ALSA: sis7019 - give slow codecs more time to reset

commit fc084e0b930d546872ab23667052499f7daf0fed upstream.

There are some AC97 codec and board combinations that have been observed
to take a very long time to respond after the cold reset has completed.
In one case, more than 350 ms was required. To allow users to have sound
on those platforms, we'll wait up to 500ms for the codec to become
ready.

As a board may have multiple codecs, with some faster than others to
reset, we add a module parameter to inform the driver which codecs
should be present.

Reported-by: KotCzarny <tjosko@yahoo.com>
Signed-off-by: David Dillow <dave@thedillows.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
ALSA: hda/realtek - Fix Oops in alc_mux_select()

commit cce4aa378a049f4275416ee6302dd24f37b289df upstream.

When no imux is available (e.g. a single capture source),
alc_auto_init_input_src() may trigger an Oops due to the access to -1.
Add a proper zero-check to avoid it.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
ARM: davinci: da850 evm: change audio edma event queue to EVENTQ_0

commit f1b21c525693b0159aed83b5871f2d0f077f208e upstream.

On OMAP-L138 platform, EDMA event queue 0 should be used for audio
transfers so that they are not starved by video data moving on event queue 1.

Commit 48519f0ae03bc7e86b3dc93e56f1334d53803770 (ASoC: davinci: let platform
data define edma queue numbers) had a side-effect of changing this behavior
by making the driver actually honor the platform data passed.

Fix this now by passing event queue 0 as the queue to be used for audio
transfers.

Signed-off-by: Manjunathappa, Prakash <prakash.pm@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
arm: mx23: recognise stmp378x as mx23

commit 11357be9246c7d1acf9b37ad54a18b29bbb734be upstream.

Adding the machine_is_* line was forgotten when converting mach-stmp378x to
mach-mxs.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
ARM: at91: fix clock conid for atmel_tcb.1 on 9260/9g20

commit 1808958d27b1250295f01dff4997d8a8814adaab upstream.

The conid is supposed to be t0/t1/t2_clk.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
ARM: davinci: dm646x evm: wrong register used in setup_vpif_input_channel_mode

commit 83713fc9373be2e943f82e9d36213708c6b0050e upstream.

The function setup_vpif_input_channel_mode() used the VSCLKDIS register
instead of VIDCLKCTL. This meant that when in HD mode videoport channel 0
used a different clock from channel 1.

Clearly a copy-and-paste error.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Manjunath Hadli <manjunath.hadli@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
ASoC: Provide a more complete DMA driver stub

commit cefcc03ffc9527dde56807339edb1719c8dbae5f upstream.

Allow userspace applications to do more parameter setting by providing a
more complete stub DMA driver specifying a wildcard set of formats and
channels and essentially random values for the DMA parameters. This is
required for useful runtime operation of the dummy DMA driver until we
are able to figure out how to power up links and do hw_params() from DAPM.

Sending to stable as without this the dummy driver is not terribly
useful.

Reported-by: Kyung-Kwee Ryu <Kyung-Kwee.Ryu@wolfsonmicro.com>
Tested-by: Kyung-Kwee Ryu <Kyung-Kwee.Ryu@wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
fs/proc/meminfo.c: fix compilation error

commit b53fc7c2974a50913f49e1d800fe904a28c338e3 upstream.

Fix the error message "directives may not be used inside a macro argument"
which appears when the kernel is compiled for the cris architecture.

Signed-off-by: Claudio Scordino <claudio@evidence.eu.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
thp: add compound tail page _mapcount when mapped

commit b6999b19120931ede364fa3b685e698a61fed31d upstream.

With the 3.2-rc kernel, IOMMU 2M pages in KVM works.  But when I tried
to use IOMMU 1GB pages in KVM, I encountered an oops and the 1GB page
failed to be used.

The root cause is that 1GB page allocation calls gup_huge_pud() while 2M
page calls gup_huge_pmd.  If compound pages are used and the page is a
tail page, gup_huge_pmd() increases _mapcount to record tail page are
mapped while gup_huge_pud does not do that.

So when the mapped page is relesed, it will result in kernel oops
because the page is not marked mapped.

This patch add tail process for compound page in 1GB huge page which
keeps the same process as 2M page.

