1. 08 Jan, 2013 15 commits
  2. 07 Jan, 2013 8 commits
    • Viresh Kumar's avatar
      dmaengine: dw_dmac: Update documentation style comments for dw_dma_platform_data · 177d2bf5
      Viresh Kumar authored
      Documentation style comments were missing for few fields in struct
      dw_dma_platform_data. Add these.
      Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
      Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
      Signed-off-by: default avatarVinod Koul <vinod.koul@linux.intel.com>
      177d2bf5
    • Wei Yongjun's avatar
      pch_dma: use module_pci_driver to simplify the code · 53b9989b
      Wei Yongjun authored
      Use the module_pci_driver() macro to make the code simpler
      by eliminating module_init and module_exit calls.
      
      dpatch engine is used to auto generate this patch.
      (https://github.com/weiyj/dpatch)
      Signed-off-by: default avatarWei Yongjun <yongjun_wei@trendmicro.com.cn>
      Signed-off-by: default avatarVinod Koul <vinod.koul@linux.intel.com>
      53b9989b
    • Kees Cook's avatar
      drivers/dma: remove CONFIG_EXPERIMENTAL · c6a0aec9
      Kees Cook authored
      This config item has not carried much meaning for a while now and is
      almost always enabled by default. As agreed during the Linux kernel
      summit, remove it.
      
      CC: Vinod Koul <vinod.koul@intel.com>
      CC: Dan Williams <djbw@fb.com>
      Signed-off-by: default avatarKees Cook <keescook@chromium.org>
      Signed-off-by: default avatarVinod Koul <vinod.koul@linux.intel.com>
      c6a0aec9
    • Vinod Koul's avatar
    • Matt Porter's avatar
      of: dma: fix typos in generic dma binding definition · deef1244
      Matt Porter authored
      Some semicolons were left out in the examples.
      
      The #dma-channels and #dma-requests properties have a prefix
      that is, by convention, reserved for cell size properties.
      Rename those properties to dma-channels and dma-requests.
      Signed-off-by: default avatarMatt Porter <mporter@ti.com>
      Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
      Acked-by: default avatarJon Hunter <jon-hunter@ti.com>
      Signed-off-by: default avatarVinod Koul <vinod.koul@linux.intel.com>
      deef1244
    • Vinod Koul's avatar
      4c26bc60
    • Jon Hunter's avatar
      of: Add generic device tree DMA helpers · aa3da644
      Jon Hunter authored
      This is based upon the work by Benoit Cousson [1] and Nicolas Ferre [2]
      to add some basic helpers to retrieve a DMA controller device_node and the
      DMA request/channel information.
      
      Aim of DMA helpers
      - The purpose of device-tree is to describe the capabilites of the hardware.
        Thinking about DMA controllers purely from the context of the hardware to
        begin with, we can describe a device in terms of a DMA controller as
        follows ...
        	1. Number of DMA controllers
      	2. Number of channels (maybe physical or logical)
      	3. Mapping of DMA requests signals to DMA controller
      	4. Number of DMA interrupts
      	5. Mapping of DMA interrupts to channels
      - With the above in mind the aim of the DT DMA helper functions is to extract
        the above information from the DT and provide to the appropriate driver.
        However, due to the vast number of DMA controllers and not all are using a
        common driver (such as DMA Engine) it has been seen that this is not a
        trivial task. In previous discussions on this topic the following concerns
        have been raised ...
      	1. How does the binding support devices with multiple DMA controllers?
        	2. How to support both legacy DMA controllers not using DMA Engine as
      	   well as those that support DMA Engine.
      	3. When using with DMA Engine how do we support the various
      	   implementations where the opaque filter function parameter differs
      	   between implementations?
      	4. How do we handle DMA channels that are identified with a string
      	   versus a integer?
      - Hence the design of the DMA helpers has to accomodate the above or align on
        an agreement what can be or should be supported.
      
      Design of DMA helpers
      
      1. Registering DMA controllers
      
         In the case of DMA controllers that are using DMA Engine, requesting a
         channel is performed by calling the following function.
      
      	struct dma_chan *dma_request_channel(dma_cap_mask_t mask,
      			dma_filter_fn filter_fn,
      			void *filter_param);
      
         The mask variable is used to match a type of the device controller in a list
         of controllers. The filter_fn and filter_param are used to identify the
         required dma channel and return a handle to the dma channel of type dma_chan.
      
