1. 12 Jul, 2016 7 commits
    • Jiri Slaby's avatar
      base: make module_create_drivers_dir race-free · b8f04bf4
      Jiri Slaby authored
      [ Upstream commit 7e1b1fc4 ]
      
      Modules which register drivers via standard path (driver_register) in
      parallel can cause a warning:
      WARNING: CPU: 2 PID: 3492 at ../fs/sysfs/dir.c:31 sysfs_warn_dup+0x62/0x80
      sysfs: cannot create duplicate filename '/module/saa7146/drivers'
      Modules linked in: hexium_gemini(+) mxb(+) ...
      ...
      Call Trace:
      ...
       [<ffffffff812e63a2>] sysfs_warn_dup+0x62/0x80
       [<ffffffff812e6487>] sysfs_create_dir_ns+0x77/0x90
       [<ffffffff8140f2c4>] kobject_add_internal+0xb4/0x340
       [<ffffffff8140f5b8>] kobject_add+0x68/0xb0
       [<ffffffff8140f631>] kobject_create_and_add+0x31/0x70
       [<ffffffff8157a703>] module_add_driver+0xc3/0xd0
       [<ffffffff8155e5d4>] bus_add_driver+0x154/0x280
       [<ffffffff815604c0>] driver_register+0x60/0xe0
       [<ffffffff8145bed0>] __pci_register_driver+0x60/0x70
       [<ffffffffa0273e14>] saa7146_register_extension+0x64/0x90 [saa7146]
       [<ffffffffa0033011>] hexium_init_module+0x11/0x1000 [hexium_gemini]
      ...
      
      As can be (mostly) seen, driver_register causes this call sequence:
        -> bus_add_driver
          -> module_add_driver
            -> module_create_drivers_dir
      The last one creates "drivers" directory in /sys/module/<...>. When
      this is done in parallel, the directory is attempted to be created
      twice at the same time.
      
      This can be easily reproduced by loading mxb and hexium_gemini in
      parallel:
      while :; do
        modprobe mxb &
        modprobe hexium_gemini
        wait
        rmmod mxb hexium_gemini saa7146_vv saa7146
      done
      
      saa7146 calls pci_register_driver for both mxb and hexium_gemini,
      which means /sys/module/saa7146/drivers is to be created for both of
      them.
      
      Fix this by a new mutex in module_create_drivers_dir which makes the
      test-and-create "drivers" dir atomic.
      
      I inverted the condition and removed 'return' to avoid multiple
      unlocks or a goto.
      Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      Fixes: fe480a26 (Modules: only add drivers/ direcory if needed)
      Cc: v2.6.21+ <stable@vger.kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      b8f04bf4
    • J. Bruce Fields's avatar
      nfsd4/rpc: move backchannel create logic into rpc code · f4c24ec8
      J. Bruce Fields authored
      [ Upstream commit d50039ea ]
      
      Also simplify the logic a bit.
      
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
      Acked-by: default avatarTrond Myklebust <trondmy@primarydata.com>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      f4c24ec8
    • Lyude's avatar
      drm/i915/ilk: Don't disable SSC source if it's in use · bcb66592
      Lyude authored
      [ Upstream commit 476490a9 ]
      
      Thanks to Ville Syrjälä for pointing me towards the cause of this issue.
      
      Unfortunately one of the sideaffects of having the refclk for a DPLL set
      to SSC is that as long as it's set to SSC, the GPU will prevent us from
      powering down any of the pipes or transcoders using it. A couple of
      BIOSes enable SSC in both PCH_DREF_CONTROL and in the DPLL
      configurations. This causes issues on the first modeset, since we don't
      expect SSC to be left on and as a result, can't successfully power down
      the pipes or the transcoders using it. Here's an example from this Dell
      OptiPlex 990:
      
