1. 20 10月, 2011 1 次提交
  2. 13 10月, 2011 3 次提交
    • R
      pinctrl: add a driver for the CSR SiRFprimaII pinmux · 393daa81
      Rongjun Ying 提交于
      This creates a pin controller driver for the SiRFprinaII
      pin mux portions.
      Signed-off-by: NRongjun Ying <Rongjun.Ying@csr.com>
      Signed-off-by: NBarry Song <Baohua.Song@csr.com>
      [Fixup for changed function names and semantics in the v10 patch]
      Signed-off-by: NLinus Walleij <linus.walleij@stericsson.com>
      393daa81
    • L
      pinctrl: add a driver for the U300 pinmux · 98da3529
      Linus Walleij 提交于
      This adds a driver for the U300 pinmux portions of the system
      controller "SYSCON". It also serves as an example of how to use
      the pinmux subsystem. This driver also houses the platform data
      for the only supported platform.
      
      This deletes the old U300 driver in arch/arm/mach-u300 and
      replace it with a driver using the new subsystem.
      
      The new driver is considerably fatter than the old one, but it
      also registers all 467 pins of the system and adds the power
      and EMIF pin groups and corresponding functions. The idea
      is to use this driver as a a reference for other
      implementation so it needs to be as complete and verbose
      as possible.
      Reviewed-by: NBarry Song <21cnbao@gmail.com>
      [Fixup for changed function names and semantics in the v10 patch]
      Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
      98da3529
    • L
      drivers: create a pin control subsystem · 2744e8af
      Linus Walleij 提交于
      This creates a subsystem for handling of pin control devices.
      These are devices that control different aspects of package
      pins.
      
      Currently it handles pinmuxing, i.e. assigning electronic
      functions to groups of pins on primarily PGA and BGA type of
      chip packages which are common in embedded systems.
      
      The plan is to also handle other I/O pin control aspects
      such as biasing, driving, input properties such as
      schmitt-triggering, load capacitance etc within this
      subsystem, to remove a lot of ARM arch code as well as
      feature-creepy GPIO drivers which are implementing the same
      thing over and over again.
      
      This is being done to depopulate the arch/arm/* directory
      of such custom drivers and try to abstract the infrastructure
      they all need. See the Documentation/pinctrl.txt file that is
      part of this patch for more details.
      
      ChangeLog v1->v2:
      
      - Various minor fixes from Joe's and Stephens review comments
      - Added a pinmux_config() that can invoke custom configuration
        with arbitrary data passed in or out to/from the pinmux driver
      
      ChangeLog v2->v3:
      
      - Renamed subsystem folder to "pinctrl" since we will likely
        want to keep other pin control such as biasing in this
        subsystem too, so let us keep to something generic even though
        we're mainly doing pinmux now.
      - As a consequence, register pins as an abstract entity separate
        from the pinmux. The muxing functions will claim pins out of the
        pin pool and make sure they do not collide. Pins can now be
        named by the pinctrl core.
      - Converted the pin lookup from a static array into a radix tree,
        I agreed with Grant Likely to try to avoid any static allocation
        (which is crap for device tree stuff) so I just rewrote this
        to be dynamic, just like irq number descriptors. The
        platform-wide definition of number of pins goes away - this is
        now just the sum total of the pins registered to the subsystem.
      - Make sure mappings with only a function name and no device
        works properly.
      
      ChangeLog v3->v4:
      
