linux-stable.git/Documentation/kernel-parameters.txt, branch linux-3.12.y

x86/platform/goldfish: Prevent unconditional loading

2017-03-01T19:27:47+00:00

commit 47512cfd0d7a8bd6ab71d01cd89fca19eb2093eb upstream.

The goldfish platform code registers the platform device unconditionally
which causes havoc in several ways if the goldfish_pdev_bus driver is
enabled:

 - Access to the hardcoded physical memory region, which is either not
   available or contains stuff which is completely unrelated.

 - Prevents that the interrupt of the serial port can be requested

 - In case of a spurious interrupt it goes into a infinite loop in the
   interrupt handler of the pdev_bus driver (which needs to be fixed
   seperately).

Add a 'goldfish' command line option to make the registration opt-in when
the platform is compiled in.

I'm seriously grumpy about this engineering trainwreck, which has seven
SOBs from Intel developers for 50 lines of code. And none of them figured
out that this is broken. Impressive fail!

Fixes: ddd70cf93d78 ("goldfish: platform device for x86")
Reported-by: Gabriel C 
Signed-off-by: Thomas Gleixner 
Acked-by: Linus Torvalds 
Signed-off-by: Jiri Slaby

Input: i8042 - reset keyboard to fix Elantech touchpad detection

2015-01-29T14:44:42+00:00

commit 148e9a711e034e06310a8c36b64957934ebe30f2 upstream.

On some laptops, keyboard needs to be reset in order to successfully detect
touchpad (e.g., some Gigabyte laptop models with Elantech touchpads).
Without resettin keyboard touchpad pretends to be completely dead.

Based on the original patch by Mateusz Jończyk this version has been
expanded to include DMI based detection & application of the fix
automatically on the affected models of laptops. This has been confirmed to
fix problem by three users already on three different models of laptops.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=81331
Signed-off-by: Srihari Vijayaraghavan 
Acked-by: Mateusz Jończyk 
Tested-by: Srihari Vijayaraghavan 
Tested by: Zakariya Dehlawi 
Tested-by: Guillaum Bouchard 
Signed-off-by: Dmitry Torokhov 
Signed-off-by: Jiri Slaby

ACPI / memhotplug: add parameter to disable memory hotplug

2014-06-27T08:25:16+00:00

commit 00159a2013269bc0a617de885e4b921349192bd0 upstream.

When booting a kexec/kdump kernel on a system that has specific memory
hotplug regions the boot will fail with warnings like:

 swapper/0: page allocation failure: order:9, mode:0x84d0
 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.10.0-65.el7.x86_64 #1
 Hardware name: QCI QSSC-S4R/QSSC-S4R, BIOS QSSC-S4R.QCI.01.00.S013.032920111005 03/29/2011
  0000000000000000 ffff8800341bd8c8 ffffffff815bcc67 ffff8800341bd950
  ffffffff8113b1a0 ffff880036339b00 0000000000000009 00000000000084d0
  ffff8800341bd950 ffffffff815b87ee 0000000000000000 0000000000000200
 Call Trace:
  [] dump_stack+0x19/0x1b
  [] warn_alloc_failed+0xf0/0x160
  [] ?  __alloc_pages_direct_compact+0xac/0x196
  [] __alloc_pages_nodemask+0x7ff/0xa00
  [] vmemmap_alloc_block+0x62/0xba
  [] vmemmap_alloc_block_buf+0x15/0x3b
  [] vmemmap_populate+0xb4/0x21b
  [] sparse_mem_map_populate+0x27/0x35
  [] sparse_add_one_section+0x7a/0x185
  [] __add_pages+0xaf/0x240
  [] arch_add_memory+0x59/0xd0
  [] add_memory+0xb9/0x1b0
  [] acpi_memory_device_add+0x18d/0x26d
  [] acpi_bus_device_attach+0x7d/0xcd
  [] acpi_ns_walk_namespace+0xc8/0x17f
  [] ? acpi_bus_type_and_status+0x90/0x90
  [] ? acpi_bus_type_and_status+0x90/0x90
  [] acpi_walk_namespace+0x95/0xc5
  [] acpi_bus_scan+0x8b/0x9d
  [] acpi_scan_init+0x63/0x160
  [] acpi_init+0x25d/0x2a6
  [] ? acpi_sleep_proc_init+0x2a/0x2a
  [] do_one_initcall+0xe2/0x190
  [] kernel_init_freeable+0x17c/0x207
  [] ? do_early_param+0x88/0x88
  [] ? rest_init+0x80/0x80
  [] kernel_init+0xe/0x180
  [] ret_from_fork+0x7c/0xb0
  [] ? rest_init+0x80/0x80
 Mem-Info:
 Node 0 DMA per-cpu:
 CPU    0: hi:    0, btch:   1 usd:   0
 Node 0 DMA32 per-cpu:
 CPU    0: hi:   42, btch:   7 usd:   0
 active_anon:0 inactive_anon:0 isolated_anon:0
  active_file:0 inactive_file:0 isolated_file:0
  unevictable:0 dirty:0 writeback:0 unstable:0
  free:872 slab_reclaimable:13 slab_unreclaimable:1880
  mapped:0 shmem:0 pagetables:0 bounce:0
  free_cma:0

