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  1. 09 Jan, 2008 7 commits
  3. 08 Jan, 2008 5 commits
  5. 07 Jan, 2008 11 commits
  7. 06 Jan, 2008 7 commits
    • Linus Torvalds's avatar
      Merge master.kernel.org:/home/rmk/linux-2.6-arm · 2b300d20
      Linus Torvalds authored 
      * master.kernel.org:/home/rmk/linux-2.6-arm:
  [ARM] 4691/1: add missing i2c_board_info struct for at91rm9200
  [ARM] 4735/1: Unbreak pxa25x suspend/resume
      2b300d20
    • Linus Torvalds's avatar
      Linux 2.6.24-rc7 · 3ce54450
      Linus Torvalds authored
      3ce54450
    • Ingo Molnar's avatar
      CPU hotplug: fix cpu_is_offline() on !CONFIG_HOTPLUG_CPU · a263898f
      Ingo Molnar authored 
      make randconfig bootup testing found that the cpufreq code
crashes on bootup, if the powernow-k8 driver is enabled and
if maxcpus=1 passed on the boot line to a !CONFIG_HOTPLUG_CPU
kernel.

First lockdep found out that there's an inconsistent unlock
sequence:

 =====================================
 [ BUG: bad unlock balance detected! ]
 -------------------------------------
 swapper/1 is trying to release lock (&per_cpu(cpu_policy_rwsem, cpu)) at:
 [<ffffffff806ffd8e>] unlock_policy_rwsem_write+0x3c/0x42
 but there are no more locks to release!

Call Trace:
 [<ffffffff806ffd8e>] unlock_policy_rwsem_write+0x3c/0x42
 [<ffffffff80251c29>] print_unlock_inbalance_bug+0x104/0x12c
 [<ffffffff80252f3a>] mark_held_locks+0x56/0x94
 [<ffffffff806ffd8e>] unlock_policy_rwsem_write+0x3c/0x42
 [<ffffffff807008b6>] cpufreq_add_dev+0x2a8/0x5c4
 ...

then shortly afterwards the cpufreq code crashed on an assert:

 ------------[ cut here ]------------
 kernel BUG at drivers/cpufreq/cpufreq.c:1068!
 invalid opcode: 0000 [1] SMP
 [...]
 Call Trace:
  [<ffffffff805145d6>] sysdev_driver_unregister+0x5b/0x91
  [<ffffffff806ff520>] cpufreq_register_driver+0x15d/0x1a2
  [<ffffffff80cc0596>] powernowk8_init+0x86/0x94
 [...]
 ---[ end trace 1e9219be2b4431de ]---

the bug was caused by maxcpus=1 bootup, which brought up the
secondary core as !cpu_online() but !cpu_is_offline() either,
which on on !CONFIG_HOTPLUG_CPU is always 0 (include/linux/cpu.h):

  /* CPUs don't go offline once they're online w/o CONFIG_HOTPLUG_CPU */
  static inline int cpu_is_offline(int cpu) { return 0; }

but the cpufreq code uses cpu_online() and cpu_is_offline() in
a mixed way - the low-level drivers use cpu_online(), while
the cpufreq core uses cpu_is_offline(). This opened up the
possibility to add the non-initialized sysdev device of the
secondary core:

 cpufreq-core: trying to register driver powernow-k8
 cpufreq-core: adding CPU 0
 powernow-k8: BIOS error - no PSB or ACPI _PSS objects
 cpufreq-core: initialization failed
 cpufreq-core: adding CPU 1
 cpufreq-core: initialization failed

which then blew up. The fix is to make cpu_is_offline() always
the negation of cpu_online(). With that fix applied the kernel
boots up fine without crashing:

 Calling initcall 0xffffffff80cc0510: powernowk8_init+0x0/0x94()
 powernow-k8: Found 1 AMD Athlon(tm) 64 X2 Dual Core Processor 3800+ processors (1 cpu cores) (version 2.20.00)
 powernow-k8: BIOS error - no PSB or ACPI _PSS objects
 initcall 0xffffffff80cc0510: powernowk8_init+0x0/0x94() returned -19.
 initcall 0xffffffff80cc0510 ran for 19 msecs: powernowk8_init+0x0/0x94()
 Calling initcall 0xffffffff80cc328f: init_lapic_nmi_sysfs+0x0/0x39()

We could fix this by making CPU enumeration aware of max_cpus, but that
would be more fragile IMO, and the cpu_online(cpu) != cpu_is_offline(cpu)
possibility was quite confusing and a continuous source of bugs too.