      - Define a number space per controller instead of globally,
        Stephen and Grant requested the same thing so now maps need to
        define target controller, and the radix tree of pin descriptors
        is a property on each pin controller device.
      - Add a compulsory pinctrl device entry to the pinctrl mapping
        table. This must match the pinctrl device, like "pinctrl.0"
      - Split the file core.c in two: core.c and pinmux.c where the
        latter carry all pinmux stuff, the core is for generic pin
        control, and use local headers to access functionality between
        files. It is now possible to implement a "blank" pin controller
        without pinmux capabilities. This split will make new additions
        like pindrive.c, pinbias.c etc possible for combined drivers
        and chunks of functionality which is a GoodThing(TM).
      - Rewrite the interaction with the GPIO subsystem - the pin
        controller descriptor now handles this by defining an offset
        into the GPIO numberspace for its handled pin range. This is
        used to look up the apropriate pin controller for a GPIO pin.
        Then that specific GPIO range is matched 1-1 for the target
        controller instance.
      - Fixed a number of review comments from Joe Perches.
      - Broke out a header file pinctrl.h for the core pin handling
        stuff that will be reused by other stuff than pinmux.
      - Fixed some erroneous EXPORT() stuff.
      - Remove mispatched U300 Kconfig and Makefile entries
      - Fixed a number of review comments from Stephen Warren, not all
        of them - still WIP. But I think the new mapping that will
        specify which function goes to which pin mux controller address
        50% of your concerns (else beat me up).
      
      ChangeLog v4->v5:
      
      - Defined a "position" for each function, so the pin controller now
        tracks a function in a certain position, and the pinmux maps define
        what position you want the function in. (Feedback from Stephen
        Warren and Sascha Hauer).
      - Since we now need to request a combined function+position from
        the machine mapping table that connect mux settings to drivers,
        it was extended with a position field and a name field. The
        name field is now used if you e.g. need to switch between two
        mux map settings at runtime.
      - Switched from a class device to using struct bus_type for this
        subsystem. Verified sysfs functionality: seems to work fine.
        (Feedback from Arnd Bergmann and Greg Kroah-Hartman)
      - Define a per pincontroller list of GPIO ranges from the GPIO
        pin space that can be handled by the pin controller. These can
        be added one by one at runtime. (Feedback from Barry Song)
      - Expanded documentation of regulator_[get|enable|disable|put]
        semantics.
      - Fixed a number of review comments from Barry Song. (Thanks!)
      
      ChangeLog v5->v6:
      
      - Create an abstract pin group concept that can sort pins into
        named and enumerated groups no matter what the use of these
        groups may be, one possible usecase is a group of pins being
        muxed in or so. The intention is however to also use these
        groups for other pin control activities.
      - Make it compulsory for pinmux functions to associate with
        at least one group, so the abstract pin group concept is used
        to define the groups of pins affected by a pinmux function.
        The pinmux driver interface has been altered so as to enforce
        a function to list applicable groups per function.
      - Provide an optional .group entry in the pinmux machine map
        so the map can select beteween different available groups
        to be used with a certain function.
      - Consequent changes all over the place so that e.g. debugfs
        present reasonable information about the world.
      - Drop the per-pin mux (*config) function in the pinmux_ops
        struct - I was afraid that this would start to be used for
        things totally unrelated to muxing, we can introduce that to
        the generic struct pinctrl_ops if needed. I want to keep
        muxing orthogonal to other pin control subjects and not mix
        these things up.
      
      ChangeLog v6->v7:
      
