling code was
testing ipw->common_memory. The definition of release_ipwireless also
suggests that this call should be associated with ipw->common_memory, not
ipw->attr_memory.
3. The second call to request_mem_region is now tested and ret is
set to -EBUSY if the the call has failed.
4. The various gotos to the error handling code is adjusted so that there
is no need for ifs.
5. Return the value stored in the ret variable rather than -1.
The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
expression x,E;
@@
(
*x = request_region(...)
|
*x = request_mem_region(...)
)
... when != release_region(x)
when != x = E
* release_resource(x);
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
With CONFIG_SHIRQ_DEBUG=y we call a newly installed interrupt handler
in request_threaded_irq().
The original implementation (commit a304e1b8) called the handler
_BEFORE_ it was installed, but that caused problems with handlers
calling disable_irq_nosync(). See commit 377bf1e4.
It's braindead in the first place to call disable_irq_nosync in shared
handlers, but ....
Moving this call after we installed the handler looks innocent, but it
is very subtle broken on SMP.
Interrupt handlers rely on the fact, that the irq core prevents
reentrancy.
Now this debug call violates that promise because we run the handler
w/o the IRQ_INPROGRESS protection - which we cannot apply here because
that would result in a possibly forever masked interrupt line.
A concurrent real hardware interrupt on a different CPU results in
handler reentrancy and can lead to complete wreckage, which was
unfortunately observed in reality and took a fricking long time to
debug.
Leave the code here for now. We want this debug feature, but that's
not easy to fix. We really should get rid of those
disable_irq_nosync() abusers and remove that function completely.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Anton Vorontsov <avorontsov@ru.mvista.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: stable@kernel.org # .28 -> .37
Lars-Peter Clausen pointed out:
I stumbled upon this while looking through the existing archs using
SPARSE_IRQ. Even with SPARSE_IRQ the NR_IRQS is still the upper
limit for the number of IRQs.
Both PXA and MMP set NR_IRQS to IRQ_BOARD_START, with
IRQ_BOARD_START being the number of IRQs used by the core.
In various machine files the nr_irqs field of the ARM machine
defintion struct is then set to "IRQ_BOARD_START + NR_BOARD_IRQS".
As a result "nr_irqs" will greater then NR_IRQS which then again
causes the "allocated_irqs" bitmap in the core irq code to be
accessed beyond its size overwriting unrelated data.
The core code really misses a sanity check there.
This went unnoticed so far as by chance the compiler/linker places
data behind that bitmap which gets initialized later on those affected
platforms.
So the obvious fix would be to add a sanity check in early_irq_init()
and break all affected platforms. Though that check wants to be
backported to stable as well, which will require to fix all known
problematic platforms and probably some more yet not known ones as
well. Lots of churn.
A way simpler solution is to allocate a slightly larger bitmap and
avoid the whole churn w/o breaking anything. Add a few warnings when
an arch returns utter crap.
Reported-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org # .37
Cc: Haojian Zhuang <haojian.zhuang@marvell.com>
Cc: Eric Miao <eric.y.miao@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Change my email address to my main account.
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The interface is identical EMC6D102, so all that needs to be added are
some definitions and their uses.
Registers apparently missing in EMC6D103S/EMC6D103:A2 compared to EMC6D103:A0,
EMC6D103:A1, and EMC6D102 (according to the data sheets), but used
unconditionally in the driver: 62[5:7], 6D[0:7], and 6E[0:7]. For that
reason, EMC6D103S chips don't get enabled for the time being.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
(Guenter Roeck: Replaced EMC6D103_A2 with EMC6D103S per EMC6D103S datasheet)
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Cc: stable@kernel.org
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (37 commits)
net: deinit automatic LIST_HEAD
net: dont leave active on stack LIST_HEAD
net: provide default_advmss() methods to blackhole dst_ops
tg3: Restrict phy ioctl access
drivers/net: Call netif_carrier_off at the end of the probe
ixgbe: work around for DDP last buffer size
ixgbe: fix panic due to uninitialised pointer
e1000e: flush all writebacks before unload
e1000e: check down flag in tasks
isdn: hisax: Use l2headersize() instead of dup (and buggy) func.
arp_notify: unconditionally send gratuitous ARP for NETDEV_NOTIFY_PEERS.
cxgb4vf: Use defined Mailbox Timeout
cxgb4vf: Quiesce Virtual Interfaces on shutdown ...
cxgb4vf: Behave properly when CONFIG_DEBUG_FS isn't defined ...
cxgb4vf: Check driver parameters in the right place ...
pch_gbe: Fix the MAC Address load issue.
iwlwifi: Delete iwl3945_good_plcp_health.
net/can/softing: make CAN_SOFTING_CS depend on CAN_SOFTING
netfilter: nf_iterate: fix incorrect RCU usage
pch_gbe: Fix the issue that the receiving data is not normal.
...
Correct channel setting function must be used for AR2317.
When I tested ahb patch on bullet2 all seemed to work fine,
but it couldn't connect another host (using ibss for example).
During an analysis I observed that it's transmitting on another
channel. I looked into madwifi code and understood that
the problem is in channel setting function. So atheros RF2317 not
fully handled in the current ath5k version and must be patched.