Reproduce like:
1. Add grub boot option: hugepagesz=1G hugepages=8
2. mount -t hugetlbfs -o pagesize=1G hugetlbfs /dev/hugepages
3. qemu-kvm -m 2048 -hda os-kvm.img -cpu kvm64 -smp 4 -mem-path /dev/hugepages
	-net none -device pci-assign,host=07:00.1

  kernel BUG at mm/swap.c:114!
  invalid opcode: 0000 [#1] SMP
  Call Trace:
    put_page+0x15/0x37
    kvm_release_pfn_clean+0x31/0x36
    kvm_iommu_put_pages+0x94/0xb1
    kvm_iommu_unmap_memslots+0x80/0xb6
    kvm_assign_device+0xba/0x117
    kvm_vm_ioctl_assigned_device+0x301/0xa47
    kvm_vm_ioctl+0x36c/0x3a2
    do_vfs_ioctl+0x49e/0x4e4
    sys_ioctl+0x5a/0x7c
    system_call_fastpath+0x16/0x1b
  RIP  put_compound_page+0xd4/0x168

Signed-off-by: Youquan Song <youquan.song@intel.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
thp: set compound tail page _count to zero

commit 58a84aa92723d1ac3e1cc4e3b0ff49291663f7e1 upstream.

Commit 70b50f94f1644 ("mm: thp: tail page refcounting fix") keeps all
page_tail->_count zero at all times.  But the current kernel does not
set page_tail->_count to zero if a 1GB page is utilized.  So when an
IOMMU 1GB page is used by KVM, it wil result in a kernel oops because a
tail page's _count does not equal zero.

  kernel BUG at include/linux/mm.h:386!
  invalid opcode: 0000 [#1] SMP
  Call Trace:
    gup_pud_range+0xb8/0x19d
    get_user_pages_fast+0xcb/0x192
    ? trace_hardirqs_off+0xd/0xf
    hva_to_pfn+0x119/0x2f2
    gfn_to_pfn_memslot+0x2c/0x2e
    kvm_iommu_map_pages+0xfd/0x1c1
    kvm_iommu_map_memslots+0x7c/0xbd
    kvm_iommu_map_guest+0xaa/0xbf
    kvm_vm_ioctl_assigned_device+0x2ef/0xa47
    kvm_vm_ioctl+0x36c/0x3a2
    do_vfs_ioctl+0x49e/0x4e4
    sys_ioctl+0x5a/0x7c
    system_call_fastpath+0x16/0x1b
  RIP  gup_huge_pud+0xf2/0x159

Signed-off-by: Youquan Song <youquan.song@intel.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
ptp: Fix clock_getres() implementation

commit d68fb11c3dae75c8331538dcf083a65e697cc034 upstream.

The clock_getres() function must return the resolution in the timespec
argument and return 0 for success.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <john.stultz@linaro.org>
Cc: Richard Cochran <richard.cochran@omicron.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
mm: vmalloc: check for page allocation failure before vmlist insertion

commit 1368edf0647ac112d8cfa6ce47257dc950c50f5c upstream.

Commit f5252e00 ("mm: avoid null pointer access in vm_struct via
/proc/vmallocinfo") adds newly allocated vm_structs to the vmlist after
it is fully initialised.  Unfortunately, it did not check that
__vmalloc_area_node() successfully populated the area.  In the event of
allocation failure, the vmalloc area is freed but the pointer to freed
memory is inserted into the vmlist leading to a a crash later in
get_vmalloc_info().

This patch adds a check for ____vmalloc_area_node() failure within
__vmalloc_node_range.  It does not use "goto fail" as in the previous
error path as a warning was already displayed by __vmalloc_area_node()
before it called vfree in its failure path.

Credit goes to Luciano Chavez for doing all the real work of identifying
exactly where the problem was.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reported-by: Luciano Chavez <lnx1138@linux.vnet.ibm.com>
Tested-by: Luciano Chavez <lnx1138@linux.vnet.ibm.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Conflicts:

	mm/vmalloc.c
fix apparmor dereferencing potentially freed dentry, sanitize __d_path() API

commit 02125a826459a6ad142f8d91c5b6357562f96615 upstream.

__d_path() API is asking for trouble and in case of apparmor d_namespace_path()
getting just that.  The root cause is that when __d_path() misses the root
it had been told to look for, it stores the location of the most remote ancestor
in *root.  Without grabbing references.  Sure, at the moment of call it had
been pinned down by what we have in *path.  And if we raced with umount -l, we
could have very well stopped at vfsmount/dentry that got freed as soon as
prepend_path() dropped vfsmount_lock.

