1. 21 5月, 2014 3 次提交
  2. 16 5月, 2014 1 次提交
  3. 05 5月, 2014 1 次提交
  4. 01 5月, 2014 1 次提交
  5. 29 4月, 2014 1 次提交
  6. 28 4月, 2014 2 次提交
    • S
      ftrace/module: Hardcode ftrace_module_init() call into load_module() · a949ae56
      Steven Rostedt (Red Hat) 提交于
      A race exists between module loading and enabling of function tracer.
      
      	CPU 1				CPU 2
      	-----				-----
        load_module()
         module->state = MODULE_STATE_COMING
      
      				register_ftrace_function()
      				 mutex_lock(&ftrace_lock);
      				 ftrace_startup()
      				  update_ftrace_function();
      				   ftrace_arch_code_modify_prepare()
      				    set_all_module_text_rw();
      				   <enables-ftrace>
      				    ftrace_arch_code_modify_post_process()
      				     set_all_module_text_ro();
      
      				[ here all module text is set to RO,
      				  including the module that is
      				  loading!! ]
      
         blocking_notifier_call_chain(MODULE_STATE_COMING);
          ftrace_init_module()
      
           [ tries to modify code, but it's RO, and fails!
             ftrace_bug() is called]
      
      When this race happens, ftrace_bug() will produces a nasty warning and
      all of the function tracing features will be disabled until reboot.
      
      The simple solution is to treate module load the same way the core
      kernel is treated at boot. To hardcode the ftrace function modification
      of converting calls to mcount into nops. This is done in init/main.c
      there's no reason it could not be done in load_module(). This gives
      a better control of the changes and doesn't tie the state of the
      module to its notifiers as much. Ftrace is special, it needs to be
      treated as such.
      
      The reason this would work, is that the ftrace_module_init() would be
      called while the module is in MODULE_STATE_UNFORMED, which is ignored
      by the set_all_module_text_ro() call.
      
      Link: http://lkml.kernel.org/r/1395637826-3312-1-git-send-email-indou.takao@jp.fujitsu.comReported-by: NTakao Indoh <indou.takao@jp.fujitsu.com>
      Acked-by: NRusty Russell <rusty@rustcorp.com.au>
      Cc: stable@vger.kernel.org # 2.6.38+
      Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      a949ae56
    • W
      word-at-a-time: avoid undefined behaviour in zero_bytemask macro · ec6931b2
      Will Deacon 提交于
      The asm-generic, big-endian version of zero_bytemask creates a mask of
      bytes preceding the first zero-byte by left shifting ~0ul based on the
      position of the first zero byte.
      
      Unfortunately, if the first (top) byte is zero, the output of
      prep_zero_mask has only the top bit set, resulting in undefined C
      behaviour as we shift left by an amount equal to the width of the type.
      As it happens, GCC doesn't manage to spot this through the call to fls(),
      but the issue remains if architectures choose to implement their shift
      instructions differently.
      
      An example would be arch/arm/ (AArch32), where LSL Rd, Rn, #32 results
      in Rd == 0x0, whilst on arch/arm64 (AArch64) LSL Xd, Xn, #64 results in
      Xd == Xn.
      
      Rather than check explicitly for the problematic shift, this patch adds
      an extra shift by 1, replacing fls with __fls. Since zero_bytemask is
      never called with a zero argument (has_zero() is used to check the data
      first), we don't need to worry about calling __fls(0), which is
      undefined.
      
      Cc: <stable@vger.kernel.org>
      Cc: Victor Kamensky <victor.kamensky@linaro.org>
      Signed-off-by: NWill Deacon <will.deacon@arm.com>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      ec6931b2
  7. 25 4月, 2014 3 次提交
    • M
      tty: Fix race condition between __tty_buffer_request_room and flush_to_ldisc · 6a20dbd6
      Manfred Schlaegl 提交于
      The race was introduced while development of linux-3.11 by
      e8437d7e and
      e9975fde.
      Originally it was found and reproduced on linux-3.12.15 and
      linux-3.12.15-rt25, by sending 500 byte blocks with 115kbaud to the
      target uart in a loop with 100 milliseconds delay.
      
