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  1. 28 Aug, 2015 1 commit
  3. 31 Jul, 2015 3 commits
    • Jon Hunter's avatar
      PM / Domains: Return -EPROBE_DEFER if we fail to init or turn-on domain · 311fa6ad
      Jon Hunter authored 
      When a device is probed, the function dev_pm_domain_attach() is called
to see if there is a power-domain that is associated with the device and
needs to be turned on. If dev_pm_domain_attach() does not return
-EPROBE_DEFER then the device will be probed.

For devices using genpd, dev_pm_domain_attach() will call
genpd_dev_pm_attach(). If genpd_dev_pm_attach() does not find a power
domain associated with the device then it returns an error code not
equal to -EPROBE_DEFER to allow the device to be probed. However, if
genpd_dev_pm_attach() does find a power-domain that is associated with
the device, then it does not return -EPROBE_DEFER on failure and hence
the device will still be probed. Furthermore, genpd_dev_pm_attach() does
not check the error code returned by pm_genpd_poweron() to see if the
power-domain was turned on successfully.

Fix this by checking the return code from pm_genpd_poweron() and
returning -EPROBE_DEFER from genpd_dev_pm_attach on failure, if there
is a power-domain associated with the device.
Signed-off-by: default avatarJon Hunter <jonathanh@nvidia.com>
Acked-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
Acked-by: default avatarKevin Hilman <khilman@linaro.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      311fa6ad
    • Geert Uytterhoeven's avatar
      PM / Domains: Correct unit address in power-controller example · 885fb909
      Geert Uytterhoeven authored 
      In example 2 of the generic PM domains DT bindings, the unit address of
the device node representing the child power controller doesn't match
its "reg" property. Correct it.
Signed-off-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Acked-by: default avatarKevin Hilman <khilman@linaro.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      885fb909
    • Ulf Hansson's avatar
      PM / Domains: Remove intermediate states from the power off sequence · ba2bbfbf
      Ulf Hansson authored 
      Genpd's ->runtime_suspend() (assigned to pm_genpd_runtime_suspend())
doesn't immediately walk the hierarchy of ->runtime_suspend() callbacks.
Instead, pm_genpd_runtime_suspend() calls pm_genpd_poweroff() which
postpones that until *all* the devices in the genpd are runtime suspended.

When pm_genpd_poweroff() discovers that the last device in the genpd is
about to be runtime suspended, it calls __pm_genpd_save_device() for *all*
the devices in the genpd sequentially. Furthermore,
__pm_genpd_save_device() invokes the ->start() callback, walks the
hierarchy of the ->runtime_suspend() callbacks and invokes the ->stop()
callback. This causes a "thundering herd" problem.

Let's address this issue by having pm_genpd_runtime_suspend() immediately
walk the hierarchy of the ->runtime_suspend() callbacks, instead of
postponing that to the power off sequence via pm_genpd_poweroff(). If the
selected ->runtime_suspend() callback doesn't return an error code, call
pm_genpd_poweroff() to see if it's feasible to also power off the PM
domain.

Adopting this change enables us to simplify parts of the code in genpd,
for example the locking mechanism. Additionally, it gives some positive
side effects, as described below.

i)
One device's ->runtime_resume() latency is no longer affected by other
devices' latencies in a genpd.

The complexity genpd has to support the option to abort the power off
sequence suffers from latency issues. More precisely, a device that is
requested to be runtime resumed, may end up waiting for
__pm_genpd_save_device() to complete its operations for *another* device.
That's because pm_genpd_poweroff() can't confirm an abort request while it
waits for __pm_genpd_save_device() to return.

As this patch removes the intermediate states in pm_genpd_poweroff() while
powering off the PM domain, we no longer need the ability to abort that
sequence.

ii)
Make pm_runtime[_status]_suspended() reliable when used with genpd.

Until the last device in a genpd becomes idle, pm_genpd_runtime_suspend()
will return 0 without actually walking the hierarchy of the
->runtime_suspend() callbacks. However, by returning 0 the runtime PM core
considers the device as runtime_suspended, so
pm_runtime[_status]_suspended() will return true, even though the device
isn't (yet) runtime suspended.