It is safe to compare these pointers with pre-existing (and known to be still
alive) vfsmount and dentry, as long as all we are asking is "is it the same
address?".  Dereferencing is not safe and apparmor ended up stepping into
that.  d_namespace_path() really wants to examine the place where we stopped,
even if it's not connected to our namespace.  As the result, it looked
at ->d_sb->s_magic of a dentry that might've been already freed by that point.
All other callers had been careful enough to avoid that, but it's really
a bad interface - it invites that kind of trouble.

The fix is fairly straightforward, even though it's bigger than I'd like:
	* prepend_path() root argument becomes const.
	* __d_path() is never called with NULL/NULL root.  It was a kludge
to start with.  Instead, we have an explicit function - d_absolute_root().
Same as __d_path(), except that it doesn't get root passed and stops where
it stops.  apparmor and tomoyo are using it.
	* __d_path() returns NULL on path outside of root.  The main
caller is show_mountinfo() and that's precisely what we pass root for - to
skip those outside chroot jail.  Those who don't want that can (and do)
use d_path().
	* __d_path() root argument becomes const.  Everyone agrees, I hope.
	* apparmor does *NOT* try to use __d_path() or any of its variants
when it sees that path->mnt is an internal vfsmount.  In that case it's
definitely not mounted anywhere and dentry_path() is exactly what we want
there.  Handling of sysctl()-triggered weirdness is moved to that place.
	* if apparmor is asked to do pathname relative to chroot jail
and __d_path() tells it we it's not in that jail, the sucker just calls
d_absolute_path() instead.  That's the other remaining caller of __d_path(),
BTW.
        * seq_path_root() does _NOT_ return -ENAMETOOLONG (it's stupid anyway -
the normal seq_file logics will take care of growing the buffer and redoing
the call of ->show() just fine).  However, if it gets path not reachable
from root, it returns SEQ_SKIP.  The only caller adjusted (i.e. stopped
ignoring the return value as it used to do).

Reviewed-by: John Johansen <john.johansen@canonical.com>
ACKed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
target: Handle 0 correctly in transport_get_sectors_6()

commit 9b5cd7f37e1e018432111333e2a67f78ba41edfe upstream.

SBC-3 says:

    A TRANSFER LENGTH field set to zero specifies that 256 logical
    blocks shall be written.  Any other value specifies the number
    of logical blocks that shall be written.

The old code was always just returning the value in the TRANSFER LENGTH
byte.  Fix this to return 256 if the byte is 0.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
intel-iommu: fix return value of iommu_unmap() API

commit 292827cb164ad00cc7689a21283b1261c0b6daed upstream.

iommu_unmap() API expects IOMMU drivers to return the actual page order
of the address being unmapped.  Previous code was just returning page
order passed in from the caller.  This patch fixes this problem.

Signed-off-by: Allen Kay <allen.m.kay@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Youquan Song <youquan.song@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
intel-iommu: set iommu_superpage on VM domains to lowest common denominator

commit 8140a95d228efbcd64d84150e794761a32463947 upstream.

set dmar->iommu_superpage field to the smallest common denominator
of super page sizes supported by all active VT-d engines.  Initialize
this field in intel_iommu_domain_init() API so intel_iommu_map() API
will be able to use iommu_superpage field to determine the appropriate
super page size to use.

Signed-off-by: Allen Kay <allen.m.kay@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Youquan Song <youquan.song@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
intel-iommu: fix superpage support in pfn_to_dma_pte()

commit 4399c8bf2b9093696fa8160d79712e7346989c46 upstream.

If target_level == 0, current code breaks out of the while-loop if
SUPERPAGE bit is set. We should also break out if PTE is not present.
If we don't do this, KVM calls to iommu_iova_to_phys() will cause
pfn_to_dma_pte() to create mapping for 4KiB pages.

Signed-off-by: Allen Kay <allen.m.kay@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Youquan Song <youquan.song@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
iwlwifi: do not re-configure HT40 after associated

commit 34a5b4b6af104cf18eb50748509528b9bdbc4036 upstream.

