* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: Clear TS in irq_ts_save() when in an atomic section
x86: Detect use of extended APIC ID for AMD CPUs
x86: memtest: remove 64-bit division
x86, UV: Fix macros for multiple coherency domains
x86: Fix non-lazy GS handling in sys_vm86()
x86: Add quirk for reboot stalls on a Dell Optiplex 360
x86: Fix UV BAU activation descriptor init
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (22 commits)
x86: fix system without memory on node0
x86, mm: Fix node_possible_map logic
mm, x86: remove MEMORY_HOTPLUG_RESERVE related code
x86: make sparse mem work in non-NUMA mode
x86: process.c, remove useless headers
x86: merge process.c a bit
x86: use sparse_memory_present_with_active_regions() on UMA
x86: unify 64-bit UMA and NUMA paging_init()
x86: Allow 1MB of slack between the e820 map and SRAT, not 4GB
x86: Sanity check the e820 against the SRAT table using e820 map only
x86: clean up and and print out initial max_pfn_mapped
x86/pci: remove rounding quirk from e820_setup_gap()
x86, e820, pci: reserve extra free space near end of RAM
x86: fix typo in address space documentation
x86: 46 bit physical address support on 64 bits
x86, mm: fault.c, use printk_once() in is_errata93()
x86: move per-cpu mmu_gathers to mm/init.c
x86: move max_pfn_mapped and max_low_pfn_mapped to setup.c
x86: unify noexec handling
x86: remove (null) in /sys kernel_page_tables
...
* 'x86-microcode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, microcode: Simplify vfree() use
x86: microcode: use smp_call_function_single instead of set_cpus_allowed, cleanup of synchronization logic
* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: cpu_debug: Remove model information to reduce encoding-decoding
x86: fixup numa_node information for AMD CPU northbridge functions
x86: k8 convert node_to_k8_nb_misc() from a macro to an inline function
x86: cacheinfo: complete L2/L3 Cache and TLB associativity field definitions
x86/docs: add description for cache_disable sysfs interface
x86: cacheinfo: disable L3 ECC scrubbing when L3 cache index is disabled
x86: cacheinfo: replace sysfs interface for cache_disable feature
x86: cacheinfo: use cached K8 NB_MISC devices instead of scanning for it
x86: cacheinfo: correct return value when cache_disable feature is not active
x86: cacheinfo: use L3 cache index disable feature only for CPUs that support it
* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, nmi: Use predefined numbers instead of hardcoded one
x86: asm/processor.h: remove double declaration
x86, mtrr: replace MTRRdefType_MSR with msr-index's MSR_MTRRdefType
x86, mtrr: replace MTRRfix4K_C0000_MSR with msr-index's MSR_MTRRfix4K_C0000
x86, mtrr: remove mtrr MSRs double declaration
x86, mtrr: replace MTRRfix16K_80000_MSR with msr-index's MSR_MTRRfix16K_80000
x86, mtrr: replace MTRRfix64K_00000_MSR with msr-index's MSR_MTRRfix64K_00000
x86, mtrr: replace MTRRcap_MSR with msr-index's MSR_MTRRcap
x86: mce: remove duplicated #include
x86: msr-index.h remove duplicate MSR C001_0015 declaration
x86: clean up arch/x86/kernel/tsc_sync.c a bit
x86: use symbolic name for VM86_SIGNAL when used as vm86 default return
x86: added 'ifndef _ASM_X86_IOMAP_H' to iomap.h
x86: avoid multiple declaration of kstack_depth_to_print
x86: vdso/vma.c declare vdso_enabled and arch_setup_additional_pages before they get used
x86: clean up declarations and variables
x86: apic/x2apic_cluster.c x86_cpu_to_logical_apicid should be static
x86 early quirks: eliminate unused function
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, 64-bit: ifdef out struct thread_struct::ip
x86, 32-bit: ifdef out struct thread_struct::fs
x86: clean up alternative.h
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: fix typo in sched-rt-group.txt file
ftrace: fix typo about map of kernel priority in ftrace.txt file.