After this patch, since pm_genpd_runtime_suspend() immediately walks the
hierarchy of the ->runtime_suspend() callbacks,
pm_runtime[_status]_suspended() will accurately reflect the status of the
device.

iii)
Enable fine-grained PM through runtime PM callbacks in drivers/subsystems.

There are currently cases were drivers/subsystems implements runtime PM
callbacks to deploy fine-grained PM (e.g. gate clocks, move pinctrl to
power-save state, etc.). While using the genpd, pm_genpd_runtime_suspend()
postpones invoking these callbacks until *all* the devices in the genpd
are runtime suspended. In essence, one runtime resumed device prevents
fine-grained PM for other devices within the same genpd.

After this patch, since pm_genpd_runtime_suspend() immediately walks the
hierarchy of the ->runtime_suspend() callbacks, fine-grained PM is enabled
throughout all the levels of runtime PM callbacks.

iiii)
Enable fine-grained PM for IRQ safe devices

Per the definition for an IRQ safe device, its runtime PM callbacks must
be able to execute in atomic context. In the path while genpd walks the
hierarchy of the ->runtime_suspend() callbacks for the device, it uses a
mutex. Therefore, genpd prevents that path to be executed for IRQ safe
devices.

As this patch changes pm_genpd_runtime_suspend() to immediately walk the
hierarchy of the ->runtime_suspend() callbacks and without needing to use
a mutex, fine-grained PM is enabled throughout all the levels of runtime
PM callbacks for IRQ safe devices.

Unfortunately this patch also comes with a drawback, as described in the
summary below.

Driver's/subsystem's runtime PM callbacks may be invoked even when the
genpd hasn't actually powered off the PM domain, potentially introducing
unnecessary latency.

However, in most cases, saving/restoring register contexts for devices are
typically fast operations or can be optimized in device specific ways
(e.g. shadow copies of register contents in memory, device-specific checks
to see if context has been lost before restoring context, etc.).

Still, in some cases the driver/subsystem may suffer from latency if
runtime PM is used in a very fine-grained manner (e.g. for each IO request
or xfer). To prevent that extra overhead, the driver/subsystem may deploy
the runtime PM autosuspend feature.
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
Reviewed-by: default avatarKevin Hilman <khilman@linaro.org>
Tested-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Tested-by: default avatarLina Iyer <lina.iyer@linaro.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      ba2bbfbf
  5. 26 Jul, 2015 9 commits
    • Linus Torvalds's avatar
      Linux 4.2-rc4 · cbfe8fa6
      Linus Torvalds authored
      cbfe8fa6
    • Linus Torvalds's avatar
      Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 2579d019
      Linus Torvalds authored 
      Pull perf fix from Thomas Gleixner:
 "A single fix for the intel cqm perf facility to prevent IPIs from
  interrupt context"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel/cqm: Return cached counter value from IRQ context
      2579d019
    • Linus Torvalds's avatar
      Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 28003486
      Linus Torvalds authored 
      Pull x86 fixes from Thomas Gleixner:
 "This update contains:

   - the manual revert of the SYSCALL32 changes which caused a
     regression

   - a fix for the MPX vma handling

   - three fixes for the ioremap 'is ram' checks.

