Revert "ACPI / EC: Add support to disallow QR_EC to be issued before completing previous QR_EC"

It is reported that the following commit breaks Samsung hardware:
 Commit: 558e4736f2e1b0e6323adf7a5e4df77ed6cfc1a4.
 Subject: ACPI / EC: Add support to disallow QR_EC to be issued before
          completing previous QR_EC

Which means the Samsung behavior conflicts with the Acer behavior.

1. Samsung may behave like:
   [ +event 1 ] SCI_EVT set
   [ +event 2 ] SCI_EVT set
                              write QR_EC
                              read event
   [ -event 1 ] SCI_EVT clear
   Without the above commit, Samsung can work:
   [ +event 1 ] SCI_EVT set
   [ +event 2 ] SCI_EVT set
                              write QR_EC
                              CAN prepare next QR_EC as SCI_EVT=1
                              read event
   [ -event 1 ] SCI_EVT clear
                              write QR_EC
                              read event
   [ -event 2 ] SCI_EVT clear
   With the above commit, Samsung cannot work:
   [ +event 1 ] SCI_EVT set
   [ +event 2 ] SCI_EVT set
                              write QR_EC
                              read event
   [ -event 1 ] SCI_EVT clear
                              CANNOT prepare next QR_EC as SCI_EVT=0
2. Acer may behave like:
   [ +event 1 ] SCI_EVT set
   [ +event 2 ]
                              write QR_EC
                              read event
   [ -event 1 ] SCI_EVT clear
   [ +event 2 ] SCI_EVT set
   Without the above commit, Acer cannot work when there is only 1 event:
   [ +event 1 ] SCI_EVT set
                              write QR_EC
                              can prepared next QR_EC as SCI_EVT=1
                              read event
   [ -event 1 ] SCI_EVT clear
                              CANNOT write QR_EC as SCI_EVT=0
   With the above commit, Acer can work:
   [ +event 1 ] SCI_EVT set
   [ +event 2 ]
                              write QR_EC
                              read event
   [ -event 1 ] SCI_EVT set
                              can prepare next QR_EC because SCI_EVT=0
                              CAN write QR_EC as SCI_EVT=1

Since Acer can also work with only the following commit applied:
 Commit: 3afcf2ece453e1a8c2c6de19cdf06da3772a1b08
 Subject: ACPI / EC: Add support to disallow QR_EC to be issued when
          SCI_EVT isn't set
commit 558e4736f2e1b0e6323adf7a5e4df77ed6cfc1a4 can be reverted.

Fixes: 558e4736f2e1 (ACPI / EC: Add support to disallow QR_EC to be issued ...)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=44161
Reported-and-tested-by: Ortwin Glück <odi@odi.ch>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Cc: 3.17+ <stable@vger.kernel.org> # 3.17+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
ACPI / EC: Fix regression due to conflicting firmware behavior between Samsung and Acer.

It is reported that Samsung laptops that need to poll events are broken by
the following commit:
 Commit 3afcf2ece453e1a8c2c6de19cdf06da3772a1b08
 Subject: ACPI / EC: Add support to disallow QR_EC to be issued when SCI_EVT isn't set

The behaviors of the 2 vendor firmwares are conflict:
 1. Acer: OSPM shouldn't issue QR_EC unless SCI_EVT is set, firmware
         automatically sets SCI_EVT as long as there is event queued up.
 2. Samsung: OSPM should issue QR_EC whatever SCI_EVT is set, firmware
            returns 0 when there is no event queued up.

This patch is a quick fix to distinguish the behaviors to make Acer
behavior only effective for Acer EC firmware so that the breakages on
Samsung EC firmware can be avoided.

Fixes: 3afcf2ece453 (ACPI / EC: Add support to disallow QR_EC to be issued ...)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=44161
Reported-and-tested-by: Ortwin Glück <odi@odi.ch>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Cc: 3.17+ <stable@vger.kernel.org> # 3.17+
[ rjw : Subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
PCI: imx6: Wait for clocks to stabilize after ref_en

For boards without a reset GPIO we skip the delay between enabling the
pcie_ref_clk and touching the RC registers for configuration.  This hangs
the system if there isn't a proper delay to ensure the clocks are settled
in the DW PCIe core.

Also iMX6Q always needs an additional 10us delay to make sure the reset is
propagated through the core, as we don't have an explicitly controlled
reset input on this SoC.

This fixes a problem with 3fce0e882f61 ("PCI: imx6: Delay enabling
reference clock for SS until it stabilizes"): the kernel doesn't boot on
systems that don't pass the PCI GPIO reset in the DTB.  This regression
affects mx6 nitrogen boards.

[bhelgaas: add regression info in changelog]
Fixes: 3fce0e882f61 ("PCI: imx6: Delay enabling reference clock for SS until it stabilizes")
Reported-by: Fabio Estevam <fabio.estevam@freescale.com>
Tested-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Richard Zhu <richard.zhu@freescale.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Lucas Stach <l.stach@pengutronix.de>
drm/radeon: remove some buggy dead code

The calculation of "num_shader_engines" has a precedence bug because
the right shift happens before the mask, but this variable is never used
so we can just delete it.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Merge tag 'usb-serial-3.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/johan/usb-serial into usb-linus

Johan writes:

USB-serial fixes for v3.18-rc3

These updates remove two allocations of unused buffers from kobil_sct
and add some new device ids.