      [drm:intel_modeset_init] SSC enabled by BIOS, overriding VBT which says disabled
      [drm:intel_modeset_init] 2 display pipes available.
      [drm:intel_update_cdclk] Current CD clock rate: 400000 kHz
      [drm:intel_update_max_cdclk] Max CD clock rate: 400000 kHz
      [drm:intel_update_max_cdclk] Max dotclock rate: 360000 kHz
      vgaarb: device changed decodes: PCI:0000:00:02.0,olddecodes=io+mem,decodes=io+mem:owns=io+mem
      [drm:intel_crt_reset] crt adpa set to 0xf40000
      [drm:intel_dp_init_connector] Adding DP connector on port C
      [drm:intel_dp_aux_init] registering DPDDC-C bus for card0-DP-1
      [drm:ironlake_init_pch_refclk] has_panel 0 has_lvds 0 has_ck505 0
      [drm:ironlake_init_pch_refclk] Disabling SSC entirely
      … later we try committing the first modeset …
      [drm:intel_dump_pipe_config] [CRTC:26][modeset] config ffff88041b02e800 for pipe A
      [drm:intel_dump_pipe_config] cpu_transcoder: A
      …
      [drm:intel_dump_pipe_config] dpll_hw_state: dpll: 0xc4016001, dpll_md: 0x0, fp0: 0x20e08, fp1: 0x30d07
      [drm:intel_dump_pipe_config] planes on this crtc
      [drm:intel_dump_pipe_config] STANDARD PLANE:23 plane: 0.0 idx: 0 enabled
      [drm:intel_dump_pipe_config]     FB:42, fb = 800x600 format = 0x34325258
      [drm:intel_dump_pipe_config]     scaler:0 src (0, 0) 800x600 dst (0, 0) 800x600
      [drm:intel_dump_pipe_config] CURSOR PLANE:25 plane: 0.1 idx: 1 disabled, scaler_id = 0
      [drm:intel_dump_pipe_config] STANDARD PLANE:27 plane: 0.1 idx: 2 disabled, scaler_id = 0
      [drm:intel_get_shared_dpll] CRTC:26 allocated PCH DPLL A
      [drm:intel_get_shared_dpll] using PCH DPLL A for pipe A
      [drm:ilk_audio_codec_disable] Disable audio codec on port C, pipe A
      [drm:intel_disable_pipe] disabling pipe A
      ------------[ cut here ]------------
      WARNING: CPU: 1 PID: 130 at drivers/gpu/drm/i915/intel_display.c:1146 intel_disable_pipe+0x297/0x2d0 [i915]
      pipe_off wait timed out
      …
      ---[ end trace 94fc8aa03ae139e8 ]---
      [drm:intel_dp_link_down]
      [drm:ironlake_crtc_disable [i915]] *ERROR* failed to disable transcoder A
      
      Later modesets succeed since they reset the DPLL's configuration anyway,
      but this is enough to get stuck with a big fat warning in dmesg.
      
      A better solution would be to add refcounts for the SSC source, but for
      now leaving the source clock on should suffice.
      
      Changes since v4:
       - Fix calculation of final for systems with LVDS panels (fixes BUG() on
         CI test suite)
      Changes since v3:
       - Move temp variable into loop
       - Move checks for using_ssc_source to after we've figured out has_ck505
       - Add using_ssc_source to debug output
      Changes since v2:
       - Fix debug output for when we disable the CPU source
      Changes since v1:
       - Leave the SSC source clock on instead of just shutting it off on all
         of the DPLL configurations.
      
      Cc: stable@vger.kernel.org
      Reviewed-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
      Signed-off-by: default avatarLyude <cpaul@redhat.com>
      Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
      Link: http://patchwork.freedesktop.org/patch/msgid/1465916649-10228-1-git-send-email-cpaul@redhat.comSigned-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      bcb66592
    • Andrey Ryabinin's avatar
      kernel/sysrq, watchdog, sched/core: Reset watchdog on all CPUs while processing sysrq-w · 069e0fa4
      Andrey Ryabinin authored
      [ Upstream commit 57675cb9 ]
      
      Lengthy output of sysrq-w may take a lot of time on slow serial console.
      
