1. 06 Apr, 2012 5 commits
    • Alan Stern's avatar
      USB documentation: explain lifetime rules for unlinking URBs · da8bfb09
      Alan Stern authored
      This patch (as1534c) updates the documentation for usb_unlink_urb and
      related functions.  It explains that the caller must prevent the URB
      being unlinked from getting deallocated while the unlink is taking
      place.
      Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
      CC: Ming Lei <tom.leiming@gmail.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      da8bfb09
    • Alan Stern's avatar
      USB: don't clear urb->dev in scatter-gather library · bcf39853
      Alan Stern authored
      This patch (as1517b) fixes an error in the USB scatter-gather library.
      The library code uses urb->dev to determine whether or nor an URB is
      currently active; the completion handler sets urb->dev to NULL.
      However the core unlinking routines need to use urb->dev.  Since
      unlinking always racing with completion, the completion handler must
      not clear urb->dev -- it can lead to invalid memory accesses when a
      transfer has to be cancelled.
      
      This patch fixes the problem by getting rid of the lines that clear
      urb->dev after urb has been submitted.  As a result we may end up
      trying to unlink an URB that failed in submission or that has already
      completed, so an extra check is added after each unlink to avoid
      printing an error message when this happens.  The checks are updated
      in both sg_complete() and sg_cancel(), and the second is updated to
      match the first (currently it prints out unnecessary warning messages
      if a device is unplugged while a transfer is in progress).
      Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
      Reported-and-tested-by: default avatarIllia Zaitsev <I.Zaitsev@adbglobal.com>
      CC: Ming Lei <tom.leiming@gmail.com>
      CC: <stable@vger.kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      bcf39853
    • Ming Lei's avatar
      usb: storage: fix lockdep warning inside usb_stor_pre_reset(v2) · c825bab0
      Ming Lei authored
      This patch fixes one lockdep warning[1] inside usb_stor_pre_reset.
      
      If the current configuration includes multiple mass storage interfaces,
      the 'AA' lockdep warning will be triggered since the lock class of
      'us->dev_mutex' is acquired two times in .reset path. It isn't
      a real deadlock, so just take the lockdep_set_class annotation to
      remove the warning.
      