Signed-off-by: Johan Hovold <johan@kernel.org>
ARM: 8181/1: Drop extra return statement

Commit 513510ddba9650fc7da456eefeb0ead7632324f6
(common: dma-mapping: introduce common remapping functions)
managed to end up with an extra return statement from the
original patch. Drop it.

Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 8183/1: l2c: Improve l2c310_of_parse() error message

Russell King suggested [1]:

"I'd ask for one change.  Please make all these messages start with
"L2C-310 OF" not "PL310 OF:".  The device is described in ARM
documentation as a L2C-310 not PL310.  (Also note the : is dropped
too - most of the other messages don't have the : either.)

The:

"PL310 OF: cache setting yield illegal associativity
PL310 OF: -1073346556 calculated, only 8 and 16 legal"

message could also be changed to something like:

"L2C-310 OF cache associativity %d invalid, only 8 or 16 permittedn"

[1] http://www.spinics.net/lists/arm-kernel/msg372776.html

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 8180/1: mm: implement no-highmem fast path in kmap_atomic_pfn()

Since CONFIG_HIGHMEM got enabled on ARMv5 Kirkwood, we have noticed a
very significant drop in networking performance. The test were
conducted on an OpenBlocks A7 board. Without this patch, the outgoing
performance measured with iperf are:

 - highmem OFF, TSO OFF   544 Mbit/s
 - highmem OFF, TSO ON	  942 Mbit/s
 - highmem ON,  TSO OFF   306 Mbit/s
 - highmem ON,  TSO ON    246 Mbit/s

On this Kirkwood platform, the L2 cache is a Feroceon cache, and with
this cache, all the range operations have to be done on virtual
addresses and not physical addresses. Therefore, whenever
CONFIG_HIGHMEM is enabled, the cache maintenance operations call
kmap_atomic_pfn() and kunmap_atomic().

However, kmap_atomic_pfn() does not implement the same fast path for
non-highmem pages as the one implemented in kmap_atomic(), and this is
one of the reason for the performance drop. While this patch does not
fully restore the performances, it clearly improves them a lot:

      	      	        without patch  with patch

 - highmem ON, TSO OFF   306 Mbit/s     387 Mbit/s
 - highmem ON, TSO ON    246 Mbit/s     434 Mbit/s

We're still far from the !CONFIG_HIGHMEM performances, but it does
improve a bit the situation.

Thanks a lot to Ezequiel Garcia and Gregory Clement for all the
testing work around this topic.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux

Pull powerpc updates from Michael Ellerman:
 "There's some bug fixes or cleanups to facilitate fixes, a MAINTAINERS
  update, and a new syscall (bpf)"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux:
  powerpc/numa: ensure per-cpu NUMA mappings are correct on topology update
  powerpc/numa: use cached value of update->cpu in update_cpu_topology
  cxl: Fix PSL error due to duplicate segment table entries
  powerpc/mm: Use appropriate ESID mask in copro_calculate_slb()
  cxl: Refactor cxl_load_segment() and find_free_sste()
  cxl: Disable secondary hash in segment table
  Revert "powerpc/powernv: Fix endian bug in LPC bus debugfs accessors"
  powernv: Use _GLOBAL_TOC for opal wrappers
  powerpc: Wire up sys_bpf() syscall
  MAINTAINERS: nx-842 driver maintainer change
  powerpc/mm: Remove redundant #if case
  powerpc/mm: Fix build error with hugetlfs disabled
sch_pie: schedule the timer after all init succeed

Cc: Vijay Subramanian <vijaynsu@cisco.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
ipv6: notify userspace when we added or changed an ipv6 token

NetworkManager might want to know that it changed when the router advertisement
arrives.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

Pull Integrity subsystem fix from James Morris:
 "These changes fix a bug in xattr handling, where the evm and ima
  inode_setxattr() functions do not check for empty xattrs being passed
  from userspace (leading to user-triggerable null pointer
  dereferences)"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  evm: check xattr value length and type in evm_inode_setxattr()
  ima: check xattr value length and type in the ima_inode_setxattr()
cxgb4vf: Replace repetitive pci device ID's with right ones

Replaced repetive Device ID's which got added in commit b961f9a48844ecf3
("cxgb4vf: Remove superfluous "idx" parameter of CH_DEVICE() macro")

Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid

Pull HID fixes from Jiri Kosina:
 - workarounds for a couple of misbehaving Elan Touchscreens, by Adel
   Gadllah
 - fix for TransducerSerialNumber field implementation, by Jason Gerecke
 - a couple of new HID usages (added by HUT), by Olivier Gay

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
  HID: input: Fix TransducerSerialNumber implementation
  HID: add keyboard input assist hid usages
  HID: usbhid: enable always-poll quirk for Elan Touchscreen 016f
  HID: usbhid: enable always-poll quirk for Elan Touchscreen 009b
dm raid: fix inaccessible superblocks causing oops in configure_discard_support

Commit 48cf06bc5f ("dm raid: add discard support for RAID levels 4, 5
and 6") did not properly handle missing metadata device(s).  A failing
read of the superblock causes the metadata and data devices to be
removed from the dev array in struct raid_set, setting references to
both devices to NULL.  configure_discard_support() nonetheless tries to
access the data dev unconditionally causing an oops.