      Currently we reset NMI-watchdog on the current CPU to avoid spurious
      lockup messages. Sometimes this doesn't work since softlockup watchdog
      might trigger on another CPU which is waiting for an IPI to proceed.
      We reset softlockup watchdogs on all CPUs, but we do this only after
      listing all tasks, and this may be too late on a busy system.
      
      So, reset watchdogs CPUs earlier, in for_each_process_thread() loop.
      Signed-off-by: default avatarAndrey Ryabinin <aryabinin@virtuozzo.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: <stable@vger.kernel.org>
      Link: http://lkml.kernel.org/r/1465474805-14641-1-git-send-email-aryabinin@virtuozzo.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      069e0fa4
    • Masami Hiramatsu's avatar
      kprobes/x86: Clear TF bit in fault on single-stepping · cd6ec94c
      Masami Hiramatsu authored
      [ Upstream commit dcfc4724 ]
      
      Fix kprobe_fault_handler() to clear the TF (trap flag) bit of
      the flags register in the case of a fault fixup on single-stepping.
      
      If we put a kprobe on the instruction which caused a
      page fault (e.g. actual mov instructions in copy_user_*),
      that fault happens on the single-stepping buffer. In this
      case, kprobes resets running instance so that the CPU can
      retry execution on the original ip address.
      
      However, current code forgets to reset the TF bit. Since this
      fault happens with TF bit set for enabling single-stepping,
      when it retries, it causes a debug exception and kprobes
      can not handle it because it already reset itself.
      
      On the most of x86-64 platform, it can be easily reproduced
      by using kprobe tracer. E.g.
      
        # cd /sys/kernel/debug/tracing
        # echo p copy_user_enhanced_fast_string+5 > kprobe_events
        # echo 1 > events/kprobes/enable
      
      And you'll see a kernel panic on do_debug(), since the debug
      trap is not handled by kprobes.
      
      To fix this problem, we just need to clear the TF bit when
      resetting running kprobe.
      Signed-off-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
      Reviewed-by: default avatarAnanth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
      Acked-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Vince Weaver <vincent.weaver@maine.edu>
      Cc: systemtap@sourceware.org
      Cc: stable@vger.kernel.org # All the way back to ancient kernels
      Link: http://lkml.kernel.org/r/20160611140648.25885.37482.stgit@devbox
      [ Updated the comments. ]
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      cd6ec94c
    • Michal Suchanek's avatar
      spi: sunxi: fix transfer timeout · 54e9cd46
      Michal Suchanek authored
      [ Upstream commit 719bd654 ]
      
      The trasfer timeout is fixed at 1000 ms. Reading a 4Mbyte flash over
      1MHz SPI bus takes way longer than that. Calculate the timeout from the
      actual time the transfer is supposed to take and multiply by 2 for good
      measure.
      Signed-off-by: default avatarMichal Suchanek <hramrach@gmail.com>
      Acked-by: default avatarMaxime Ripard <maxime.ripard@free-electrons.com>
      Signed-off-by: default avatarMark Brown <broonie@kernel.org>
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      54e9cd46
    • Marcus Weseloh's avatar
      spi: sun4i: allow transfers to set transmission speed · dadd43ff
      Marcus Weseloh authored
      [ Upstream commit 47284e3e ]
      
      Allow transfers to set the transmission speed rather than using the
      device max_speed_hz value. The SPI core makes sure that the speed_hz
      value is always set on the transfer.
      Signed-off-by: default avatarMarcus Weseloh <mweseloh42@gmail.com>
      Signed-off-by: default avatarMark Brown <broonie@kernel.org>
      Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
      dadd43ff
  2. 11 Jul, 2016 26 commits
  3. 23 Jun, 2016 1 commit
  4. 20 Jun, 2016 6 commits