Signed-off-by: Nikolay Ledovskikh <nledovskikh@gmail.com>
Acked-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
taken two RT35XX EDIMAX from DPO_RT3562_3592_3062_LinuxSTA_V2.4.1.1_20101217
Signed-off-by: Xose Vazquez Perez <xose.vazquez@gmail.com>
Acked-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
* 'fixes-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: make sure MAYDAY_INITIAL_TIMEOUT is at least 2 jiffies long
workqueue, freezer: unify spelling of 'freeze' + 'able' to 'freezable'
workqueue: wake up a worker when a rescuer is leaving a gcwq
commit 9b5e383c11 (net: Introduce
unregister_netdevice_many()) left an active LIST_HEAD() in
rollback_registered(), with possible memory corruption.
Even if device is freed without touching its unreg_list (and therefore
touching the previous memory location holding LISTE_HEAD(single), better
close the bug for good, since its really subtle.
(Same fix for default_device_exit_batch() for completeness)
Reported-by: Michal Hocko <mhocko@suse.cz>
Tested-by: Michal Hocko <mhocko@suse.cz>
Reported-by: Eric W. Biderman <ebiderman@xmission.com>
Tested-by: Eric W. Biderman <ebiderman@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Ingo Molnar <mingo@elte.hu>
CC: Octavian Purdila <opurdila@ixiacom.com>
CC: stable <stable@kernel.org> [.33+]
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric W. Biderman and Michal Hocko reported various memory corruptions
that we suspected to be related to a LIST head located on stack, that
was manipulated after thread left function frame (and eventually exited,
so its stack was freed and reused).
Eric Dumazet suggested the problem was probably coming from commit
443457242b (net: factorize
sync-rcu call in unregister_netdevice_many)
This patch fixes __dev_close() and dev_close() to properly deinit their
respective LIST_HEAD(single) before exiting.
References: https://lkml.org/lkml/2011/2/16/304
References: https://lkml.org/lkml/2011/2/14/223
Reported-by: Michal Hocko <mhocko@suse.cz>
Tested-by: Michal Hocko <mhocko@suse.cz>
Reported-by: Eric W. Biderman <ebiderman@xmission.com>
Tested-by: Eric W. Biderman <ebiderman@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Ingo Molnar <mingo@elte.hu>
CC: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 0dbaee3b37 (net: Abstract default ADVMSS behind an
accessor.) introduced a possible crash in tcp_connect_init(), when
dst->default_advmss() is called from dst_metric_advmss()
Reported-by: George Spelvin <linux@horizon.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When list debugging is enabled, we aim to readably show list corruption
errors, and the basic list_add/list_del operations end up having extra
debugging code in them to do some basic validation of the list entries.
However, "list_del_init()" and "list_move[_tail]()" ended up avoiding
the debug code due to how they were written. This fixes that.
So the _next_ time we have list_move() problems with stale list entries,
we'll hopefully have an easier time finding them..
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add Fn keymap support to allow for internal processing of Fn keys.
Signed-off-by: Rakesh Iyer <riyer@nvidia.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
ftp://pub.kernel.org/pub/linux/kernel/people/groeck/linux-staging/
is not kept up to date, so remove reference to it.
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Add the PCI ID to support the internal temperature sensor of the
AMD "Llano" and "Brazos" processor families.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Cc: stable@kernel.org # ca86828: x86, AMD, PCI: Add AMD northbridge PCI device
Cc: stable@kernel.org
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Since commit 1130e5b3ff regulators are exported to debugfs. The names
of the regulators that contains slash ('/') causes an ops during kernel
boot. This patch fixes this issue.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Max8998 PMIC driver's platform data has been changed once again in
commit 735a3d9efd. This patch fixes build break caused by that commit.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
s3c24xx_ts_set_platdata is annotated __init and not used by any module,
thus don't export it.
This patch fixes below warning:
WARNING: arch/arm/plat-samsung/built-in.o(__ksymtab+0x90): Section mismatch
in reference from the variable __ksymtab_s3c24xx_ts_set_platdata to the
function .init.text:s3c24xx_ts_set_platdata()
The symbol s3c24xx_ts_set_platdata is exported and annotated __init
Fix this by removing the __init annotation of s3c24xx_ts_set_platdata
or drop the export.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
This reverts commit 21edad3220 and commit
93c3fe40c2, which fixed a regression by
the former.
Al Viro pointed out bypassed dcache lookups in
ecryptfs_new_lower_dentry(), misuse of vfs_path_lookup() in
ecryptfs_lookup_one_lower() and a dislike of passing nameidata to the
lower filesystem.
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
* 'drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6:
drm/radeon/kms: add missing frac fb div flag for dce4+
drm/radeon/kms: do not reject X16 and Y16X16 floating-point formats on r300
drm/nouveau: fix suspend/resume on GPUs that don't have PM support
drm/nouveau: flips/flipd need to always set 'evict' for move_accel_cleanup()
drm/nv40: fix tiling-related setup for a number of chipsets
drm/nouveau: fix non-EDIDful native mode selection
drm/nouveau: Fix detection of DDC-based LVDS on DCB15 boards.
drm/nv04-nv40: Fix NULL dereference when we fail to find an LVDS native mode.
drm/nv10: Fix crash when allocating a BO larger than half the available VRAM.