         From the examples I have seen, the mask and filter_fn are constant
         for a given DMA controller and therefore, we can specify these as controller
         specific data when registering the DMA controller with the device-tree DMA
         helpers.
      
         The filter_param variable is of an unknown type and is typically specific
         to the DMA engine implementation for a given DMA controller. To allow some
         flexibility in the type and formating of this filter_param we employ an
         xlate to translate the device-tree binding information into the appropriate
         format. The xlate function used for a DMA controller can also be specified
         when registering the DMA controller with the device-tree DMA helpers.
      
         Based upon the above, a function for registering the DMA controller with the
         DMA helpers now looks like the below. The data variable is used to pass a
         pointer to DMA controller specific data used by the xlate function.
      
      	int of_dma_controller_register(struct device_node *np,
      		struct dma_chan *(*of_dma_xlate)
      		(struct of_phandle_args *, struct of_dma *),
      		void *data)
      
         For example, in the case where DMA engine is used, we define the following
         structure (that stores the DMA engine capability mask and filter function)
         and pass this to the data variable in the above function.
      
      	struct of_dma_filter_info {
      		dma_cap_mask_t  dma_cap;
      		dma_filter_fn   filter_fn;
      	};
      
      2. Representing and requesting channel information
      
         Please see the dma binding documentation included in this patch for a
         description of how DMA controllers and client information should be
         represented with device-tree. For more information on how this binding
         came about please see [3]. In addition to this, feedback received from
         the Linux kernel summit showed a consensus (among those who attended) to
         use a name to identify DMA client information [4].
      
         A DMA channel can be requested by calling the following function, where name
         is a required parameter used for identifying a DMA channel. This function
         has been designed to return a structure of type dma_chan to work with the
         DMA engine driver. Note that if DMA engine is used then drivers should be
         using the DMA engine API dma_request_slave_channel() (implemented in part 2
         of this series, "dmaengine: add helper function to request a slave DMA
         channel") which will in turn call the below function if device-tree is
         present. The aim being to have a common DMA engine interface regardless of
         whether device tree is being used.
      
      	struct dma_chan *of_dma_request_slave_channel(struct device_node *np,
      						      char *name)
      
      3. Supporting legacy devices not using DMA Engine
      
         These devices present a problem, as there may not be a uniform way to easily
         support them with regard to device tree. Ideally, these should be migrated
         to DMA engine. However, if this is not possible, then they should still be
         able to use this binding, the only constaint imposed by this implementation
         is that when requesting a DMA channel via of_dma_request_slave_channel(), it
         will return a type of dma_chan.
      
      This implementation has been tested on OMAP4430 using the kernel v3.6-rc5. I
      have validated that MMC is working on the PANDA board with this implementation.
      My development branch for testing on OMAP can be found here [5].
      
      v6: - minor corrections in DMA binding documentation
      v5: - minor update to binding documentation
          - added loop to exhaustively search for a slave channel in the case where
            there could be alternative channels available
      v4: - revert the removal of xlate function from v3
          - update the proposed binding format and APIs based upon discussions [3]
      v3: - avoid passing an xlate function and instead pass DMA engine parameters
          - define number of dma channels and requests in dma-controller node
      v2: - remove of_dma_to_resource API
          - make property #dma-cells required (no fallback anymore)
          - another check in of_dma_xlate_onenumbercell() function
      
      [1] http://article.gmane.org/gmane.linux.drivers.devicetree/12022
      [2] http://article.gmane.org/gmane.linux.ports.arm.omap/73622
      [3] http://marc.info/?l=linux-omap&m=133582085008539&w=2
      [4] http://pad.linaro.org/arm-mini-summit-2012
      [5] https://github.com/jonhunter/linux/tree/dev-dt-dma
      
      Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
      Cc: Benoit Cousson <b-cousson@ti.com>
      Cc: Stephen Warren <swarren@nvidia.com>
      Cc: Grant Likely <grant.likely@secretlab.ca>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Rob Herring <rob.herring@calxeda.com>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Vinod Koul <vinod.koul@intel.com>
      Cc: Dan Williams <djbw@fb.com>
      Reviewed-by: default avatarArnd Bergmann <arnd@arndb.de>
      Reviewed-by: default avatarNicolas Ferre <nicolas.ferre@atmel.com>
      Signed-off-by: default avatarJon Hunter <jon-hunter@ti.com>
      Reviewed-by: default avatarStephen Warren <swarren@wwwdotorg.org>
      Acked-by: default avatarRob Herring <rob.herring@calxeda.com>
      Signed-off-by: default avatarVinod Koul <vinod.koul@linux.intel.com>
      aa3da644
    • Jon Hunter's avatar
      dmaengine: add helper function to request a slave DMA channel · 9a6cecc8
      Jon Hunter authored
      Currently slave DMA channels are requested by calling dma_request_channel()
      and requires DMA clients to pass various filter parameters to obtain the
      appropriate channel.
      