sched: properly define the sched_group::cpumask and sched_domain::span fields
sched, timers: cleanup avenrun users
sched, timers: move calc_load() to scheduler
sched: Don't export sched_mc_power_savings on multi-socket single core system
sched: emit thread info flags with stack trace
sched: rt: document the risk of small values in the bandwidth settings
sched: Replace first_cpu() with cpumask_first() in ILB nomination code
sched: remove extra call overhead for schedule()
sched: use group_first_cpu() instead of cpumask_first(sched_group_cpus())
wait: don't use __wake_up_common()
sched: Nominate a power-efficient ilb in select_nohz_balancer()
sched: Nominate idle load balancer from a semi-idle package.
sched: remove redundant hierarchy walk in check_preempt_wakeup
* 'x86-kbuild-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (46 commits)
x86, boot: add new generated files to the appropriate .gitignore files
x86, boot: correct the calculation of ZO_INIT_SIZE
x86-64: align __PHYSICAL_START, remove __KERNEL_ALIGN
x86, boot: correct sanity checks in boot/compressed/misc.c
x86: add extension fields for bootloader type and version
x86, defconfig: update kernel position parameters
x86, defconfig: update to current, no material changes
x86: make CONFIG_RELOCATABLE the default
x86: default CONFIG_PHYSICAL_START and CONFIG_PHYSICAL_ALIGN to 16 MB
x86: document new bzImage fields
x86, boot: make kernel_alignment adjustable; new bzImage fields
x86, boot: remove dead code from boot/compressed/head_*.S
x86, boot: use LOAD_PHYSICAL_ADDR on 64 bits
x86, boot: make symbols from the main vmlinux available
x86, boot: determine compressed code offset at compile time
x86, boot: use appropriate rep string for move and clear
x86, boot: zero EFLAGS on 32 bits
x86, boot: set up the decompression stack as early as possible
x86, boot: straighten out ranges to copy/zero in compressed/head*.S
x86, boot: stylistic cleanups for boot/compressed/head_64.S
...
Fixed trivial conflict in arch/x86/configs/x86_64_defconfig manually
* 'irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (76 commits)
x86, apic: Fix dummy apic read operation together with broken MP handling
x86, apic: Restore irqs on fail paths
x86: Print real IOAPIC version for x86-64
x86: enable_update_mptable should be a macro
sparseirq: Allow early irq_desc allocation
x86, io-apic: Don't mark pin_programmed early
x86, irq: don't call mp_config_acpi_gsi() if update_mptable is not enabled
x86, irq: update_mptable needs pci_routeirq
x86: don't call read_apic_id if !cpu_has_apic
x86, apic: introduce io_apic_irq_attr
x86/pci: add 4 more return parameters to IO_APIC_get_PCI_irq_vector(), fix
x86: read apic ID in the !acpi_lapic case
x86: apic: Fixmap apic address even if apic disabled
x86: display extended apic registers with print_local_APIC and cpu_debug code
x86: read apic ID in the !acpi_lapic case
x86: clean up and fix setup_clear/force_cpu_cap handling
x86: apic: Check rev 3 fadt correctly for physical_apic bit
x86/pci: update pirq_enable_irq() to setup io apic routing
x86/acpi: move setup io apic routing out of CONFIG_ACPI scope
x86/pci: add 4 more return parameters to IO_APIC_get_PCI_irq_vector()
...
The e_powersaver driver for VIA's C7 CPU's needs to be marked as
DANGEROUS as it configures the CPU to power states that are out
of specification.
According to Centaur, all systems with C7 and Nano CPU's support
the ACPI p-state method. Thus, the acpi-cpufreq driver should
be used instead.
Signed-off-by: Harald Welte <HaraldWelte@viatech.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The VIA/Centaur C7, C7-M and Nano CPU's all support ACPI based cpu p-states
using a MSR interface. The Linux driver just never made use of it, since in
addition to the check for the EST flag it also checked if the vendor is Intel.
Signed-off-by: Harald Welte <HaraldWelte@viatech.com>
[ Removed the vendor checks entirely - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This helps with bad latencies for large reads from /dev/zero, but might
conceivably break some application that "knows" that a read of /dev/zero
cannot return early. So do this early in the merge window to give us
maximal test coverage, even if the patch is totally trivial.