The ht40 setting should not change after association unless channel switch

This fix a problem we are seeing which cause uCode assert because driver
sending invalid information and make uCode confuse

Here is the firmware assert message:
kernel: iwlagn 0000:03:00.0: Microcode SW error detected.  Restarting 0x82000000.
kernel: iwlagn 0000:03:00.0: Loaded firmware version: 17.168.5.3 build 42301
kernel: iwlagn 0000:03:00.0: Start IWL Error Log Dump:
kernel: iwlagn 0000:03:00.0: Status: 0x000512E4, count: 6
kernel: iwlagn 0000:03:00.0: 0x00002078 | ADVANCED_SYSASSERT
kernel: iwlagn 0000:03:00.0: 0x00009514 | uPc
kernel: iwlagn 0000:03:00.0: 0x00009496 | branchlink1
kernel: iwlagn 0000:03:00.0: 0x00009496 | branchlink2
kernel: iwlagn 0000:03:00.0: 0x0000D1F2 | interruptlink1
kernel: iwlagn 0000:03:00.0: 0x00000000 | interruptlink2
kernel: iwlagn 0000:03:00.0: 0x01008035 | data1
kernel: iwlagn 0000:03:00.0: 0x0000C90F | data2
kernel: iwlagn 0000:03:00.0: 0x000005A7 | line
kernel: iwlagn 0000:03:00.0: 0x5080B520 | beacon time
kernel: iwlagn 0000:03:00.0: 0xCC515AE0 | tsf low
kernel: iwlagn 0000:03:00.0: 0x00000003 | tsf hi
kernel: iwlagn 0000:03:00.0: 0x00000000 | time gp1
kernel: iwlagn 0000:03:00.0: 0x29703BF0 | time gp2
kernel: iwlagn 0000:03:00.0: 0x00000000 | time gp3
kernel: iwlagn 0000:03:00.0: 0x000111A8 | uCode version
kernel: iwlagn 0000:03:00.0: 0x000000B0 | hw version
kernel: iwlagn 0000:03:00.0: 0x00480303 | board version
kernel: iwlagn 0000:03:00.0: 0x09E8004E | hcmd
kernel: iwlagn 0000:03:00.0: CSR values:
kernel: iwlagn 0000:03:00.0: (2nd byte of CSR_INT_COALESCING is CSR_INT_PERIODIC_REG)
kernel: iwlagn 0000:03:00.0:        CSR_HW_IF_CONFIG_REG: 0X00480303
kernel: iwlagn 0000:03:00.0:          CSR_INT_COALESCING: 0X0000ff40
kernel: iwlagn 0000:03:00.0:                     CSR_INT: 0X00000000
kernel: iwlagn 0000:03:00.0:                CSR_INT_MASK: 0X00000000
kernel: iwlagn 0000:03:00.0:           CSR_FH_INT_STATUS: 0X00000000
kernel: iwlagn 0000:03:00.0:                 CSR_GPIO_IN: 0X00000030
kernel: iwlagn 0000:03:00.0:                   CSR_RESET: 0X00000000
kernel: iwlagn 0000:03:00.0:                CSR_GP_CNTRL: 0X080403c5
kernel: iwlagn 0000:03:00.0:                  CSR_HW_REV: 0X000000b0
kernel: iwlagn 0000:03:00.0:              CSR_EEPROM_REG: 0X07d60ffd
kernel: iwlagn 0000:03:00.0:               CSR_EEPROM_GP: 0X90000001
kernel: iwlagn 0000:03:00.0:              CSR_OTP_GP_REG: 0X00030001
kernel: iwlagn 0000:03:00.0:                 CSR_GIO_REG: 0X00080044
kernel: iwlagn 0000:03:00.0:            CSR_GP_UCODE_REG: 0X000093bb
kernel: iwlagn 0000:03:00.0:           CSR_GP_DRIVER_REG: 0X00000000
kernel: iwlagn 0000:03:00.0:           CSR_UCODE_DRV_GP1: 0X00000000
kernel: iwlagn 0000:03:00.0:           CSR_UCODE_DRV_GP2: 0X00000000
kernel: iwlagn 0000:03:00.0:                 CSR_LED_REG: 0X00000078
kernel: iwlagn 0000:03:00.0:        CSR_DRAM_INT_TBL_REG: 0X88214dd2
kernel: iwlagn 0000:03:00.0:        CSR_GIO_CHICKEN_BITS: 0X27800200
kernel: iwlagn 0000:03:00.0:             CSR_ANA_PLL_CFG: 0X00000000
kernel: iwlagn 0000:03:00.0:           CSR_HW_REV_WA_REG: 0X0001001a
kernel: iwlagn 0000:03:00.0:        CSR_DBG_HPET_MEM_REG: 0Xffff0010
kernel: iwlagn 0000:03:00.0: FH register values:
kernel: iwlagn 0000:03:00.0:         FH_RSCSR_CHNL0_STTS_WPTR_REG: 0X21316d00
kernel: iwlagn 0000:03:00.0:        FH_RSCSR_CHNL0_RBDCB_BASE_REG: 0X021479c0
kernel: iwlagn 0000:03:00.0:                  FH_RSCSR_CHNL0_WPTR: 0X00000060
kernel: iwlagn 0000:03:00.0:         FH_MEM_RCSR_CHNL0_CONFIG_REG: 0X80819104
kernel: iwlagn 0000:03:00.0:          FH_MEM_RSSR_SHARED_CTRL_REG: 0X000000fc
kernel: iwlagn 0000:03:00.0:            FH_MEM_RSSR_RX_STATUS_REG: 0X07030000
kernel: iwlagn 0000:03:00.0:    FH_MEM_RSSR_RX_ENABLE_ERR_IRQ2DRV: 0X00000000
kernel: iwlagn 0000:03:00.0:                FH_TSSR_TX_STATUS_REG: 0X07ff0001
kernel: iwlagn 0000:03:00.0:                 FH_TSSR_TX_ERROR_REG: 0X00000000
kernel: iwlagn 0000:03:00.0: Start IWL Event Log Dump: display last 20 entries
kernel: ------------[ cut here ]------------
WARNING: at net/mac80211/util.c:1208 ieee80211_reconfig+0x1f1/0x407()
kernel: Hardware name: 4290W4H
kernel: Pid: 1896, comm: kworker/0:0 Not tainted 3.1.0 #2
kernel: Call Trace:
kernel:  [<ffffffff81036558>] ? warn_slowpath_common+0x73/0x87
kernel:  [<ffffffff813b8966>] ? ieee80211_reconfig+0x1f1/0x407
kernel:  [<ffffffff8139e8dc>] ? ieee80211_recalc_smps_work+0x32/0x32
kernel:  [<ffffffff8139e95a>] ? ieee80211_restart_work+0x7e/0x87
kernel:  [<ffffffff810472fa>] ? process_one_work+0x1c8/0x2e3
kernel:  [<ffffffff810480c9>] ? worker_thread+0x17a/0x23a
kernel:  [<ffffffff81047f4f>] ? manage_workers.clone.18+0x15b/0x15b
kernel:  [<ffffffff81047f4f>] ? manage_workers.clone.18+0x15b/0x15b
kernel:  [<ffffffff8104ba97>] ? kthread+0x7a/0x82
kernel:  [<ffffffff813d21b4>] ? kernel_thread_helper+0x4/0x10
kernel:  [<ffffffff8104ba1d>] ? kthread_flush_work_fn+0x11/0x11
kernel:  [<ffffffff813d21b0>] ? gs_change+0xb/0xb

