1. 28 Jun, 2017 4 commits
    • Lv Zheng's avatar
      ACPI / EC: Add support to skip boot stage DSDT probe · c712bb58
      Lv Zheng authored
      We prepared _INI/_STA methods for \_SB, \_SB.PCI0, \_SB.LID0 and
      \_SB.EC, _HID(PNP0C09)/_CRS/_GPE for \_SB.EC to poke Windows behavior
      with qemu, we got the following execution sequence:
      
       \_SB._INI
       \_SB.PCI0._STA
       \_SB.LID0._STA
       \_SB.EC._STA
       \_SB.PCI0._INI
       \_SB.LID0._INI
       \_SB.EC._INI
      
      There is no extra DSDT EC device enumeration process occurring before
      the main ACPI device enumeration process. That means acpi_ec_dsdt_probe()
      is not Windows-compatible.
      
      Tracking back, it was added by the following commit:
      
        Commit: c5279dee
        Subject: ACPI: EC: Add some basic check for ECDT data
      
      but that commit was misguided.
      
      Why we shouldn't enumerate DSDT EC before the main ACPI device
      enumeration?
      
      The only way to know if the DSDT EC is valid would be to evaluate its
      _STA control method, but it's not safe to evaluate this control method
      that early and out of the ACPI enumeration process, because _STA may
      refer to entities (such as resources or ACPI device objects) that may
      not have been initialized before OSPM starts to enumerate them via
      the main ACPI device enumeration.
      
      But after we had reverted back to the expected behavior, a regression
      was reported.  On that platform, there is no ECDT, but the platform
      control methods access EC operation region earlier than Linux expects
      causing some ACPI method execution errors. For this reason, we just
      go back to old behavior to still probe DSDT EC as the boot EC.
      
      However, that turns out to lead to yet another functional breakage
      and in order to work around all of the problems, we skip boot stage
      DSDT probe when the ECDT exists so that a later quirk can always use
      correct ECDT GPE setting.
      
      Link: http://bugzilla.kernel.org/show_bug.cgi?id=11880
      Link: http://bugzilla.kernel.org/show_bug.cgi?id=119261
      Link: http://bugzilla.kernel.org/show_bug.cgi?id=195651Tested-by: default avatarDaniel Drake <drake@endlessm.com>
      Signed-off-by: default avatarLv Zheng <lv.zheng@intel.com>
      [ rjw: Changelog & comments massage ]
      Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      c712bb58
    • Lv Zheng's avatar
      ACPI / EC: Enhance boot EC sanity check · ae56c9fd
      Lv Zheng authored
      It's reported that some buggy BIOS tables can contain 2 DSDT ECs, one of
      them is invalid but acpi_ec_dsdt_probe() fails to pick the valid one.
      This patch simply enhances sanity checks in ec_parse_device() as a
      workaround to skip probing wrong namespace ECs.
      
      Link: https://bugzilla.kernel.org/show_bug.cgi?id=195651Tested-by: default avatarDaniel Drake <drake@endlessm.com>
      Signed-off-by: default avatarLv Zheng <lv.zheng@intel.com>
      Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      ae56c9fd
    • Lv Zheng's avatar
      ACPI: EC: Fix EC command visibility for dynamic debug · 4625d752
      Lv Zheng authored
      acpi_ec_cmd_string() currently is only enabled for "DEBUG" macro, but users
      trend to use CONFIG_DYNAMIC_DEBUG and enable ec.c pr_debug() print-outs by
      "dyndbg='file ec.c +p'". In this use case, all command names are turned
      into UNDEF and the log is confusing. This affects bugzilla triage work.
      
      This patch fixes this issue by enabling acpi_ec_cmd_string() for
      CONFIG_DYNAMIC_DEBUG.
      Tested-by: default avatarWang Wendy <wendy.wang@intel.com>
      Tested-by: default avatarFeng Chenzhou <chenzhoux.feng@intel.com>
      Signed-off-by: default avatarLv Zheng <lv.zheng@intel.com>
      Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      4625d752
    • Lv Zheng's avatar
      ACPI: EC: Fix an EC event IRQ storming issue · 1ab69f27
      Lv Zheng authored
      The EC event IRQ (SCI_EVT) can only be handled by submitting QR_EC. As the
      EC driver handles SCI_EVT in a workqueue, after SCI_EVT is flagged and
      before QR_EC is submitted, there is a period risking IRQ storming. EC IRQ
      must be masked for this period but linux EC driver never does so.
      
      No end user notices the IRQ storming and no developer fixes this known
      issue because:
      
       1. The EC IRQ is always edge triggered GPE, and
       2. The kernel can execute no-op EC IRQ handler very fast.
      
      For edge-triggered EC GPE platforms, it is only reported of post-resume EC
      event lost issues, there won't be an IRQ storming. For level triggered EC
      GPE platforms, fortunately the kernel is always fast enough to execute such
      a no-op EC IRQ handler so that the IRQ handler won't be accumulated to
      starve the task contexts, causing a real IRQ storming.
      
      But the IRQ storming actually can still happen when:
      
       1. The EC IRQ performs like level triggered GPE, and
       2. The kernel EC debugging log is turned on but the console is slow enough.
      