Obviously, no well-behaved application should ever depend on the read
being uninterruptible, but hey, bugs happen.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There's a bug in the mxser kernel module that still appears in the
2.6.29.4 kernel.
mxser_get_ISA_conf takes a ioaddress as its first argument, by passing the
not of the ioaddr, you're effectively passing 0 which means it won't be
able to talk to an ISA card. I have tested this, and removing the !
fixes the problem.
Cc: "Peter Botha" <peterb@goldcircle.co.za>
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In commit code, we scan buffers attached to a transaction. During this
scan, we sometimes have to drop j_list_lock and then we recheck whether
the journal buffer head didn't get freed by journal_try_to_free_buffers().
But checking for buffer_jbd(bh) isn't enough because a new journal head
could get attached to our buffer head. So add a check whether the journal
head remained the same and whether it's still at the same transaction and
list.
This is a nasty bug and can cause problems like memory corruption (use after
free) or trigger various assertions in JBD code (observed).
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: <stable@kernel.org>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The recent ->lookup() deadlock correction required the directory inode
mutex to be dropped while waiting for expire completion. We were
concerned about side effects from this change and one has been identified.
I saw several error messages.
They cause autofs to become quite confused and don't really point to the
actual problem.
Things like:
handle_packet_missing_direct:1376: can't find map entry for (43,1827932)
which is usually totally fatal (although in this case it wouldn't be
except that I treat is as such because it normally is).
do_mount_direct: direct trigger not valid or already mounted
/test/nested/g3c/s1/ss1
which is recoverable, however if this problem is at play it can cause
autofs to become quite confused as to the dependencies in the mount tree
because mount triggers end up mounted multiple times. It's hard to
accurately check for this over mounting case and automount shouldn't need
to if the kernel module is doing its job.
There was one other message, similar in consequence of this last one but I
can't locate a log example just now.
When checking if a mount has already completed prior to adding a new mount
request to the wait queue we check if the dentry is hashed and, if so, if
it is a mount point. But, if a mount successfully completed while we
slept on the wait queue mutex the dentry must exist for the mount to have
completed so the test is not really needed.
Mounts can also be done on top of a global root dentry, so for the above
case, where a mount request completes and the wait queue entry has already
been removed, the hashed test returning false can cause an incorrect
callback to the daemon. Also, d_mountpoint() is not sufficient to check
if a mount has completed for the multi-mount case when we don't have a
real mount at the base of the tree.
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The massive nommu update (8feae131) resulted in these warnings:
ipc/shm.c: In function `sys_shmdt':
ipc/shm.c:974: warning: unused variable `size'
ipc/shm.c:972: warning: unused variable `next'
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
cls_cgroup: Fix oops when user send improperly 'tc filter add' request
r8169: fix crash when large packets are received
* 'for-linus' of git://neil.brown.name/md:
md/raid5: fix bug in reshape code when chunk_size decreases.
md/raid5 - avoid deadlocks in get_active_stripe during reshape
md/raid5: use conf->raid_disks in preference to mddev->raid_disk
Booting a 32-bit kernel on Magny-Cours results in the following panic:
...
Using APIC driver default
...
Overriding APIC driver with bigsmp
...
Getting VERSION: 80050010
Getting VERSION: 80050010
Getting ID: 10000000
Getting ID: ef000000
Getting LVT0: 700
Getting LVT1: 10000
Kernel panic - not syncing: Boot APIC ID in local APIC unexpected (16 vs 0)
Pid: 1, comm: swapper Not tainted 2.6.30-rcX #2
Call Trace:
[<c05194da>] ? panic+0x38/0xd3
[<c0743102>] ? native_smp_prepare_cpus+0x259/0x31f
[<c073b19d>] ? kernel_init+0x3e/0x141
[<c073b15f>] ? kernel_init+0x0/0x141
[<c020325f>] ? kernel_thread_helper+0x7/0x10
The reason is that default_get_apic_id handled extension of local APIC
ID field just in case of XAPIC.
Thus for this AMD CPU, default_get_apic_id() returns 0 and
bigsmp_get_apic_id() returns 16 which leads to the respective kernel
panic.
This patch introduces a Linux specific feature flag to indicate
support for extended APIC id (8 bits instead of 4 bits width) and sets
the flag on AMD CPUs if applicable.