   - PAT warning fixes

   - a trivial fix for the size calculation of TLB tracepoints

   - handle old EFI structures gracefully

  This also contains a PAT fix from Jan plus a revert thereof.  Toshi
  explained why the code is correct"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm/pat: Revert 'Adjust default caching mode translation tables'
  x86/asm/entry/32: Revert 'Do not use R9 in SYSCALL32' commit
  x86/mm: Fix newly introduced printk format warnings
  mm: Fix bugs in region_is_ram()
  x86/mm: Remove region_is_ram() call from ioremap
  x86/mm: Move warning from __ioremap_check_ram() to the call site
  x86/mm/pat, drivers/media/ivtv: Move the PAT warning and replace WARN() with pr_warn()
  x86/mm/pat, drivers/infiniband/ipath: Replace WARN() with pr_warn()
  x86/mm/pat: Adjust default caching mode translation tables
  x86/fpu: Disable dependent CPU features on "noxsave"
  x86/mpx: Do not set ->vm_ops on MPX VMAs
  x86/mm: Add parenthesis for TLB tracepoint size calculation
  efi: Handle memory error structures produced based on old versions of standard
      28003486
    • Thomas Gleixner's avatar
      x86/mm/pat: Revert 'Adjust default caching mode translation tables' · 1a4e8795
      Thomas Gleixner authored 
      Toshi explains:

"No, the default values need to be set to the fallback types,
 i.e. minimal supported mode.  For WC and WT, UC is the fallback type.

 When PAT is disabled, pat_init() does update the tables below to
 enable WT per the default BIOS setup.  However, when PAT is enabled,
 but CPU has PAT -errata, WT falls back to UC per the default values."

Revert: ca1fec58 'x86/mm/pat: Adjust default caching mode translation tables'
Requested-by: default avatarToshi Kani <toshi.kani@hp.com>
Cc: Jan Beulich <jbeulich@suse.de>
Link: http://lkml.kernel.org/r/1437577776.3214.252.camel@hp.comSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      1a4e8795
    • Matt Fleming's avatar
      perf/x86/intel/cqm: Return cached counter value from IRQ context · 2c534c0d
      Matt Fleming authored 
      Peter reported the following potential crash which I was able to
reproduce with his test program,

[  148.765788] ------------[ cut here ]------------
[  148.765796] WARNING: CPU: 34 PID: 2840 at kernel/smp.c:417 smp_call_function_many+0xb6/0x260()
[  148.765797] Modules linked in:
[  148.765800] CPU: 34 PID: 2840 Comm: perf Not tainted 4.2.0-rc1+ #4
[  148.765803]  ffffffff81cdc398 ffff88085f105950 ffffffff818bdfd5 0000000000000007
[  148.765805]  0000000000000000 ffff88085f105990 ffffffff810e413a 0000000000000000
[  148.765807]  ffffffff82301080 0000000000000022 ffffffff8107f640 ffffffff8107f640