      In short:
       1. The consumer flush_to_ldisc is on to remove the head tty_buffer.
       2. The producer adds a number of bytes, so that a new tty_buffer must
      	be allocated and added by __tty_buffer_request_room.
       3. The consumer removes the head tty_buffer element, without handling
      	newly committed data.
      
      Detailed example:
       * Initial buffer:
         * Head, Tail -> 0: used=250; commit=250; read=240; next=NULL
       * Consumer: ''flush_to_ldisc''
         * consumed 10 Byte
         * buffer:
           * Head, Tail -> 0: used=250; commit=250; read=250; next=NULL
      {{{
      		count = head->commit - head->read;	// count = 0
      		if (!count) {				// enter
      			// INTERRUPTED BY PRODUCER ->
      			if (head->next == NULL)
      				break;
      			buf->head = head->next;
      			tty_buffer_free(port, head);
      			continue;
      		}
      }}}
       * Producer: tty_insert_flip_... 10 bytes + tty_flip_buffer_push
         * buffer:
           * Head, Tail -> 0: used=250; commit=250; read=250; next=NULL
         * added 6 bytes: head-element filled to maximum.
           * buffer:
             * Head, Tail -> 0: used=256; commit=250; read=250; next=NULL
         * added 4 bytes: __tty_buffer_request_room is called
           * buffer:
             * Head -> 0: used=256; commit=256; read=250; next=1
             * Tail -> 1: used=4; commit=0; read=250 next=NULL
         * push (tty_flip_buffer_push)
           * buffer:
             * Head -> 0: used=256; commit=256; read=250; next=1
             * Tail -> 1: used=4; commit=4; read=250 next=NULL
       * Consumer
      {{{
      		count = head->commit - head->read;
      		if (!count) {
      			// INTERRUPTED BY PRODUCER <-
      			if (head->next == NULL)		// -> no break
      				break;
      			buf->head = head->next;
      			tty_buffer_free(port, head);
      			// ERROR: tty_buffer head freed -> 6 bytes lost
      			continue;
      		}
      }}}
      
      This patch reintroduces a spin_lock to protect this case. Perhaps later
      a lock-less solution could be found.
      Signed-off-by: NManfred Schlaegl <manfred.schlaegl@gmx.at>
      Cc: stable <stable@vger.kernel.org> # 3.11
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      6a20dbd6
    • R
      of/irq: do irq resolution in platform_get_irq · 9ec36caf
      Rob Herring 提交于
      Currently we get the following kind of errors if we try to use interrupt
      phandles to irqchips that have not yet initialized:
      
      irq: no irq domain found for /ocp/pinmux@48002030 !
      ------------[ cut here ]------------
      WARNING: CPU: 0 PID: 1 at drivers/of/platform.c:171 of_device_alloc+0x144/0x184()
      Modules linked in:
      CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.12.0-00038-g42a9708 #1012
      (show_stack+0x14/0x1c)
      (dump_stack+0x6c/0xa0)
      (warn_slowpath_common+0x64/0x84)
      (warn_slowpath_null+0x1c/0x24)
      (of_device_alloc+0x144/0x184)
      (of_platform_device_create_pdata+0x44/0x9c)
      (of_platform_bus_create+0xd0/0x170)
      (of_platform_bus_create+0x12c/0x170)
      (of_platform_populate+0x60/0x98)
      
      This is because we're wrongly trying to populate resources that are not
      yet available. It's perfectly valid to create irqchips dynamically, so
      let's fix up the issue by resolving the interrupt resources when
      platform_get_irq is called.
      
      And then we also need to accept the fact that some irqdomains do not
      exist that early on, and only get initialized later on. So we can
      make the current WARN_ON into just into a pr_debug().
      