      With device-tree being used by architectures such as arm and the addition of
      device-tree helper functions to extract the relevant DMA client information
      from device-tree, add a new function to request a slave DMA channel using
      device-tree. This function is currently a simple wrapper that calls the
      device-tree of_dma_request_slave_channel() function.
      
      Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
      Cc: Benoit Cousson <b-cousson@ti.com>
      Cc: Stephen Warren <swarren@nvidia.com>
      Cc: Grant Likely <grant.likely@secretlab.ca>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Rob Herring <rob.herring@calxeda.com>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Vinod Koul <vinod.koul@intel.com>
      Cc: Dan Williams <djbw@fb.com>
      Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarJon Hunter <jon-hunter@ti.com>
      Reviewed-by: default avatarStephen Warren <swarren@wwwdotorg.org>
      Acked-by: default avatarRob Herring <rob.herring@calxeda.com>
      Signed-off-by: default avatarVinod Koul <vinod.koul@linux.intel.com>
      9a6cecc8
  3. 03 Jan, 2013 10 commits
  4. 02 Jan, 2013 7 commits
    • Linus Torvalds's avatar
      Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 · 5439ca6b
      Linus Torvalds authored
      Pull ext4 bug fixes from Ted Ts'o:
       "Various bug fixes for ext4.  Perhaps the most serious bug fixed is one
        which could cause file system corruptions when performing file punch
        operations."
      
      * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
        ext4: avoid hang when mounting non-journal filesystems with orphan list
        ext4: lock i_mutex when truncating orphan inodes
        ext4: do not try to write superblock on ro remount w/o journal
        ext4: include journal blocks in df overhead calcs
        ext4: remove unaligned AIO warning printk
        ext4: fix an incorrect comment about i_mutex
        ext4: fix deadlock in journal_unmap_buffer()
        ext4: split off ext4_journalled_invalidatepage()
        jbd2: fix assertion failure in jbd2_journal_flush()
        ext4: check dioread_nolock on remount
        ext4: fix extent tree corruption caused by hole punch
      5439ca6b
    • Hugh Dickins's avatar
      mempolicy: remove arg from mpol_parse_str, mpol_to_str · a7a88b23
      Hugh Dickins authored
      Remove the unused argument (formerly no_context) from mpol_parse_str()
      and from mpol_to_str().
      Signed-off-by: default avatarHugh Dickins <hughd@google.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a7a88b23
    • Hugh Dickins's avatar
      tmpfs mempolicy: fix /proc/mounts corrupting memory · f2a07f40
      Hugh Dickins authored
      Recently I suggested using "mount -o remount,mpol=local /tmp" in NUMA
      mempolicy testing.  Very nasty.  Reading /proc/mounts, /proc/pid/mounts
      or /proc/pid/mountinfo may then corrupt one bit of kernel memory, often
      in a page table (causing "Bad swap" or "Bad page map" warning or "Bad
      pagetable" oops), sometimes in a vm_area_struct or rbnode or somewhere
      worse.  "mpol=prefer" and "mpol=prefer:Node" are equally toxic.
      
      Recent NUMA enhancements are not to blame: this dates back to 2.6.35,
      when commit e17f74af "mempolicy: don't call mpol_set_nodemask() when
      no_context" skipped mpol_parse_str()'s call to mpol_set_nodemask(),
      which used to initialize v.preferred_node, or set MPOL_F_LOCAL in flags.
      With slab poisoning, you can then rely on mpol_to_str() to set the bit
      for node 0x6b6b, probably in the next page above the caller's stack.
      
      mpol_parse_str() is only called from shmem_parse_options(): no_context
      is always true, so call it unused for now, and remove !no_context code.
      Set v.nodes or v.preferred_node or MPOL_F_LOCAL as mpol_to_str() might
      expect.  Then mpol_to_str() can ignore its no_context argument also,
      the mpol being appropriately initialized whether contextualized or not.
      Rename its no_context unused too, and let subsequent patch remove them
      (that's not needed for stable backporting, which would involve rejects).
      