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Merge branch 'for-linus' of git://git.kernel.dk/linux-block

Pull block layer fixes from Jens Axboe:
 "A small collection of fixes for the current kernel.  This contains:

   - Two error handling fixes from Jan Kara.  One for null_blk on
     failure to add a device, and the other for the block/scsi_ioctl
     SCSI_IOCTL_SEND_COMMAND fixing up the error jump point.

   - A commit added in the merge window for the bio integrity bits
     unfortunately disabled merging for all requests if
     CONFIG_BLK_DEV_INTEGRITY wasn't set.  Reverse the logic, so that
     integrity checking wont disallow merges when not enabled.

   - A fix from Ming Lei for merging and generating too many segments.
     This caused a BUG in virtio_blk.

   - Two error handling printk() fixups from Robert Elliott, improving
     the information given when we rate limit.

   - Error handling fixup on elevator_init() failure from Sudip
     Mukherjee.

   - A fix from Tony Battersby, fixing up a memory leak in the
     scatterlist handling with scsi-mq"

* 'for-linus' of git://git.kernel.dk/linux-block:
  block: Fix merge logic when CONFIG_BLK_DEV_INTEGRITY is not defined
  lib/scatterlist: fix memory leak with scsi-mq
  block: fix wrong error return in elevator_init()
  scsi: Fix error handling in SCSI_IOCTL_SEND_COMMAND
  null_blk: Cleanup error recovery in null_add_dev()
  blk-merge: recaculate segment if it isn't less than max segments
  fs: clarify rate limit suppressed buffer I/O errors
  fs: merge I/O error prints into one line
cnic: Update the rcu_access_pointer() usages

1. Remove the rcu_read_lock/unlock around rcu_access_pointer
2. Replace the rcu_dereference with rcu_access_pointer

Signed-off-by: Tej Parkash <tej.parkash@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ARM: omap2plus_defconfig: Fix errors with NAND BCH

Looks like we need to have BCH enabled to get NAND
working and to avoid getting:

nand: error: CONFIG_MTD_NAND_ECC_BCH not enabled

Signed-off-by: Tony Lindgren <tony@atomide.com>
ARM: OMAP2+: Warn about deprecated legacy booting mode

We're moving omaps to use device tree based booting and already have
omap2, omap4, omap5, am335x and am437x booting in device tree only
mode.

Only omap3 still has legacy booting still around and we really want
to make that device tree only. So let's add a warning about deprecated
legacy booting so we get people to upgrade their boards to use device
tree based booting and find out about any remaining issues.

Note that for most boards we already have the .dts file and those can
be booted with without changing the bootloader using the appended
DTB mode.

Acked-By: Sebastian Reichel <sre@kernel.org>
Reviewed-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Reviewed-by: Javier Martinez Canillas <javier@dowhile0.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
inet: frags: fix a race between inet_evict_bucket and inet_frag_kill

When the evictor is running it adds some chosen frags to a local list to
be evicted once the chain lock has been released but at the same time
the *frag_queue can be running for some of the same queues and it
may call inet_frag_kill which will wait on the chain lock and
will then delete the queue from the wrong list since it was added in the
eviction one. The fix is simple - check if the queue has the evict flag
set under the chain lock before deleting it, this is safe because the
evict flag is set only under that lock and having the flag set also means
that the queue has been detached from the chain list, so no need to delete
it again.
An important note to make is that we're safe w.r.t refcnt because
inet_frag_kill and inet_evict_bucket will sync on the del_timer operation
where only one of the two can succeed (or if the timer is executing -
none of them), the cases are:
1. inet_frag_kill succeeds in del_timer
 - then the timer ref is removed, but inet_evict_bucket will not add
   this queue to its expire list but will restart eviction in that chain
2. inet_evict_bucket succeeds in del_timer
 - then the timer ref is kept until the evictor "expires" the queue, but
   inet_frag_kill will remove the initial ref and will set
   INET_FRAG_COMPLETE which will make the frag_expire fn just to remove
   its ref.
In the end all of the queue users will do an inet_frag_put and the one
that reaches 0 will free it. The refcount balance should be okay.

CC: Florian Westphal <fw@strlen.de>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: Patrick McLean <chutzpah@gentoo.org>

Fixes: b13d3cbfb8e8 ("inet: frag: move eviction of queues to work queue")
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Reported-by: Patrick McLean <chutzpah@gentoo.org>
Tested-by: Patrick McLean <chutzpah@gentoo.org>
Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>