Reported-by: Udo Steinberg <udo@hypervisor.org>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
mac80211: fix race condition caused by late addBA response

Upstream commit d305a6557b2c4dca0110f05ffe745b1ef94adb80.

If addBA responses comes in just after addba_resp_timer has
expired mac80211 will still accept it and try to open the
aggregation session. This causes drivers to be confused and
in some cases even crash.

This patch fixes the race condition and makes sure that if
addba_resp_timer has expired addBA response is not longer
accepted and we do not try to open half-closed session.

Signed-off-by: Nikolay Martynov <mar.kolya@gmail.com>
[some adjustments]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
linux/log2.h: Fix rounddown_pow_of_two(1)

commit 13c07b0286d340275f2d97adf085cecda37ede37 upstream.

Exactly like roundup_pow_of_two(1), the rounddown version was buggy for
the case of a compile-time constant '1' argument.  Probably because it
originated from the same code, sharing history with the roundup version
from before the bugfix (for that one, see commit 1a06a52ee1b0: "Fix
roundup_pow_of_two(1)").

However, unlike the roundup version, the fix for rounddown is to just
remove the broken special case entirely.  It's simply not needed - the
generic code

    1UL << ilog2(n)

does the right thing for the constant '1' argment too.  The only reason
roundup needed that special case was because rounding up does so by
subtracting one from the argument (and then adding one to the result)
causing the obvious problems with "ilog2(0)".

But rounddown doesn't do any of that, since ilog2() naturally truncates
(ie "rounds down") to the right rounded down value.  And without the
ilog2(0) case, there's no reason for the special case that had the wrong
value.

tl;dr: rounddown_pow_of_two(1) should be 1, not 0.

Acked-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>