      I don't understand why MPOL_LOCAL is described as a pseudo-policy:
      it's a reasonable policy which suffers from a confusing implementation
      in terms of MPOL_PREFERRED with MPOL_F_LOCAL.  I believe this would be
      much more robust if MPOL_LOCAL were recognized in switch statements
      throughout, MPOL_F_LOCAL deleted, and MPOL_PREFERRED use the (possibly
      empty) nodes mask like everyone else, instead of its preferred_node
      variant (I presume an optimization from the days before MPOL_LOCAL).
      But that would take me too long to get right and fully tested.
      Signed-off-by: default avatarHugh Dickins <hughd@google.com>
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      f2a07f40
    • Eric Wong's avatar
      epoll: prevent missed events on EPOLL_CTL_MOD · 128dd175
      Eric Wong authored
      EPOLL_CTL_MOD sets the interest mask before calling f_op->poll() to
      ensure events are not missed.  Since the modifications to the interest
      mask are not protected by the same lock as ep_poll_callback, we need to
      ensure the change is visible to other CPUs calling ep_poll_callback.
      
      We also need to ensure f_op->poll() has an up-to-date view of past
      events which occured before we modified the interest mask.  So this
      barrier also pairs with the barrier in wq_has_sleeper().
      
      This should guarantee either ep_poll_callback or f_op->poll() (or both)
      will notice the readiness of a recently-ready/modified item.
      
      This issue was encountered by Andreas Voellmy and Junchang(Jason) Wang in:
      http://thread.gmane.org/gmane.linux.kernel/1408782/Signed-off-by: default avatarEric Wong <normalperson@yhbt.net>
      Cc: Hans Verkuil <hans.verkuil@cisco.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Jonathan Corbet <corbet@lwn.net>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Davide Libenzi <davidel@xmailserver.org>
      Cc: Hans de Goede <hdegoede@redhat.com>
      Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
      Cc: David Miller <davem@davemloft.net>
      Cc: Eric Dumazet <eric.dumazet@gmail.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Andreas Voellmy <andreas.voellmy@yale.edu>
      Tested-by: default avatar"Junchang(Jason) Wang" <junchang.wang@yale.edu>
      Cc: netdev@vger.kernel.org
      Cc: linux-fsdevel@vger.kernel.org
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      128dd175
    • Aaro Koskinen's avatar
      watchdog: twl4030_wdt: add DT support · 8899b8d9
      Aaro Koskinen authored
      Add DT support for twl4030_wdt. This is needed to get twl4030_wdt to
      probe when booting with DT.
      Signed-off-by: default avatarAaro Koskinen <aaro.koskinen@iki.fi>
      Signed-off-by: default avatarWim Van Sebroeck <wim@iguana.be>
      8899b8d9
    • Aaro Koskinen's avatar
      watchdog: omap_wdt: eliminate unused variable and a compiler warning · 412b3729
      Aaro Koskinen authored
      We forgot to delete this in the commit 4f4753d9 (watchdog: omap_wdt:
      convert to devm_ functions), and as a result the following compilation
      warning was introduced:
      
      drivers/watchdog/omap_wdt.c: In function 'omap_wdt_remove':
      drivers/watchdog/omap_wdt.c:299:19: warning: unused variable 'res' [-Wunused-variable]
      Signed-off-by: default avatarAaro Koskinen <aaro.koskinen@iki.fi>
      Reviewed-by: default avatarPaul Walmsley <paul@pwsan.com>
      Signed-off-by: default avatarWim Van Sebroeck <wim@iguana.be>
      412b3729
    • Axel Lin's avatar
      watchdog: da9055: Don't update wdt_dev->timeout in da9055_wdt_set_timeout error path · 98e4a293
      Axel Lin authored
      Otherwise, WDIOC_GETTIMEOUT returns wrong value if set_timeout fails.
      This patch also removes unnecessary ret variable in da9055_wdt_ping function.
      Signed-off-by: default avatarAxel Lin <axel.lin@ingics.com>
      Signed-off-by: default avatarWim Van Sebroeck <wim@iguana.be>
      98e4a293