      - Make it possible to have several map entries matching the
        same device, pin controller and function, but using
        a different group, and alter the semantics so that
        pinmux_get() will pick all matching map entries, and
        store the associated groups in a list. The list will
        then be iterated over at pinmux_enable()/pinmux_disable()
        and corresponding driver functions called for each
        defined group. Notice that you're only allowed to map
        multiple *groups* to the same
        { device, pin controller, function } triplet, attempts
        to map the same device to multiple pin controllers will
        for example fail. This is hopefully the crucial feature
        requested by Stephen Warren.
      - Add a pinmux hogging field to the pinmux mapping entries,
        and enable the pinmux core to hog pinmux map entries.
        This currently only works for pinmuxes without assigned
        devices as it looks now, but with device trees we can
        look up the corresponding struct device * entries when
        we register the pinmux driver, and have it hog each
        pinmux map in turn, for a simple approach to
        non-dynamic pin muxing. This addresses an issue from
        Grant Likely that the machine should take care of as
        much of the pinmux setup as possible, not the devices.
        By supplying a list of hogs, it can now instruct the
        core to take care of any static mappings.
      - Switch pinmux group retrieveal function to grab an
        array of strings representing the groups rather than an
        array of unsigned and rewrite accordingly.
      - Alter debugfs to show the grouplist handled by each
        pinmux. Also add a list of hogs.
      - Dynamically allocate a struct pinmux at pinmux_get() and
        free it at pinmux_put(), then add these to the global
        list of pinmuxes active as we go along.
      - Go over the list of pinmux maps at pinmux_get() time
        and repeatedly apply matches.
      - Retrieve applicable groups per function from the driver
        as a string array rather than a unsigned array, then
        lookup the enumerators.
      - Make the device to pinmux map a singleton - only allow the
        mapping table to be registered once and even tag the
        registration function with __init so it surely won't be
        abused.
      - Create a separate debugfs file to view the pinmux map at
        runtime.
      - Introduce a spin lock to the pin descriptor struct, lock it
        when modifying pin status entries. Reported by Stijn Devriendt.
      - Fix up the documentation after review from Stephen Warren.
      - Let the GPIO ranges give names as const char * instead of some
        fixed-length string.
      - add a function to unregister GPIO ranges to mirror the
        registration function.
      - Privatized the struct pinctrl_device and removed it from the
        <linux/pinctrl/pinctrl.h> API, the drivers do not need to know
        the members of this struct. It is now in the local header
        "core.h".
      - Rename the concept of "anonymous" mux maps to "system" muxes
        and add convenience macros and documentation.
      
      ChangeLog v7->v8:
      
      - Delete the leftover pinmux_config() function from the
       <linux/pinctrl/pinmux.h> header.
      - Fix a race condition found by Stijn Devriendt in pin_request()
      
      ChangeLog v8->v9:
      
      - Drop the bus_type and the sysfs attributes and all, we're not on
        the clear about how this should be used for e.g. userspace
        interfaces so let us save this for the future.
      - Use the right name in MAINTAINERS, PIN CONTROL rather than
        PINMUX
      - Don't kfree() the device state holder, let the .remove() callback
        handle this.
      - Fix up numerous kerneldoc headers to have one line for the function
        description and more verbose documentation below the parameters
      
      ChangeLog v9->v10:
      - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch
        from Steven Rothwell
      - fix pinctrl_register error handling, folded in a patch from
        Axel Lin
      - Various fixes to documentation text so that it's consistent.
      - Removed pointless comment from drivers/Kconfig
      - Removed dependency on SYSFS since we removed the bus in
        v9.
      - Renamed hopelessly abbreviated pctldev_* functions to the
        more verbose pinctrl_dev_*
      - Drop mutex properly when looking up GPIO ranges
      - Return NULL instead of ERR_PTR() errors on registration of
        pin controllers, using cast pointers is fragile. We can
        live without the detailed error codes for sure.
      
      Cc: Stijn Devriendt <highguy@gmail.com>
      Cc: Joe Perches <joe@perches.com>
      Cc: Russell King <linux@arm.linux.org.uk>
      Acked-by: NGrant Likely <grant.likely@secretlab.ca>
      Acked-by: NStephen Warren <swarren@nvidia.com>
      Tested-by: NBarry Song <21cnbao@gmail.com>
      Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
      2744e8af
  3. 27 9月, 2011 1 次提交
    • R
      PM / Clocks: Do not acquire a mutex under a spinlock · e8b364b8
      Rafael J. Wysocki 提交于
      Commit b7ab83ed (PM: Use spinlock instead of mutex in clock
      management functions) introduced a regression causing clocks_mutex
      to be acquired under a spinlock.  This happens because
      pm_clk_suspend() and pm_clk_resume() call pm_clk_acquire() under
      pcd->lock, but pm_clk_acquire() executes clk_get() which causes
      clocks_mutex to be acquired.  Similarly, __pm_clk_remove(),
      executed under pcd->lock, calls clk_put(), which also causes
      clocks_mutex to be acquired.
      