      There are more and more platforms using EC GPE as wake GPE where the EC GPE
      is likely designed as level triggered. Then when EC debugging log is
      enabled, the EC IRQ handler is no longer a no-op but dumps IRQ status to
      the consoles. If the consoles are slow enough, the EC IRQs can arrive much
      faster than executing the handler. Finally the accumulated EC event IRQ
      handlers starve the task contexts, causing the IRQ storming to occur, and
      the kernel hangs can be observed during boot/resume.
      
      This patch fixes this issue by masking EC IRQ for this period:
      
       1. Begins when there is an SCI_EVT IRQ pending, and
       2. Ends when there is a QR_EC completed (SCI_EVT acknowledged).
      Tested-by: default avatarWang Wendy <wendy.wang@intel.com>
      Tested-by: default avatarFeng Chenzhou <chenzhoux.feng@intel.com>
      Signed-off-by: default avatarLv Zheng <lv.zheng@intel.com>
      Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
      1ab69f27
  2. 26 Jun, 2017 1 commit
  3. 25 Jun, 2017 6 commits
  4. 24 Jun, 2017 11 commits
  5. 23 Jun, 2017 15 commits
  6. 22 Jun, 2017 3 commits
    • Randy Dunlap's avatar
      kconfig: fix sparse warnings in nconfig · ad818106
      Randy Dunlap authored
      Fix sparse warnings in scripts/kconfig/nconf* ('make nconfig'):
      
      ../scripts/kconfig/nconf.c:1071:32: warning: Using plain integer as NULL pointer
      ../scripts/kconfig/nconf.c:1238:30: warning: Using plain integer as NULL pointer
      ../scripts/kconfig/nconf.c:511:51: warning: Using plain integer as NULL pointer
      ../scripts/kconfig/nconf.c:1460:6: warning: symbol 'setup_windows' was not declared. Should it be static?
      ../scripts/kconfig/nconf.c:274:12: warning: symbol 'current_instructions' was not declared. Should it be static?
      ../scripts/kconfig/nconf.c:308:22: warning: symbol 'function_keys' was not declared. Should it be static?
      ../scripts/kconfig/nconf.gui.c:132:17: warning: non-ANSI function declaration of function 'set_colors'
      ../scripts/kconfig/nconf.gui.c:195:24: warning: Using plain integer as NULL pointer
      
      nconf.gui.o before/after files are the same.
      nconf.o before/after files are the same until the 'static' function
      declarations are added.
      Signed-off-by: default avatarRandy Dunlap <rdunlap@infradead.org>
      Signed-off-by: default avatarMasahiro Yamada <yamada.masahiro@socionext.com>
      ad818106
    • Björn Töpel's avatar
      perf probe: Fix probe definition for inlined functions · 7598f8bc
      Björn Töpel authored
      In commit 613f050d ("perf probe: Fix to probe on gcc generated
      functions in modules"), the offset from symbol is, incorrectly, added
      to the trace point address. This leads to incorrect probe trace points
      for inlined functions and when using relative line number on symbols.
      
      Prior this patch:
        $ perf probe -m nf_nat -D in_range
        p:probe/in_range nf_nat:in_range.isra.9+0
        $ perf probe -m i40e -D i40e_clean_rx_irq
        p:probe/i40e_clean_rx_irq i40e:i40e_napi_poll+2212
        $ perf probe -m i40e -D i40e_clean_rx_irq:16
        p:probe/i40e_clean_rx_irq i40e:i40e_lan_xmit_frame+626
      
      After:
        $ perf probe -m nf_nat -D in_range
        p:probe/in_range nf_nat:in_range.isra.9+0
        $ perf probe -m i40e -D i40e_clean_rx_irq
        p:probe/i40e_clean_rx_irq i40e:i40e_napi_poll+1106
        $ perf probe -m i40e -D i40e_clean_rx_irq:16
        p:probe/i40e_clean_rx_irq i40e:i40e_napi_poll+2665
      
      Committer testing:
      
      Using 'pfunct', a tool found in the 'dwarves' package [1], one can ask what are
      the functions that while not being explicitely marked as inline, were inlined
      by the compiler:
      
        # pfunct --cc_inlined /lib/modules/4.12.0-rc4+/kernel/drivers/net/ethernet/intel/e1000e/e1000e.ko | head
        __ew32
        e1000_regdump
        e1000e_dump_ps_pages
        e1000_desc_unused
        e1000e_systim_to_hwtstamp
        e1000e_rx_hwtstamp
        e1000e_update_rdt_wa
        e1000e_update_tdt_wa
        e1000_put_txbuf
        e1000_consume_page
      
      Then ask 'perf probe' to produce the kprobe_tracer probe definitions for two of
      them:
      
        # perf probe -m e1000e -D e1000e_rx_hwtstamp
        p:probe/e1000e_rx_hwtstamp e1000e:e1000_receive_skb+74
      
        # perf probe -m e1000e -D e1000_consume_page
        p:probe/e1000_consume_page e1000e:e1000_clean_jumbo_rx_irq+876
        p:probe/e1000_consume_page_1 e1000e:e1000_clean_jumbo_rx_irq+1506
        p:probe/e1000_consume_page_2 e1000e:e1000_clean_rx_irq_ps+1074
      