      We still attempt to populate irq resources when we create the devices.
      This allows current drivers which don't use platform_get_irq to continue
      to function. Once all drivers are fixed, this code can be removed.
      Suggested-by: NRussell King <linux@arm.linux.org.uk>
      Signed-off-by: NRob Herring <robh@kernel.org>
      Signed-off-by: NTony Lindgren <tony@atomide.com>
      Tested-by: NTony Lindgren <tony@atomide.com>
      Cc: stable@vger.kernel.org # v3.10+
      Signed-off-by: NGrant Likely <grant.likely@linaro.org>
      9ec36caf
    • G
      phy: core: make NULL a valid phy reference if !CONFIG_GENERIC_PHY · 2b97789f
      Grygorii Strashko 提交于
      This fixes a regression on Keystone 2 platforms caused by patch
      57303488
      "usb: dwc3: adapt dwc3 core to use Generic PHY Framework" which adds
      optional support of generic phy in DWC3 core.
      
      On Keystone 2 platforms the USB is not working now because
      CONFIG_GENERIC_PHY isn't set and, as result, Generic PHY APIs stubs
      return -ENOSYS always. The log shows:
       dwc3 2690000.dwc3: failed to initialize core
       dwc3: probe of 2690000.dwc3 failed with error -38
      
      Hence, fix it by making NULL a valid phy reference in Generic PHY
      APIs stubs in the same way as it was done by the patch
      04c2faca "drivers: phy: Make NULL
      a valid phy reference".
      Acked-by: NFelipe Balbi <balbi@ti.com>
      Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
      Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
      Signed-off-by: NKishon Vijay Abraham I <kishon@ti.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      2b97789f
  8. 24 4月, 2014 2 次提交
  9. 23 4月, 2014 9 次提交
  10. 22 4月, 2014 6 次提交
    • J
      locks: rename file-private locks to "open file description locks" · 0d3f7a2d
      Jeff Layton 提交于
      File-private locks have been merged into Linux for v3.15, and *now*
      people are commenting that the name and macro definitions for the new
      file-private locks suck.
      
      ...and I can't even disagree. The names and command macros do suck.
      
      We're going to have to live with these for a long time, so it's
      important that we be happy with the names before we're stuck with them.
      The consensus on the lists so far is that they should be rechristened as
      "open file description locks".
      
      The name isn't a big deal for the kernel, but the command macros are not
      visually distinct enough from the traditional POSIX lock macros. The
      glibc and documentation folks are recommending that we change them to
      look like F_OFD_{GETLK|SETLK|SETLKW}. That lessens the chance that a
      programmer will typo one of the commands wrong, and also makes it easier
      to spot this difference when reading code.
      
      This patch makes the following changes that I think are necessary before
      v3.15 ships:
      
      1) rename the command macros to their new names. These end up in the uapi
         headers and so are part of the external-facing API. It turns out that
         glibc doesn't actually use the fcntl.h uapi header, but it's hard to
         be sure that something else won't. Changing it now is safest.
      
      2) make the the /proc/locks output display these as type "OFDLCK"
      
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Christoph Hellwig <hch@infradead.org>
      Cc: Carlos O'Donell <carlos@redhat.com>
      Cc: Stefan Metzmacher <metze@samba.org>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Frank Filz <ffilzlnx@mindspring.com>
      Cc: Theodore Ts'o <tytso@mit.edu>
      Signed-off-by: NJeff Layton <jlayton@redhat.com>
      0d3f7a2d
    • D
      drm: kill drm_bus->bus_type · 42b21049
      Daniel Vetter 提交于
      Completely unused. Hooray, midlayer mistakes that didn't cause work to
      undo!
      
      v2: Rebase on top of the recent tegra changes which added a host1x drm
      bus.
      Reviewed-by: NThierry Reding <treding@nvidia.com>
      Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      42b21049
    • D
      drm: remove drm_dev_to_irq from drivers · ebfa4324
      Daniel Vetter 提交于
      Only used in some legacy pci drivers, and dereferencing the PCI irq is
      actually shorter ...
      