      To fix those problems make pm_clk_add() call pm_clk_acquire(), so
      that pm_clk_suspend() and pm_clk_resume() don't have to do that.
      Change pm_clk_remove() and pm_clk_destroy() to separate
      modifications of the pcd->clock_list list from the actual removal of
      PM clock entry objects done by __pm_clk_remove().
      Reported-and-tested-by: NGuennadi Liakhovetski <g.liakhovetski@gmx.de>
      Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
      Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      e8b364b8
  4. 24 9月, 2011 6 次提交
  5. 23 9月, 2011 7 次提交
    • A
      drm/radeon/kms: fix DDIA enable on some rs690 systems · fdfc6159
      Alex Deucher 提交于
      DVOOutputControl checks the value of of bios scratch reg 3
      on some tables and assumes the encoder is already enabled
      if the DFP2_ACTIVE bit is set.  Clear that bit so the table
      sets the DDIA enable bit properly.
      Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
      Cc: stable@kernel.org
      Signed-off-by: NDave Airlie <airlied@redhat.com>
      fdfc6159
    • D
      Revert "drm/radeon/kms: fix typo in r100_blit_copy" · d9ad77eb
      Dave Airlie 提交于
      This reverts commit 18b4fada.
      
      This code was correct, apologies to anyone who noticed things broke.
      
      revert contents are different due to another commit in between.
      Signed-off-by: NDave Airlie <airlied@redhat.com>
      d9ad77eb
    • P
      TPM: Zero buffer after copying to userspace · 3321c07a
      Peter Huewe 提交于
      Since the buffer might contain security related data it might be a good idea to
      zero the buffer after we have copied it to userspace.
      
      This got assigned CVE-2011-1162.
      Signed-off-by: NRajiv Andrade <srajiv@linux.vnet.ibm.com>
      Cc: Stable Kernel <stable@kernel.org>
      Signed-off-by: NJames Morris <jmorris@namei.org>
      3321c07a
    • P
      TPM: Call tpm_transmit with correct size · 6b07d30a
      Peter Huewe 提交于
      This patch changes the call of tpm_transmit by supplying the size of the
      userspace buffer instead of TPM_BUFSIZE.
      
      This got assigned CVE-2011-1161.
      
      [The first hunk didn't make sense given one could expect
       way less data than TPM_BUFSIZE, so added tpm_transmit boundary
       check over bufsiz instead
       The last parameter of tpm_transmit() reflects the amount
       of data expected from the device, and not the buffer size
       being supplied to it. It isn't ideal to parse it directly,
       so we just set it to the maximum the input buffer can handle
       and let the userspace API to do such job.]
      Signed-off-by: NRajiv Andrade <srajiv@linux.vnet.ibm.com>
      Cc: Stable Kernel <stable@kernel.org>
      Signed-off-by: NJames Morris <jmorris@namei.org>
      6b07d30a
    • A
      TPM: tpm_nsc: Fix a double free of pdev in cleanup_nsc · de69113e
      Axel Lin 提交于
      platform_device_unregister() will release all resources
      and remove it from the subsystem, then drop reference count by
      calling platform_device_put().
      
      We should not call kfree(pdev) after platform_device_unregister(pdev).
      Signed-off-by: NAxel Lin <axel.lin@gmail.com>
      Signed-off-by: NRajiv Andrade <srajiv@linux.vnet.ibm.com>
      Signed-off-by: NJames Morris <jmorris@namei.org>
      de69113e
    • G
      TPM: TCG_ATMEL should depend on HAS_IOPORT · 5ce5ed35
      Geert Uytterhoeven 提交于
      On m68k, I get:
      
      drivers/char/tpm/tpm_atmel.h: In function ‘atmel_get_base_addr’:
      drivers/char/tpm/tpm_atmel.h:129: error: implicit declaration of function ‘ioport_map’
      drivers/char/tpm/tpm_atmel.h:129: warning: return makes pointer from integer without a cast
      
      The code in tpm_atmel.h supports PPC64 (using the device tree and ioremap())
      and "anything else" (using ioport_map()). However, ioportmap() is only
      available on platforms that set HAS_IOPORT.
      