      Now lets concentrate on the 'e1000_consume_page' one, that was inlined twice in
      e1000_clean_jumbo_rx_irq(), lets see what readelf says about the DWARF tags for
      that function:
      
        $ readelf -wi /lib/modules/4.12.0-rc4+/kernel/drivers/net/ethernet/intel/e1000e/e1000e.ko
        <SNIP>
        <1><13e27b>: Abbrev Number: 121 (DW_TAG_subprogram)
          <13e27c>   DW_AT_name        : (indirect string, offset: 0xa8945): e1000_clean_jumbo_rx_irq
          <13e287>   DW_AT_low_pc      : 0x17a30
        <3><13e6ef>: Abbrev Number: 119 (DW_TAG_inlined_subroutine)
          <13e6f0>   DW_AT_abstract_origin: <0x13ed2c>
          <13e6f4>   DW_AT_low_pc      : 0x17be6
        <SNIP>
        <1><13ed2c>: Abbrev Number: 142 (DW_TAG_subprogram)
           <13ed2e>   DW_AT_name        : (indirect string, offset: 0xa54c3): e1000_consume_page
      
      So, the first time in e1000_clean_jumbo_rx_irq() where e1000_consume_page() is
      inlined is at PC 0x17be6, which subtracted from e1000_clean_jumbo_rx_irq()'s
      address, gives us the offset we should use in the probe definition:
      
        0x17be6 - 0x17a30 = 438
      
      but above we have 876, which is twice as much.
      
      Lets see the second inline expansion of e1000_consume_page() in
      e1000_clean_jumbo_rx_irq():
      
        <3><13e86e>: Abbrev Number: 119 (DW_TAG_inlined_subroutine)
          <13e86f>   DW_AT_abstract_origin: <0x13ed2c>
          <13e873>   DW_AT_low_pc      : 0x17d21
      
        0x17d21 - 0x17a30 = 753
      
      So we where adding it at twice the offset from the containing function as we
      should.
      
      And then after this patch:
      
        # perf probe -m e1000e -D e1000e_rx_hwtstamp
        p:probe/e1000e_rx_hwtstamp e1000e:e1000_receive_skb+37
      
        # perf probe -m e1000e -D e1000_consume_page
        p:probe/e1000_consume_page e1000e:e1000_clean_jumbo_rx_irq+438
        p:probe/e1000_consume_page_1 e1000e:e1000_clean_jumbo_rx_irq+753
        p:probe/e1000_consume_page_2 e1000e:e1000_clean_jumbo_rx_irq+1353
        #
      
      Which matches the two first expansions and shows that because we were
      doubling the offset it would spill over the next function:
      
        readelf -sw /lib/modules/4.12.0-rc4+/kernel/drivers/net/ethernet/intel/e1000e/e1000e.ko
         673: 0000000000017a30  1626 FUNC    LOCAL  DEFAULT    2 e1000_clean_jumbo_rx_irq
         674: 0000000000018090  2013 FUNC    LOCAL  DEFAULT    2 e1000_clean_rx_irq_ps
      
      This is the 3rd inline expansion of e1000_consume_page() in
      e1000_clean_jumbo_rx_irq():
      
         <3><13ec77>: Abbrev Number: 119 (DW_TAG_inlined_subroutine)
          <13ec78>   DW_AT_abstract_origin: <0x13ed2c>
          <13ec7c>   DW_AT_low_pc      : 0x17f79
      
        0x17f79 - 0x17a30 = 1353
      
       So:
      
         0x17a30 + 2 * 1353 = 0x184c2
      
        And:
      
         0x184c2 - 0x18090 = 1074
      
      Which explains the bogus third expansion for e1000_consume_page() to end up at:
      
         p:probe/e1000_consume_page_2 e1000e:e1000_clean_rx_irq_ps+1074
      
      All fixed now :-)
      
      [1] https://git.kernel.org/pub/scm/devel/pahole/pahole.git/Signed-off-by: default avatarBjörn Töpel <bjorn.topel@intel.com>
      Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      Acked-by: default avatarMagnus Karlsson <magnus.karlsson@intel.com>
      Acked-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
      Cc: stable@vger.kernel.org
      Fixes: 613f050d ("perf probe: Fix to probe on gcc generated functions in modules")
      Link: http://lkml.kernel.org/r/20170621164134.5701-1-bjorn.topel@gmail.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      7598f8bc
    • Linus Torvalds's avatar
      Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6 · a38371cb
      Linus Torvalds authored
      Pull cifs fixes from Steve French:
       "Various small fixes for stable"
      
      * 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
        CIFS: Fix some return values in case of error in 'crypt_message'
        cifs: remove redundant return in cifs_creation_time_get
        CIFS: Improve readdir verbosity
        CIFS: check if pages is null rather than bv for a failed allocation
        CIFS: Set ->should_dirty in cifs_user_readv()
      a38371cb