because the system has run out of memory at boot time.  This occurs
because of the following sequence in the boot:

Main kernel boots and sets E820 map.  The second kernel is booted with a
map generated by the kdump service using memmap= and memmap=exactmap.
These parameters are added to the kernel parameters of the kexec/kdump
kernel.   The kexec/kdump kernel has limited memory resources so as not
to severely impact the main kernel.

The system then panics and the kdump/kexec kernel boots (which is a
completely new kernel boot).  During this boot ACPI is initialized and the
kernel (as can be seen above) traverses the ACPI namespace and finds an
entry for a memory device to be hotadded.

ie)

  [] __add_pages+0xaf/0x240
  [] arch_add_memory+0x59/0xd0
  [] add_memory+0xb9/0x1b0
  [] acpi_memory_device_add+0x18d/0x26d
  [] acpi_bus_device_attach+0x7d/0xcd
  [] acpi_ns_walk_namespace+0xc8/0x17f
  [] ? acpi_bus_type_and_status+0x90/0x90
  [] ? acpi_bus_type_and_status+0x90/0x90
  [] acpi_walk_namespace+0x95/0xc5
  [] acpi_bus_scan+0x8b/0x9d
  [] acpi_scan_init+0x63/0x160
  [] acpi_init+0x25d/0x2a6

At this point the kernel adds page table information and the the kexec/kdump
kernel runs out of memory.

This can also be reproduced by using the memmap=exactmap and mem=X
parameters on the main kernel and booting.

This patchset resolves the problem by adding a kernel parameter,
acpi_no_memhotplug, to disable ACPI memory hotplug.

Signed-off-by: Prarit Bhargava 
Acked-by: Vivek Goyal 
Acked-by: Toshi Kani 
Acked-by: David Rientjes 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Jiri Slaby

libata: disable a disk via libata.force params

2014-01-09T20:25:12+00:00

commit b8bd6dc36186fe99afa7b73e9e2d9a98ad5c4865 upstream.

A user on StackExchange had a failing SSD that's soldered directly
onto the motherboard of his system. The BIOS does not give any option
to disable it at all, so he can't just hide it from the OS via the
BIOS.

The old IDE layer had hdX=noprobe override for situations like this,
but that was never ported to the libata layer.

This patch implements a disable flag for libata.force.

Example use:

 libata.force=2.0:disable

[v2 of the patch, removed the nodisable flag per Tejun Heo]

Signed-off-by: Robin H. Johnson 
Signed-off-by: Tejun Heo 
Link: http://unix.stackexchange.com/questions/102648/how-to-tell-linux-kernel-3-0-to-completely-ignore-a-failing-disk
Link: http://askubuntu.com/questions/352836/how-can-i-tell-linux-kernel-to-completely-ignore-a-disk-as-if-it-was-not-even-co
Link: http://superuser.com/questions/599333/how-to-disable-kernel-probing-for-drive
Signed-off-by: Greg Kroah-Hartman

block: change config option name for cmdline partition parsing

2013-09-30T21:31:02+00:00

Recently commit bab55417b10c ("block: support embedded device command
line partition") introduced CONFIG_CMDLINE_PARSER.  However, that name
is too generic and sounds like it enables/disables generic kernel boot
arg processing, when it really is block specific.

Before this option becomes a part of a full/final release, add the BLK_
prefix to it so that it is clear in absence of any other context that it
is block specific.

In addition, fix up the following less critical items:
 - help text was not really at all helpful.
 - index file for Documentation was not updated
 - add the new arg to Documentation/kernel-parameters.txt
 - clarify wording in source comments

Signed-off-by: Paul Gortmaker 
Cc: Jens Axboe 
Cc: Cai Zhiyong 
Cc: Wei Yongjun 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Documentation/kernel-parameters.txt: replace kernelcore with Movable

2013-09-30T21:31:02+00:00

Han Pingtian found a typo in Documentation/kernel-parameters.txt about
"kernelcore=", that "kernelcore" should be replaced with "Movable" here.