      Since this removes all users for drm_dev_to_irq from the tree except
      in drm_irq.c, move the inline helper in there. It'll disappear soon,
      too.
      
      v2: Polish commit message (Thierry)
      Reviewed-by: NThierry Reding <treding@nvidia.com>
      Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      ebfa4324
    • D
      drm/pci: fold in irq_by_busid support · eaaf8f0f
      Daniel Vetter 提交于
      This is a ums-only ioctl, and we've only ever supported ums (at least
      in upstream) on pci devices. So no point in keeping that piece of
      legacy logic abstracted within the drm bus driver.
      
      To keep things work without CONFIG_PCI also add a dummy ioctl.
      
      v2: Block the irq_by_busid ioctl for modeset drivers.
      
      v3: Spelling/whitespace polish (Thierry)
      Reviewed-by: NThierry Reding <treding@nvidia.com>
      Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      eaaf8f0f
    • A
      drm: make mode_valid callback optional · f9b0e251
      Andrzej Hajda 提交于
      Many drm connectors do not need mode validation.
      The patch makes this callback optional and removes dumb implementations.
      
      v2: Rebase:
      - imx move to a shared (but still dummy) ->mode_valid implementation.
      - probe helpers have been extracted to drm_probe_helper.c
      
      Signed-off-by: Andrzej Hajda <a.hajda@samsung.com> (v1)
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      f9b0e251
    • V
      drm/edid: Fill PAR in AVI infoframe based on CEA mode list · 0967e6a5
      Vandana Kannan 提交于
      Populate PAR in infoframe structure. If there is a user setting for PAR, then
      that value is set. Else, value is taken from CEA mode list if VIC is found.
      Else, PAR is calculated from resolution. If none of these conditions are
      satisfied, PAR is NONE as per initialization.
      
      v2: Removed the part which sets PAR according to user input, based on
      Daniel's review comments.
      
      A separate patch will be submitted to create a property that would enable a
      user space app to set aspect ratio for AVI infoframe.
      
      v2: Removed the part which sets PAR according to user input, based on
      Daniel's review comments.
      
      v3: Removed calculation of PAR for non-CEA modes as per discussion with
      Ville.
      
      A separate patch will be submitted to create a property that would enable a
      user space app to set aspect ratio for AVI infoframe.
      Signed-off-by: NVandana Kannan <vandana.kannan@intel.com>
      Cc: Jesse Barnes <jesse.barnes@intel.com>
      Cc: Vijay Purushothaman <vijay.a.purushothaman@intel.com>
      Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
      Cc: intel-gfx@lists.freedesktop.org
      Reviewed-by: NJesse Barnes <jbarnes@virtuousgeek.org>
      [danvet: Squash in fixup for htmldocs.]
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      0967e6a5
  11. 20 4月, 2014 2 次提交
    • H
      Input: Add INPUT_PROP_TOPBUTTONPAD device property · f37c0134
      Hans de Goede 提交于
      On some newer laptops with a trackpoint the physical buttons for the
      trackpoint have been removed to allow for a larger touchpad. On these
      laptops the buttonpad has clearly marked areas on the top which are to be
      used as trackpad buttons.
      
      Users of the event device-node need to know about this, so that they can
      properly interpret BTN_LEFT events as being a left / right / middle click
      depending on where on the button pad the clicking finger is.
      
      This commits adds a INPUT_PROP_TOPBUTTONPAD device property which drivers
      for such buttonpads will use to signal to the user that this buttonpad not
      only has the normal bottom button area, but also a top button area.
      Signed-off-by: NHans de Goede <hdegoede@redhat.com>
      Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
      f37c0134
    • H
      Input: serio - add firmware_id sysfs attribute · 0456c66f
      Hans de Goede 提交于
      serio devices exposed via platform firmware interfaces such as ACPI may
      provide additional identifying information of use to userspace.
      
      We don't associate the serio devices with the firmware device (we don't
      set it as parent), so there's no way for userspace to make use of this
      information.
      
      We cannot change the parent for serio devices instantiated though a
      firmware interface as that would break suspend / resume ordering.
      