[  148.765809] Call Trace:
[  148.765810]  <NMI>  [<ffffffff818bdfd5>] dump_stack+0x45/0x57
[  148.765818]  [<ffffffff810e413a>] warn_slowpath_common+0x8a/0xc0
[  148.765822]  [<ffffffff8107f640>] ? intel_cqm_stable+0x60/0x60
[  148.765824]  [<ffffffff8107f640>] ? intel_cqm_stable+0x60/0x60
[  148.765825]  [<ffffffff810e422a>] warn_slowpath_null+0x1a/0x20
[  148.765827]  [<ffffffff811613f6>] smp_call_function_many+0xb6/0x260
[  148.765829]  [<ffffffff8107f640>] ? intel_cqm_stable+0x60/0x60
[  148.765831]  [<ffffffff81161748>] on_each_cpu_mask+0x28/0x60
[  148.765832]  [<ffffffff8107f6ef>] intel_cqm_event_count+0x7f/0xe0
[  148.765836]  [<ffffffff811cdd35>] perf_output_read+0x2a5/0x400
[  148.765839]  [<ffffffff811d2e5a>] perf_output_sample+0x31a/0x590
[  148.765840]  [<ffffffff811d333d>] ? perf_prepare_sample+0x26d/0x380
[  148.765841]  [<ffffffff811d3497>] perf_event_output+0x47/0x60
[  148.765843]  [<ffffffff811d36c5>] __perf_event_overflow+0x215/0x240
[  148.765844]  [<ffffffff811d4124>] perf_event_overflow+0x14/0x20
[  148.765847]  [<ffffffff8107e7f4>] intel_pmu_handle_irq+0x1d4/0x440
[  148.765849]  [<ffffffff811d07a6>] ? __perf_event_task_sched_in+0x36/0xa0
[  148.765853]  [<ffffffff81219bad>] ? vunmap_page_range+0x19d/0x2f0
[  148.765854]  [<ffffffff81219d11>] ? unmap_kernel_range_noflush+0x11/0x20
[  148.765859]  [<ffffffff814ce6fe>] ? ghes_copy_tofrom_phys+0x11e/0x2a0
[  148.765863]  [<ffffffff8109e5db>] ? native_apic_msr_write+0x2b/0x30
[  148.765865]  [<ffffffff8109e44d>] ? x2apic_send_IPI_self+0x1d/0x20
[  148.765869]  [<ffffffff81065135>] ? arch_irq_work_raise+0x35/0x40
[  148.765872]  [<ffffffff811c8d86>] ? irq_work_queue+0x66/0x80
[  148.765875]  [<ffffffff81075306>] perf_event_nmi_handler+0x26/0x40
[  148.765877]  [<ffffffff81063ed9>] nmi_handle+0x79/0x100
[  148.765879]  [<ffffffff81064422>] default_do_nmi+0x42/0x100
[  148.765880]  [<ffffffff81064563>] do_nmi+0x83/0xb0
[  148.765884]  [<ffffffff818c7c0f>] end_repeat_nmi+0x1e/0x2e
[  148.765886]  [<ffffffff811d07a6>] ? __perf_event_task_sched_in+0x36/0xa0
[  148.765888]  [<ffffffff811d07a6>] ? __perf_event_task_sched_in+0x36/0xa0
[  148.765890]  [<ffffffff811d07a6>] ? __perf_event_task_sched_in+0x36/0xa0
[  148.765891]  <<EOE>>  [<ffffffff8110ab66>] finish_task_switch+0x156/0x210
[  148.765898]  [<ffffffff818c1671>] __schedule+0x341/0x920
[  148.765899]  [<ffffffff818c1c87>] schedule+0x37/0x80
[  148.765903]  [<ffffffff810ae1af>] ? do_page_fault+0x2f/0x80
[  148.765905]  [<ffffffff818c1f4a>] schedule_user+0x1a/0x50
[  148.765907]  [<ffffffff818c666c>] retint_careful+0x14/0x32
[  148.765908] ---[ end trace e33ff2be78e14901 ]---