Signed-off-by: Weiping Pan 
Acked-by: Mel Gorman 
Cc: Randy Dunlap 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge tag 'stable/for-linus-3.12-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

2013-09-25T22:50:53+00:00

Pull Xen fixes from Konrad Rzeszutek Wilk:
 "Bug-fixes and one update to the kernel-paramters.txt documentation.

   - Fix PV spinlocks triggering jump_label code bug
   - Remove extraneous code in the tpm front driver
   - Fix ballooning out of pages when non-preemptible
   - Fix deadlock when using a 32-bit initial domain with large amount
     of memory
   - Add xen_nopvpsin parameter to the documentation"

* tag 'stable/for-linus-3.12-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/spinlock: Document the xen_nopvspin parameter.
  xen/p2m: check MFN is in range before using the m2p table
  xen/balloon: don't alloc page while non-preemptible
  xen: Do not enable spinlocks before jump_label_init() has executed
  tpm: xen-tpmfront: Remove the locality sysfs attribute
  tpm: xen-tpmfront: Fix default durations

xen/spinlock: Document the xen_nopvspin parameter.

2013-09-25T14:07:34+00:00

Which disables in the ticketlock slowpath the Xen PV optimization's.
Useful for diagnosing issues and comparing benchmarks in
over-commit CPU scenarios.

Signed-off-by: Konrad Rzeszutek Wilk

Merge tag 'nfs-for-3.12-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

2013-09-09T16:19:15+00:00

Pull NFS client updates from Trond Myklebust:
"Highlights include:

- Fix NFSv4 recovery so that it doesn't recover lost locks in cases
such as lease loss due to a network partition, where doing so may
result in data corruption. Add a kernel parameter to control
choice of legacy behaviour or not.
- Performance improvements when 2 processes are writing to the same
file.
- Flush data to disk when an RPCSEC_GSS session timeout is imminent.
- Implement NFSv4.1 SP4_MACH_CRED state protection to prevent other
NFS clients from being able to manipulate our lease and file
locking state.
- Allow sharing of RPCSEC_GSS caches between different rpc clients.
- Fix the broken NFSv4 security auto-negotiation between client and
server.
- Fix rmdir() to wait for outstanding sillyrename unlinks to complete
- Add a tracepoint framework for debugging NFSv4 state recovery
issues.
- Add tracing to the generic NFS layer.
- Add tracing for the SUNRPC socket connection state.
- Clean up the rpc_pipefs mount/umount event management.
- Merge more patches from Chuck in preparation for NFSv4 migration
support"

* tag 'nfs-for-3.12-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (107 commits)
NFSv4: use mach cred for SECINFO_NO_NAME w/ integrity
NFS: nfs_compare_super shouldn't check the auth flavour unless 'sec=' was set
NFSv4: Allow security autonegotiation for submounts
NFSv4: Disallow security negotiation for lookups when 'sec=' is specified
NFSv4: Fix security auto-negotiation
NFS: Clean up nfs_parse_security_flavors()
NFS: Clean up the auth flavour array mess
NFSv4.1 Use MDS auth flavor for data server connection
NFS: Don't check lock owner compatability unless file is locked (part 2)
NFS: Don't check lock owner compatibility in writes unless file is locked
nfs4: Map NFS4ERR_WRONG_CRED to EPERM
nfs4.1: Add SP4_MACH_CRED write and commit support
nfs4.1: Add SP4_MACH_CRED stateid support
nfs4.1: Add SP4_MACH_CRED secinfo support
nfs4.1: Add SP4_MACH_CRED cleanup support
nfs4.1: Add state protection handler
nfs4.1: Minimal SP4_MACH_CRED implementation
SUNRPC: Replace pointer values with task->tk_pid and rpc_clnt->cl_clid
SUNRPC: Add an identifier for struct rpc_clnt
SUNRPC: Ensure rpc_task->tk_pid is available for tracepoints
...

NFSv4: Document the recover_lost_locks kernel parameter

2013-09-04T16:26:32+00:00

Rename the new 'recover_locks' kernel parameter to 'recover_lost_locks'
and change the default to 'false'. Document why in
Documentation/kernel-parameters.txt

Move the 'recover_lost_locks' kernel parameter to fs/nfs/super.c to
make it easy to backport to kernels prior to 3.6.x, which don't have
a separate NFSv4 module.

Signed-off-by: Trond Myklebust