      Therefore this patch adds a new firmware_id sysfs attribute so that
      userspace can get a string from there with any additional identifying
      information the firmware interface may provide.
      Signed-off-by: NHans de Goede <hdegoede@redhat.com>
      Acked-by: NPeter Hutterer <peter.hutterer@who-t.net>
      Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
      0456c66f
  12. 19 4月, 2014 5 次提交
    • M
      mm: use paravirt friendly ops for NUMA hinting ptes · 29c77870
      Mel Gorman 提交于
      David Vrabel identified a regression when using automatic NUMA balancing
      under Xen whereby page table entries were getting corrupted due to the
      use of native PTE operations.  Quoting him
      
      	Xen PV guest page tables require that their entries use machine
      	addresses if the preset bit (_PAGE_PRESENT) is set, and (for
      	successful migration) non-present PTEs must use pseudo-physical
      	addresses.  This is because on migration MFNs in present PTEs are
      	translated to PFNs (canonicalised) so they may be translated back
      	to the new MFN in the destination domain (uncanonicalised).
      
      	pte_mknonnuma(), pmd_mknonnuma(), pte_mknuma() and pmd_mknuma()
      	set and clear the _PAGE_PRESENT bit using pte_set_flags(),
      	pte_clear_flags(), etc.
      
      	In a Xen PV guest, these functions must translate MFNs to PFNs
      	when clearing _PAGE_PRESENT and translate PFNs to MFNs when setting
      	_PAGE_PRESENT.
      
      His suggested fix converted p[te|md]_[set|clear]_flags to using
      paravirt-friendly ops but this is overkill.  He suggested an alternative
      of using p[te|md]_modify in the NUMA page table operations but this is
      does more work than necessary and would require looking up a VMA for
      protections.
      
      This patch modifies the NUMA page table operations to use paravirt
      friendly operations to set/clear the flags of interest.  Unfortunately
      this will take a performance hit when updating the PTEs on
      CONFIG_PARAVIRT but I do not see a way around it that does not break
      Xen.
      Signed-off-by: NMel Gorman <mgorman@suse.de>
      Acked-by: NDavid Vrabel <david.vrabel@citrix.com>
      Tested-by: NDavid Vrabel <david.vrabel@citrix.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Peter Anvin <hpa@zytor.com>
      Cc: Fengguang Wu <fengguang.wu@intel.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Steven Noonan <steven@uplinklabs.net>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
      Cc: Cyrill Gorcunov <gorcunov@gmail.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      29c77870
    • P
      wait: explain the shadowing and type inconsistencies · 8b32201d
      Peter Zijlstra 提交于
      Stick in a comment before someone else tries to fix the sparse warning
      this generates.
      Suggested-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/n/tip-o2ro6f3vkxklni0bc8f7m68s@git.kernel.orgSigned-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      8b32201d
    • V
      Shiraz has moved · 9cc23682
      Viresh Kumar 提交于
      shiraz.hashim@st.com email-id doesn't exist anymore as he has left the
      company.  Replace ST's id with shiraz.linux.kernel@gmail.com.
      
      It also updates .mailmap file to fix address for 'git shortlog'.
      Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
      Cc: Shiraz Hashim <shiraz.linux.kernel@gmail.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      9cc23682
    • V
      net: sctp: cache auth_enable per endpoint · b14878cc
      Vlad Yasevich 提交于
      Currently, it is possible to create an SCTP socket, then switch
      auth_enable via sysctl setting to 1 and crash the system on connect:
      