The CQM task events are not safe to be called from within interrupt
context because they require performing an IPI to read the counter value
on all sockets. And performing IPIs from within IRQ context is a
"no-no".

Make do with the last read counter value currently event in
event->count when we're invoked in this context.
Reported-by: default avatarPeter Zijlstra <peterz@infradead.org>
Signed-off-by: default avatarMatt Fleming <matt.fleming@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vikas Shivappa <vikas.shivappa@intel.com>
Cc: Kanaka Juvva <kanaka.d.juvva@intel.com>
Cc: Will Auld <will.auld@intel.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/1437490509-15373-1-git-send-email-matt@codeblueprint.co.ukSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      2c534c0d
    • Linus Torvalds's avatar
      Merge tag 'usb-4.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb · 26ae19a3
      Linus Torvalds authored 
      Pull USB fixes from Greg KH:
 "Here's a few USB and PHY fixes for 4.2-rc4.

  Nothing major, the shortlog has the full details.

  All of these have been in linux-next successfully"

* tag 'usb-4.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (21 commits)
  USB: OHCI: fix bad #define in ohci-tmio.c
  cdc-acm: Destroy acm_minors IDR on module exit
  usb-storage: Add ignore-device quirk for gm12u320 based usb mini projectors
  usb-storage: ignore ZTE MF 823 card reader in mode 0x1225
  USB: OHCI: Fix race between ED unlink and URB submission
  usb: core: lpm: set lpm_capable for root hub device
  xhci: do not report PLC when link is in internal resume state
  xhci: prevent bus_suspend if SS port resuming in phase 1
  xhci: report U3 when link is in resume state
  xhci: Calculate old endpoints correctly on device reset
  usb: xhci: Bugfix for NULL pointer deference in xhci_endpoint_init() function
  xhci: Workaround to get D3 working in Intel xHCI
  xhci: call BIOS workaround to enable runtime suspend on Intel Braswell
  usb: dwc3: Reset the transfer resource index on SET_INTERFACE
  usb: gadget: udc: core: Fix argument of dma_map_single for IOMMU
  usb: gadget: mv_udc_core: fix phy_regs I/O memory leak
  usb: ulpi: ulpi_init should be executed in subsys_initcall
  phy: berlin-usb: fix divider for BG2
  phy: berlin-usb: fix divider for BG2CD
  phy/pxa: add HAS_IOMEM dependency
  ...
      26ae19a3
    • Linus Torvalds's avatar
      Merge tag 'tty-4.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty · 82b35f37
      Linus Torvalds authored 
      Pull tty/serial driver fixes from Greg KH:
 "Here are a number of small serial and tty fixes for reported issues.

  All have been in linux-next successfully"

* tag 'tty-4.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  tty: vt: Fix !TASK_RUNNING diagnostic warning from paste_selection()
  serial: core: Fix crashes while echoing when closing
  m32r: Add ioreadXX/iowriteXX big-endian mmio accessors
  Revert "serial: imx: initialized DMA w/o HW flow enabled"
  sc16is7xx: fix FIFO address of secondary UART
  sc16is7xx: fix Kconfig dependencies
  serial: etraxfs-uart: Fix release etraxfs_uart_ports
  tty/vt: Fix the memory leak in visual_init
  serial: amba-pl011: Fix devm_ioremap_resource return value check
  n_tty: signal and flush atomically
      82b35f37
    • Linus Torvalds's avatar
      Merge tag 'staging-4.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging · b0de415a
      Linus Torvalds authored 
      Pull staging driver fixes from Greg KH:
 "Here are a number of iio and staging driver fixes for reported issues
  for 4.2-rc4.

  All have been in linux-next for a while with no problems"

* tag 'staging-4.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (34 commits)
  iio:light:stk3310: make endianness independent of host
  iio:light:stk3310: move device register to end of probe
  iio: mma8452: use iio event type IIO_EV_TYPE_MAG
  iio: mcp320x: Fix NULL pointer dereference
  iio: adc: vf610: fix the adc register read fail issue
  iio: mlx96014: Replace offset sign
  iio: magnetometer: mmc35240: fix SET/RESET sequence
  iio: magnetometer: mmc35240: Fix SET/RESET mask
  iio: magnetometer: mmc35240: Fix crash in pm suspend
  iio:magnetometer:bmc150_magn: output intended variable
  iio:magnetometer:bmc150_magn: add regmap dependency
  staging: vt6656: check ieee80211_bss_conf bssid not NULL
  staging: vt6655: check ieee80211_bss_conf bssid not NULL
  iio: tmp006: Check channel info on write
  iio: sx9500: Add missing init in sx9500_buffer_pre{en,dis}able()
  iio:light:ltr501: fix regmap dependency
  iio:light:ltr501: fix variable in ltr501_init
  iio: sx9500: fix bug in compensation code
  iio: sx9500: rework error handling of raw readings
  iio: magnetometer: mmc35240: fix available sampling frequencies
  ...
      b0de415a
    • Linus Torvalds's avatar
      Merge tag 'char-misc-4.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc · e433b656
      Linus Torvalds authored 
      Pull char/misc driver fixes from Greg KH:
 "Here are some char and misc driver fixes for reported issues.

  One parport patch is reverted as it was incorrect, thanks to testing
  by the 0-day bot"

* tag 'char-misc-4.2-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  parport: Revert "parport: fix memory leak"
  mei: prevent unloading mei hw modules while the device is opened.
  misc: mic: scif bug fix for vmalloc_to_page crash
  parport: fix freeing freed memory
  parport: fix memory leak
  parport: fix error handling
      e433b656
  7. 25 Jul, 2015 7 commits
  9. 24 Jul, 2015 20 commits
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