      Although PC64 seems to have HAS_IOPORT, a "depends on HAS_IOPORT" should work,
      but I think it's better to expose the special PPC64 handling explicit using
      "depends on PPC64 || HAS_IOPORT".
      Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
      Signed-off-by: NRajiv Andrade <srajiv@linux.vnet.ibm.com>
      Signed-off-by: NJames Morris <jmorris@namei.org>
      5ce5ed35
    • G
      zorro: Defer device_register() until all devices have been identified · a7f4d00a
      Geert Uytterhoeven 提交于
      As the Amiga Zorro II address space is limited to 8.5 MiB and Zorro
      devices can contain only one BAR, several Amiga Zorro II expansion
      boards (mainly graphics cards) contain multiple Zorro devices: a small
      one for the control registers and one (or more) for the graphics memory.
      
      The conversion of cirrusfb to the new driver framework introduced a
      regression: the driver contains a zorro_driver for the first Zorro
      device, and uses the (old) zorro_find_device() call to find the second
      Zorro device.
      
      However, as the Zorro core calls device_register() as soon as a Zorro
      device is identified, it may not have identified the second Zorro device
      belonging to the same physical Zorro expansion card.  Hence cirrusfb
      could no longer find the second part of the Picasso II graphics card,
      causing a NULL pointer dereference.
      
      Defer the registration of Zorro devices with the driver framework until
      all Zorro devices have been identified to fix this.
      
      Note that the alternative solution (modifying cirrusfb to register a
      zorro_driver for all Zorro devices belonging to a graphics card, instead
      of only for the first one, and adding a synchronization mechanism to
      defer initialization until all have been found), is not an option, as on
      some cards one device may be optional (e.g.  the second bank of 2 MiB of
      graphics memory on the Picasso IV in Zorro II mode).
      Reported-by: NIngo Jürgensmann <ij@2011.bluespice.org>
      Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
      Cc: stable@kernel.org
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      a7f4d00a
  6. 22 9月, 2011 5 次提交
  7. 21 9月, 2011 10 次提交
  8. 20 9月, 2011 7 次提交
    • A
      watchdog: Initconst section fixes for watchdog · 4e8858d5
      Andi Kleen 提交于
      Signed-off-by: NAndi Kleen <ak@linux.intel.com>
      Signed-off-by: NWim Van Sebroeck <wim@iguana.be>
      4e8858d5
    • J
      watchdog: lantiq: fix watchdogs timeout handling · 9cfce47b
      John Crispin 提交于
      The enable function was using the global timeout variable for local operations.
      This resulted in the value of the global variable being corrupted, thus
      breaking the code.
      Signed-off-by: NJohn Crispin <blogic@openwrt.org>
      Signed-off-by: NThomas Langer <thomas.langer@lantiq.com>
      Signed-off-by: NWim Van Sebroeck <wim@iguana.be>
      Cc: linux-watchdog@vger.kernel.org
      Cc: linux-mips@linux-mips.org
      9cfce47b
    • N
      watchdog: hpwdt: prevent multiple "NMI occurred" messages · dbc018ec
      Naga Chumbalkar 提交于
      On platforms with no iCRU support don't print two, (possibly conflicting),
      "NMI occurred" messages when the firmware is unable to source the NMI.
      
      Please note that one of the enhancements to the v1.3.0 hpwdt driver is to panic and allow
      KDUMP to succeed even on NMIs that are unknown to the platform firmware.
      Signed-off-by: NNaga Chumbalkar <nagananda.chumbalkar@hp.com>
      Reviewed-by: NThomas Mingarelli <thomas.mingarelli@hp.com>
      Signed-off-by: NWim Van Sebroeck <wim@iguana.be>
      dbc018ec
    • H
      watchdog: WatchDog Timer Driver Core - use passed watchdog_device · cb7efc02
      H Hartley Sweeten 提交于
      Use the passed watchdog_device instead of the static global variable when
      testing and setting the status in watchdog_ping, watchdog_start, and
      watchdog_stop.  Note that the callers of these functions are actually
      passing the static global variable.
      Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
      Signed-off-by: NWim Van Sebroeck <wim@iguana.be>
      cb7efc02
    • A
      USB: xHCI: prevent infinite loop when processing MSE event · c2d7b49f
      Andiry Xu 提交于
      When a xHC host is unable to handle isochronous transfer in the
      interval, it reports a Missed Service Error event and skips some tds.
      