      Oops[#1]:
      CPU: 0 PID: 0 Comm: swapper Not tainted 3.14.1-mipsgit-20140415 #1
      task: ffffffff8056ce80 ti: ffffffff8055c000 task.ti: ffffffff8055c000
      [...]
      Call Trace:
      [<ffffffff8043c4e8>] sctp_auth_asoc_set_default_hmac+0x68/0x80
      [<ffffffff8042b300>] sctp_process_init+0x5e0/0x8a4
      [<ffffffff8042188c>] sctp_sf_do_5_1B_init+0x234/0x34c
      [<ffffffff804228c8>] sctp_do_sm+0xb4/0x1e8
      [<ffffffff80425a08>] sctp_endpoint_bh_rcv+0x1c4/0x214
      [<ffffffff8043af68>] sctp_rcv+0x588/0x630
      [<ffffffff8043e8e8>] sctp6_rcv+0x10/0x24
      [<ffffffff803acb50>] ip6_input+0x2c0/0x440
      [<ffffffff8030fc00>] __netif_receive_skb_core+0x4a8/0x564
      [<ffffffff80310650>] process_backlog+0xb4/0x18c
      [<ffffffff80313cbc>] net_rx_action+0x12c/0x210
      [<ffffffff80034254>] __do_softirq+0x17c/0x2ac
      [<ffffffff800345e0>] irq_exit+0x54/0xb0
      [<ffffffff800075a4>] ret_from_irq+0x0/0x4
      [<ffffffff800090ec>] rm7k_wait_irqoff+0x24/0x48
      [<ffffffff8005e388>] cpu_startup_entry+0xc0/0x148
      [<ffffffff805a88b0>] start_kernel+0x37c/0x398
      Code: dd0900b8  000330f8  0126302d <dcc60000> 50c0fff1  0047182a  a48306a0
      03e00008  00000000
      ---[ end trace b530b0551467f2fd ]---
      Kernel panic - not syncing: Fatal exception in interrupt
      
      What happens while auth_enable=0 in that case is, that
      ep->auth_hmacs is initialized to NULL in sctp_auth_init_hmacs()
      when endpoint is being created.
      
      After that point, if an admin switches over to auth_enable=1,
      the machine can crash due to NULL pointer dereference during
      reception of an INIT chunk. When we enter sctp_process_init()
      via sctp_sf_do_5_1B_init() in order to respond to an INIT chunk,
      the INIT verification succeeds and while we walk and process
      all INIT params via sctp_process_param() we find that
      net->sctp.auth_enable is set, therefore do not fall through,
      but invoke sctp_auth_asoc_set_default_hmac() instead, and thus,
      dereference what we have set to NULL during endpoint
      initialization phase.
      
      The fix is to make auth_enable immutable by caching its value
      during endpoint initialization, so that its original value is
      being carried along until destruction. The bug seems to originate
      from the very first days.
      
      Fix in joint work with Daniel Borkmann.
      Reported-by: NJoshua Kinard <kumba@gentoo.org>
      Signed-off-by: NVlad Yasevich <vyasevic@redhat.com>
      Signed-off-by: NDaniel Borkmann <dborkman@redhat.com>
      Acked-by: NNeil Horman <nhorman@tuxdriver.com>
      Tested-by: NJoshua Kinard <kumba@gentoo.org>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      b14878cc
    • D
      libata/ahci: accommodate tag ordered controllers · 8a4aeec8
      Dan Williams 提交于
      The AHCI spec allows implementations to issue commands in tag order
      rather than FIFO order:
      
      	5.3.2.12 P:SelectCmd
      	HBA sets pSlotLoc = (pSlotLoc + 1) mod (CAP.NCS + 1)
      	or HBA selects the command to issue that has had the
      	PxCI bit set to '1' longer than any other command
      	pending to be issued.
      
      The result is that commands posted sequentially (time-wise) may play out
      of sequence when issued by hardware.
      
      This behavior has likely been hidden by drives that arrange for commands
      to complete in issue order.  However, it appears recent drives (two from
      different vendors that we have found so far) inflict out-of-order
      completions as a matter of course.  So, we need to take care to maintain
      ordered submission, otherwise we risk triggering a drive to fall out of
      sequential-io automation and back to random-io processing, which incurs
      large latency and degrades throughput.
      
      This issue was found in simple benchmarks where QD=2 seq-write
      performance was 30-50% *greater* than QD=32 seq-write performance.
      
      Tagging for -stable and making the change globally since it has a low
      risk-to-reward ratio.  Also, word is that recent versions of an unnamed
      OS also does it this way now.  So, drives in the field are already
      experienced with this tag ordering scheme.
      