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: <stable@kernel.org>
LKML-Reference: <20090608135509.GA12431@alberich.amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Due to commit 1cd96c242a ("block: WARN
in __blk_put_request() for potential bio leak"), BSG SMP requests get
the false warnings:
WARNING: at block/blk-core.c:1068 __blk_put_request+0x52/0xc0()
This sets rq->bio to NULL to avoid that false warnings.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
These are defined as static cpumask_var_t so if MAXSMP is not used,
they are cleared already. Avoid surprises when MAXSMP is enabled.
Signed-off-by: Yinghai Lu <yinghai.lu@kernel.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
I found a bug in cls_cgroup_change() in cls_cgroup.c.
cls_cgroup_change() expected tca[TCA_OPTIONS] was set from user space properly,
but tc in iproute2-2.6.29-1 (which I used) didn't set it.
In the current source code of tc in git, it set tca[TCA_OPTIONS].
git://git.kernel.org/pub/scm/linux/kernel/git/shemminger/iproute2.git
If we always use a newest iproute2 in git when we use cls_cgroup,
we don't face this oops probably.
But I think, kernel shouldn't panic regardless of use program's behaviour.
Signed-off-by: Minoru Usui <usui@mxm.nes.nec.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
Michael Tokarev reported receiving a large packet could crash
a machine with RTL8169 NIC.
( original thread at http://lkml.org/lkml/2009/6/8/192 )
Problem is this driver tells that NIC frames up to 16383 bytes
can be received but provides skb to rx ring allocated with
smaller sizes (1536 bytes in case standard 1500 bytes MTU is used)
When a frame larger than what was allocated by driver is received,
dma transfert can occurs past the end of buffer and corrupt
kernel memory.
Fix is to tell to NIC what is the maximum size a frame can be.
This bug is very old, (before git introduction, linux-2.6.10), and
should be backported to stable versions.
Reported-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Tested-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Now that we support changing the chunksize, we calculate
"reshape_sectors" to be the max of number of sectors in old
and new chunk size.
However there is one please where we still use 'chunksize'
rather than 'reshape_sectors'.
This causes a reshape that reduces the size of chunks to freeze.
Signed-off-by: NeilBrown <neilb@suse.de>
md has functionality to 'quiesce' and array so that all pending
IO completed and no new IO starts. This is used to achieve a
stable state before making internal changes.
Currently this quiescing applies equally to normal IO, resync
IO, and reshape IO.
However there is a problem with applying it to reshape IO.
Reshape can have multiple 'stripe_heads' that must be active together.
If the quiesce come between allocating the first and the last of
such a collection, then we deadlock, as the last will not be allocated
until the quiesce is lifted, the quiesce will not be lifted until the
first (which has been allocated) gets used, and that first cannot be
used until the last is allocated.
It is not necessary to inhibit reshape IO when a quiesce is
requested. Those places in the code that require a full quiesce will
ensure the reshape thread is not running at all.
So allow reshape requests to get access to new stripe_heads without
being blocked by a 'quiesce'.
This only affects in-place reshapes (i.e. where the array does not
grow or shrink) and these are only newly supported. So this patch is
not needed in earlier kernels.
Signed-off-by: NeilBrown <neilb@suse.de>
mddev->raid_disks can be changed and any time by a request from
user-space. It is a suggestion as to what number of raid_disks is
desired.
conf->raid_disks can only be changed by the raid5 module with suitable
locks in place. It is a statement as to the current number of
raid_disks.
There are two places where the latter should be used, but the former
is used. This can lead to a crash when reshaping an array.
This patch changes to mddev-> to conf->
Signed-off-by: NeilBrown <neilb@suse.de>
Our async work synchronization was broken by "async: make sure
independent async domains can't accidentally entangle" (commit
d5a877e8dd), because it would report
the wrong lowest active async ID when there was both running and
pending async work.
This caused things like no being able to read the root filesystem,
resulting in missing console devices and inability to run 'init',
causing a boot-time panic.
This fixes it by properly returning the lowest pending async ID: if
there is any running async work, that will have a lower ID than any
pending work, and we should _not_ look at the pending work list.
