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  1. 23 Jan, 2015 2 commits
    • Thomas Gleixner's avatar
      hrtimer: Prevent stale expiry time in hrtimer_interrupt() · 9bc74919
      Thomas Gleixner authored 
      hrtimer_interrupt() has the following subtle issue:

hrtimer_interrupt()
  lock(cpu_base);
  expires_next = KTIME_MAX;

  expire_timers(CLOCK_MONOTONIC);
  expires = get_next_timer(CLOCK_MONOTONIC);
  if (expires < expires_next)
    expires_next = expires;

  expire_timers(CLOCK_REALTIME);
    unlock(cpu_base);
    wakeup()
    hrtimer_start(CLOCK_MONOTONIC, newtimer);
    lock(cpu_base();  
  expires = get_next_timer(CLOCK_REALTIME);
  if (expires < expires_next)
    expires_next = expires;

So because we already evaluated the next expiring timer of
CLOCK_MONOTONIC we ignore that the expiry time of newtimer might be
earlier than the overall next expiry time in hrtimer_interrupt().

To solve this, remove the caching of the next expiry value from
hrtimer_interrupt() and reevaluate all active clock bases for the next
expiry value. To avoid another code duplication, create a shared
evaluation function and use it for hrtimer_get_next_event(),
hrtimer_force_reprogram() and hrtimer_interrupt().

There is another subtlety in this mechanism:

While hrtimer_interrupt() is running, we want to avoid to touch the
hardware device because we will reprogram it anyway at the end of
hrtimer_interrupt(). This works nicely for hrtimers which get rearmed
via the HRTIMER_RESTART mechanism, because we drop out when the
callback on that CPU is running. But that fails, if a new timer gets
enqueued like in the example above.

This has another implication: While hrtimer_interrupt() is running we
refuse remote enqueueing of timers - see hrtimer_interrupt() and
hrtimer_check_target().

hrtimer_interrupt() tries to prevent this by setting cpu_base->expires
to KTIME_MAX, but that fails if a new timer gets queued.

Prevent both the hardware access and the remote enqueue
explicitely. We can loosen the restriction on the remote enqueue now
due to reevaluation of the next expiry value, but that needs a
seperate patch.

Folded in a fix from Vignesh Radhakrishnan.
Reported-and-tested-by: default avatarStanislav Fomichev <stfomichev@yandex-team.ru>
Based-on-patch-by: default avatarStanislav Fomichev <stfomichev@yandex-team.ru>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: vigneshr@codeaurora.org
Cc: john.stultz@linaro.org
Cc: viresh.kumar@linaro.org
Cc: fweisbec@gmail.com
Cc: cl@linux.com
Cc: stuart.w.hayes@gmail.com
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1501202049190.5526@nanosSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      9bc74919
    • Chunyan Zhang's avatar
      ktime.h: Introduce ktime_ms_delta · 41fbf3b3
      Chunyan Zhang authored 
      This patch adds a reusable time difference function which returns the
difference in millisecond, as often used in some driver code, e.g.
mtd/test, media/rc, etc.
Signed-off-by: default avatarChunyan Zhang <zhang.chunyan@linaro.org>
Acked-by: default avatarArnd Bergmann <arnd@linaro.org>
Cc: zhang.lyra@gmail.com
Cc: davem@davemloft.net
Cc: john.stultz@linaro.org
Cc: dborkman@redhat.com
Link: http://lkml.kernel.org/r/1418793095-18780-1-git-send-email-zhang.chunyan@linaro.orgSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      41fbf3b3
  3. 18 Jan, 2015 4 commits
    • Linus Torvalds's avatar
      Linux 3.19-rc5 · ec6f34e5
      Linus Torvalds authored
      ec6f34e5
    • Linus Torvalds's avatar
      Merge tag 'armsoc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc · d0ac5d8e
      Linus Torvalds authored 
      Pull ARM SoC fixes from Olof Johansson:
 "We've been sitting on our fixes branch for a while, so this batch is
  unfortunately on the large side.

  A lot of these are tweaks and fixes to device trees, fixing various
  bugs around clocks, reg ranges, etc.  There's also a few defconfig
  updates (which are on the late side, no more of those).

  All in all the diffstat is bigger than ideal at this time, but nothing
  in here seems particularly risky"

* tag 'armsoc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (31 commits)
  reset: sunxi: fix spinlock initialization
  ARM: dts: disable CCI on exynos5420 based arndale-octa
  drivers: bus: check cci device tree node status
  ARM: rockchip: disable jtag/sdmmc autoswitching on rk3288
  ARM: nomadik: fix up leftover device tree pins
  ARM: at91: board-dt-sama5: add phy_fixup to override NAND_Tree
  ARM: at91/dt: sam9263: Add missing clocks to lcdc node
  ARM: at91: sama5d3: dt: correct the sound route
  ARM: at91/dt: sama5d4: fix the timer reg length
  ARM: exynos_defconfig: Enable LM90 driver
  ARM: exynos_defconfig: Enable options for display panel support
  arm: dts: Use pmu_system_controller phandle for dp phy
  ARM: shmobile: sh73a0 legacy: Set .control_parent for all irqpin instances
  ARM: dts: berlin: correct BG2Q's SM GPIO location.
  ARM: dts: berlin: add broken-cd and set bus width for eMMC in Marvell DMP DT
  ARM: dts: berlin: fix io clk and add missing core clk for BG2Q sdhci2 host
  ARM: dts: Revert disabling of smc91x for n900
  ARM: dts: imx51-babbage: Fix ULPI PHY reset modelling
  ARM: dts: dra7-evm: fix qspi device tree partition size
  ARM: omap2plus_defconfig: use CONFIG_CPUFREQ_DT
  ...
      d0ac5d8e
    • Linus Torvalds's avatar
      Merge tag 'clk-fixes-for-linus' of git://git.linaro.org/people/mike.turquette/linux · 12ba8571
      Linus Torvalds authored 
      Pull clock driver fixes from Mike Turquette:
 "Small number of fixes for clock drivers and a single null pointer
  dereference fix in the framework core code.

  The driver fixes vary from fixing section mismatch warnings to
  preventing machines from hanging (and preventing developers from
  crying)"

* tag 'clk-fixes-for-linus' of git://git.linaro.org/people/mike.turquette/linux:
  clk: fix possible null pointer dereference
  Revert "clk: ppc-corenet: Fix Section mismatch warning"
  clk: rockchip: fix deadlock possibility in cpuclk
  clk: berlin: bg2q: remove non-exist "smemc" gate clock
  clk: at91: keep slow clk enabled to prevent system hang
  clk: rockchip: fix rk3288 cpuclk core dividers
  clk: rockchip: fix rk3066 pll lock bit location
  clk: rockchip: Fix clock gate for rk3188 hclk_emem_peri
  clk: rockchip: add CLK_IGNORE_UNUSED flag to fix rk3066/rk3188 USB Host
      12ba8571
    • Linus Torvalds's avatar
      Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi · 901b2082
      Linus Torvalds authored 
      Pull SCSI fixes from James Bottomley:
 "This is one fix for a Multiqueue sleeping in invalid context problem
  and a MAINTAINER file update for Qlogic"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: ->queue_rq can't sleep
  MAINTAINERS: Update maintainer list for qla4xxx
      901b2082
  5. 17 Jan, 2015 18 commits
  7. 16 Jan, 2015 16 commits
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