      Currently xhci driver handles MSE event in the following ways:
      
      1. When encounter a MSE event, set ep->skip flag, update event ring
         dequeue pointer and return.
      
      2. When encounter the next event on this ep, the driver will run the
         do-while loop, fetch td from ep's td_list to find the td
         corresponding to this event.  All tds missed are marked as short
         transfer(-EXDEV).
      
      The do-while loop will end in two ways:
      
      1. If the td pointed by the event trb is found;
      
      2. If the ep ring's td_list is empty.
      
      However, if a buggy HW reports some unpredicted event (for example, an
      overrun event following a MSE event while the ep ring is actually not
      empty), the driver will never find the td, and it will loop until the
      td_list is empty.
      
      Unfortunately, the spinlock is dropped when give back a urb in the
      do-while loop.  During the spinlock released period, the class driver
      may still submit urbs and add tds to the td_list.  This may cause
      disaster, since the td_list will never be empty and the loop never ends,
      and the system hangs.
      
      To fix this, count the number of TDs on the ep ring before skipping TDs,
      and quit the loop when skipped that number of tds.  This guarantees the
      do-while loop will end after certain number of cycles, and driver will
      not be trapped in an infinite loop.
      Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
      Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      c2d7b49f
    • G
      USB: xhci: Set change bit when warm reset change is set. · 44f4c3ed
      Greg KH 提交于
      Sometimes, when a USB 3.0 device is disconnected, the Intel Panther
      Point xHCI host controller will report a link state change with the
      state set to "SS.Inactive".  This causes the xHCI host controller to
      issue a warm port reset, which doesn't finish before the USB core times
      out while waiting for it to complete.
      
      When the warm port reset does complete, and the xHC gives back a port
      status change event, the xHCI driver kicks khubd.  However, it fails to
      set the bit indicating there is a change event for that port because the
      logic in xhci-hub.c doesn't check for the warm port reset bit.
      
      After that, the warm port status change bit is never cleared by the USB
      core, and the xHC stops reporting port status change bits.  (The xHCI
      spec says it shouldn't report more port events until all change bits are
      cleared.) This means any port changes when a new device is connected
      will never be reported, and the port will seem "dead" until the xHCI
      driver is unloaded and reloaded, or the computer is rebooted.  Fix this
      by making the xHCI driver set the port change bit when a warm port reset
      change bit is set.
      
      A better solution would be to make the USB core handle warm port reset
      in differently, merging the current code with the standard port reset
      code that does an incremental backoff on the timeout, and tries to
      complete the port reset two more times before giving up.  That more
      complicated fix will be merged next window, and this fix will be
      backported to stable.
      
      This should be backported to kernels as old as 3.0, since that was the
      first kernel with commit a11496eb ("xHCI: warm reset support").
      Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
      Cc: stable@kernel.org
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      44f4c3ed
    • R
      staging: fix comedi build when ISA_DMA_API is enabled but COMEDI_PCI is not enabled · c19cc78e
      Randy Dunlap 提交于
      Fix build when CONFIG_ISA_DMA_API is enabled but
      CONFIG_COMEDI_PCI[_DRIVERS] is not enabled.
      
      Fixes these build errors:
      
        drivers/staging/comedi/drivers/ni_labpc.c: In function 'labpc_ai_cmd':
        drivers/staging/comedi/drivers/ni_labpc.c:1351: error: implicit declaration of function 'labpc_suggest_transfer_size'
        drivers/staging/comedi/drivers/ni_labpc.c: At top level:
        drivers/staging/comedi/drivers/ni_labpc.c:1802: error: conflicting types for 'labpc_suggest_transfer_size'
        drivers/staging/comedi/drivers/ni_labpc.c:1351: note: previous implicit declaration of 'labpc_suggest_transfer_size' was here
      Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      c19cc78e