      Cc: <stable@vger.kernel.org>
      Cc: Dave Jiang <dave.jiang@intel.com>
      Cc: Ed Ciechanowski <ed.ciechanowski@intel.com>
      Reviewed-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>
      Signed-off-by: NDan Williams <dan.j.williams@intel.com>
      Signed-off-by: NTejun Heo <tj@kernel.org>
      8a4aeec8
  13. 18 4月, 2014 4 次提交
    • T
      regulator: core: Return error in get optional stub · df7926ff
      Tim Kryger 提交于
      Drivers that call regulator_get_optional are tolerant to the absence of
      that regulator.  By modifying the value returned from the stub function
      to match that seen when a regulator isn't present, callers can wrap the
      regulator logic with an IS_ERR based conditional even if they happen to
      call regulator_is_supported_voltage.  This improves efficiency as well
      as eliminates the possibility for a very subtle bug.
      Signed-off-by: NTim Kryger <tim.kryger@linaro.org>
      Reviewed-by: NAlex Elder <elder@linaro.org>
      Signed-off-by: NMark Brown <broonie@linaro.org>
      df7926ff
    • A
      of: add empty of_find_node_by_path() for !OF · 20cd477c
      Alexander Shiyan 提交于
      Add an empty version of of_find_node_by_path().
      This fixes following build error for asoc tree:
      sound/soc/fsl/fsl_ssi.c: In function 'fsl_ssi_probe':
      sound/soc/fsl/fsl_ssi.c:1471:2: error: implicit declaration of function 'of_find_node_by_path' [-Werror=implicit-function-declaration]
        sprop = of_get_property(of_find_node_by_path("/"), "compatible", NULL);
      Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
      Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
      Signed-off-by: NRob Herring <robh@kernel.org>
      20cd477c
    • D
      drm: Split out drm_probe_helper.c from drm_crtc_helper.c · 8d754544
      Daniel Vetter 提交于
      This is leftover stuff from my previous doc round which I kinda wanted
      to do but didn't yet due to rebase hell.
      
      The modeset helpers and the probing helpers a independent and e.g.
      i915 uses the probing stuff but has its own modeset infrastructure. It
      hence makes to split this up. While at it add a DOC: comment for the
      probing libraray.
      
      It would be rather neat to pull some of the DocBook documenting these
      two helpers into in-line DOC: comments. But unfortunately kerneldoc
      doesn't support markdown or something similar to make nice-looking
      documentation, so the current state is better.
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      Signed-off-by: NDave Airlie <airlied@redhat.com>
      8d754544
    • T
      genirq: Allow forcing cpu affinity of interrupts · 01f8fa4f
      Thomas Gleixner 提交于
      The current implementation of irq_set_affinity() refuses rightfully to
      route an interrupt to an offline cpu.
      
      But there is a special case, where this is actually desired. Some of
      the ARM SoCs have per cpu timers which require setting the affinity
      during cpu startup where the cpu is not yet in the online mask.
      
      If we can't do that, then the local timer interrupt for the about to
      become online cpu is routed to some random online cpu.
      
      The developers of the affected machines tried to work around that
      issue, but that results in a massive mess in that timer code.
      
      We have a yet unused argument in the set_affinity callbacks of the irq
      chips, which I added back then for a similar reason. It was never
      required so it got not used. But I'm happy that I never removed it.
      
      That allows us to implement a sane handling of the above scenario. So
      the affected SoC drivers can add the required force handling to their
      interrupt chip, switch the timer code to irq_force_affinity() and
      things just work.
      
      This does not affect any existing user of irq_set_affinity().
      
      Tagged for stable to allow a simple fix of the affected SoC clock
      event drivers.
      Reported-and-tested-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Cc: Kyungmin Park <kyungmin.park@samsung.com>
      Cc: Marek Szyprowski <m.szyprowski@samsung.com>
      Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
      Cc: Tomasz Figa <t.figa@samsung.com>,
      Cc: Daniel Lezcano <daniel.lezcano@linaro.org>,
      Cc: Kukjin Kim <kgene.kim@samsung.com>
      Cc: linux-arm-kernel@lists.infradead.org,
      Cc: stable@vger.kernel.org
      Link: http://lkml.kernel.org/r/20140416143315.717251504@linutronix.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
      01f8fa4f