There were alternative patches from Jaswinder and James, but this one
also cleans up the code by removing the pointless 'ret' variable and
the unnecesary testing for an empty list around 'for_each_entry()' (if
the list is empty, the for_each_entry() thing just won't execute).
Fixes-bug: http://bugzilla.kernel.org/show_bug.cgi?id=13474
Reported-and-tested-by: Chris Clayton <chris2553@googlemail.com>
Cc: Jaswinder Singh Rajput <jaswinder@kernel.org>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Using gcc 3.3.5 a "make allmodconfig" + "CONFIG_KVM=n"
triggers a build error:
arch/x86/mm/built-in.o(.init.text+0x43f7): In function `__change_page_attr':
arch/x86/mm/pageattr.c:114: undefined reference to `__udivdi3'
make: *** [.tmp_vmlinux1] Error 1
The culprit turned out to be a division in arch/x86/mm/memtest.c
For more info see this thread:
http://marc.info/?l=linux-kernel&m=124416232620683
The patch entirely removes the division that caused the build
error.
[ Impact: build fix with certain GCC versions ]
Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: xiyou.wangcong@gmail.com
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: <stable@kernel.org>
LKML-Reference: <20090608170939.GB12431@alberich.amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix bug in the SGI UV macros that support systems with multiple
coherency domains. The macros used for referencing global MMR
(chipset registers) are failing to correctly "or" the NASID
(node identifier) bits that reside above M+N. These high bits
are supplied automatically by the chipset for memory accesses
coming from the processor socket.
However, the bits must be present for references to the special
global MMR space used to map chipset registers. (See uv_hub.h
for more details ...)
The bug results in references to invalid/incorrect nodes.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Cc: <stable@kernel.org>
LKML-Reference: <20090608154405.GA16395@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
MIPS: Outline udelay and fix a few issues.
MIPS: ioctl.h: Fix headers_check warnings
MIPS: Cobalt: PCI bus is always required to obtain the board ID
MIPS: Kconfig: Remove "Support for" from Cavium system type
MIPS: Sibyte: Honor CONFIG_CMDLINE
SSB: BCM47xx: Export ssb_watchdog_timer_set
The previous patch submission had a I typo I didn't catch but Bartlomiej
noted. Guess this proves the point about any patch being risky late in an rc
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Outlining fixes the issue were on certain CPUs such as the R10000 family
the delay loop would need an extra cycle if it overlaps a cacheline
boundary.
The rewrite also fixes build errors with GCC 4.4 which was changed in
way incompatible with the kernel's inline assembly.
Relying on pure C for computation of the delay value removes the need for
explicit. The price we pay is a slight slowdown of the computation - to
be fixed on another day.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Make ioctl.h compatible with asm-generic/ioctl.h and userspace
fix the following 'make headers_check' warning:
usr/include/asm-mips/ioctl.h:64: extern's make no sense in userspace
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
this patch export ssb_watchdog_timer_set to allow to use it in a Linux
watchdog driver.
Signed-off-by: Matthieu CASTET <castet.matthieu@free.fr>
Acked-by : Michael Buesch <mb@bu3sch.de>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* master.kernel.org:/home/rmk/linux-2.6-arm:
[ARM] 5543/1: arm: serial amba: add missing declaration in serial.h
[ARM] pxa: fix pxa27x_udc default pullup GPIO
[ARM] pxa/imote2: fix UCAM sensor board ADC model number
mx[23]: don't put clock lookups in __initdata
fix oops when using console=ttymxcN with N > 0
[ARM] ARMv7 errata: only apply fixes when running on applicable CPU
[ARM] 5534/1: kmalloc must return a cache line aligned buffer
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc:
sdhci-of: Fix the wrong accessor to HOSTVER register
mvsdio: fix config failure with some high speed SDHC cards
mvsdio: ignore high speed timing requests from the core
mmc/omap: Use disable_irq_nosync() from within irq handlers.
sdhci-of: Add fsl,esdhc as a valid compatible to bind against
mvsdio: allow automatic loading when modular
mxcmmc: Fix missing return value checking in DMA setup code.
mxcmmc : Reset the SDHC hardware if software timeout occurs.
omap_hsmmc: Trivial fix for a typo in comment
mxcmmc: decrease minimum frequency to make MMC cards work