      [1], lockdep warning log
      :[ INFO: possible recursive locking detected ]
      :3.3.0-0.rc5.git3.1.fc17.x86_64 #1 Tainted: G        W
      :---------------------------------------------
      :usb-storage/14846 is trying to acquire lock:
      : (&(us->dev_mutex)){+.+.+.}, at: [<ffffffffa0481c0c>] usb_stor_pre_reset+0x1c/0x20 [usb_storage]
      :but task is already holding lock:
      : (&(us->dev_mutex)){+.+.+.}, at: [<ffffffffa0481c0c>] usb_stor_pre_reset+0x1c/0x20 [usb_storage]
      :other info that might help us debug this:
      : Possible unsafe locking scenario:
      :       CPU0
      :       ----
      :  lock(&(us->dev_mutex));
      :  lock(&(us->dev_mutex));
      : *** DEADLOCK ***
      : May be due to missing lock nesting notation
      :2 locks held by usb-storage/14846:
      : #0:  (&__lockdep_no_validate__){......}, at: [<ffffffff8147e6a5>] usb_lock_device_for_reset+0x95/0x100
      : #1:  (&(us->dev_mutex)){+.+.+.}, at: [<ffffffffa0481c0c>] usb_stor_pre_reset+0x1c/0x20 [usb_storage]
      :stack backtrace:
      :Pid: 14846, comm: usb-storage Tainted: G        W 3.3.0-0.rc5.git3.1.fc17.x86_64 #1
      :Call Trace:
      : [<ffffffff810cbdaf>] __lock_acquire+0x168f/0x1bb0
      : [<ffffffff81021083>] ? native_sched_clock+0x13/0x80
      : [<ffffffff810210f9>] ? sched_clock+0x9/0x10
      : [<ffffffff810210f9>] ? sched_clock+0x9/0x10
      : [<ffffffff810a2975>] ? sched_clock_local+0x25/0xa0
      : [<ffffffff810cc9a1>] lock_acquire+0xa1/0x1e0
      : [<ffffffffa0481c0c>] ? usb_stor_pre_reset+0x1c/0x20 [usb_storage]
      : [<ffffffff81699c86>] mutex_lock_nested+0x76/0x3a0
      : [<ffffffffa0481c0c>] ? usb_stor_pre_reset+0x1c/0x20 [usb_storage]
      : [<ffffffffa0481c0c>] ? usb_stor_pre_reset+0x1c/0x20 [usb_storage]
      : [<ffffffffa0481c0c>] usb_stor_pre_reset+0x1c/0x20 [usb_storage]
      : [<ffffffff8148184d>] usb_reset_device+0x7d/0x190
      : [<ffffffffa048119c>] usb_stor_port_reset+0x7c/0x80 [usb_storage]
      : [<ffffffffa0481234>] usb_stor_invoke_transport+0x94/0x560 [usb_storage]
      : [<ffffffff810cd3b2>] ? mark_held_locks+0xb2/0x130
      : [<ffffffff8169dbd0>] ? _raw_spin_unlock_irq+0x30/0x50
      : [<ffffffffa047fe3e>] usb_stor_transparent_scsi_command+0xe/0x10 [usb_storage]
      : [<ffffffffa0481ae3>] usb_stor_control_thread+0x173/0x280 [usb_storage]
      : [<ffffffffa0481970>] ? fill_inquiry_response+0x20/0x20 [usb_storage]
      : [<ffffffff8108a3f7>] kthread+0xb7/0xc0
      : [<ffffffff816a7d34>] kernel_thread_helper+0x4/0x10
      : [<ffffffff8169e0f4>] ? retint_restore_args+0x13/0x13
      : [<ffffffff8108a340>] ? kthread_worker_fn+0x1a0/0x1a0
      : [<ffffffff816a7d30>] ? gs_change+0x13/0x13
      Reported-By: default avatarDave Jones <davej@redhat.com>
      Signed-off-by: default avatarMing Lei <tom.leiming@gmail.com>
      Acked-by: default avatarAlan Stern <stern@rowland.harvard.edu>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      c825bab0
    • Sebastian Andrzej Siewior's avatar
      usb/usbmon: correct the data interpretation of usbmon's output · 2e8dc2f2
      Sebastian Andrzej Siewior authored
      The doc says that the data
      | 55534243 5e000000 00000000 00000600 00000000 00000000 00000000 000000
      is the SCSI command 0x5e. According to the usbmon source, it dumps one
      byte after the other. The first 4 bytes are US_BULK_CB_SIGN which is
      correct. After that we see the TAG which is 0x5e. The cdb is 0x00 in
      this example.
      In order to correct this, I change the example to a READ_10 command
      which is 0x28 so it is not just a zero somewhere in the stream.
      Signed-off-by: default avatarSebastian Andrzej Siewior <sebastian@breakpoint.cc>
      Acked-by: default avatarAlan Stern <stern@rowland.harvard.edu>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      2e8dc2f2
    • David Daney's avatar
      usb: Put USB Kconfig items back under USB. · a8edc42a
      David Daney authored
      commit 53c6bc24 (usb: Don't make
      USB_ARCH_HAS_{XHCI,OHCI,EHCI} depend on USB_SUPPORT.)  Removed the
      dependency of the USB_ARCH_HAS_* symbols on USB_SUPPORT.  However the
      resulting Kconfig somehow caused many of the USB configuration items
      to appear under the top level devices menu.
      
      To fix this we reunite the 'menuconfig USB_SUPPORT' with the 'if
      USB_SUPPORT', and the config items magically go back to their desired
      location.
      Reported-by: default avatarJulian Wollrath <jwollrath@web.de>
      Reported-by: default avatarNobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
      Reported-by: default avatarBorislav Petkov <bp@alien8.de>
      Reported-by: default avatarRupesh Gujare <rgujare@ozmodevices.com>
      Reported-by: default avatarFeng King <ronyjin@tencent.com>
      Reported-by: default avatarJean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
      Signed-off-by: default avatarDavid Daney <david.daney@cavium.com>
      Tested-by: default avatarPeter Chen <peter.chen@freescale.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      a8edc42a
  2. 31 Mar, 2012 35 commits