Most distributions have kernels with CPU hotplug enabled, so this bug
remained hidden for a long time.

Bug forensics:

The broken cpu_is_offline() API variant was introduced via:

 commit a59d2e4e6977e7b94e003c96a41f07e96cddc340
 Author: Rusty Russell <rusty@rustcorp.com.au>
 Date:   Mon Mar 8 06:06:03 2004 -0800

     [PATCH] minor cleanups for hotplug CPUs

( this predates linux-2.6.git, this commit is available from Thomas's
  historic git tree. )

Then 1.5 years later the cpufreq code made use of it:

 commit c32b6b8e
 Author: Ashok Raj <ashok.raj@intel.com>
 Date:   Sun Oct 30 14:59:54 2005 -0800

     [PATCH] create and destroy cpufreq sysfs entries based on cpu notifiers

 +       if (cpu_is_offline(cpu))
 +               return 0;

which is a correct use of the subtly broken new API. v2.6.15 then
shipped with this bug included.

then it took two more years for random-kernel qa to hit it.
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a263898f
    • Ingo Molnar's avatar
      hda_intel suspend latency: shorten codec read · 57a04513
      Ingo Molnar authored 
      not sleeping for every codec read/write but doing a short udelay and
a conditional reschedule has cut suspend+resume latency by about 1
second on my T60.

The patch also fixes the unexpected codec-connection errors that
happen more often in the new power-save mode:
    http://lkml.org/lkml/2007/11/8/255
    http://bugzilla.kernel.org/show_bug.cgi?id=9332Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Acked-by: default avatarTakashi Iwai <tiwai@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      57a04513
    • Jan Altenberg's avatar
      [ARM] 4691/1: add missing i2c_board_info struct for at91rm9200 · 430cb436
      Jan Altenberg authored 
      - Add missing i2c_board_info struct for at91rm9200
Signed-off-by: default avatarJan Altenberg <jan.altenberg@linutronix.de>
Acked-by: default avatarAndrew Victor <avictor.za@gmail.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      430cb436
    • Akos Maroy's avatar
      fix: using joysticks in 32 bit applications on 64 bit systems · 3fee37c1
      Akos Maroy authored 
      unfortunately 32 bit apps don't see the joysticks on a 64 bit system.
this prevents one playing X-Plane (http://www.x-plane.com/) or other
32-bit games with joysticks.

this is a known issue, and already raised several times:

 http://readlist.com/lists/vger.kernel.org/linux-kernel/28/144411.html

 http://www.brettcsmith.org/wiki/wiki.cgi?action=browse&diff=1&id=OzyComputer/Joystick

unfortunately this is still not fixed in the mainline kernel.

it would be nice to have this fixed, so that people can play these games
without having to patch their kernel.

the following patch solves the problem on 2.6.22.
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarChristoph Hellwig <hch@infradead.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      3fee37c1
    • Linus Torvalds's avatar
      Revert "scsi: revert "[SCSI] Get rid of scsi_cmnd->done"" · 7b3d9545
      Linus Torvalds authored 
      This reverts commit ac40532e, which gets
us back the original cleanup of 6f5391c2.

It turns out that the bug that was triggered by that commit was
apparently not actually triggered by that commit at all, and just the
testing conditions had changed enough to make it appear to be due to it.

The real problem seems to have been found by Peter Osterlund:

  "pktcdvd sets it [block device size] when opening the /dev/pktcdvd
   device, but when the drive is later opened as /dev/scd0, there is
   nothing that sets it back.  (Btw, 40944 is possible if the disk is a
   CDRW that was formatted with "cdrwtool -m 10236".)

   The problem is that pktcdvd opens the cd device in non-blocking mode
   when pktsetup is run, and doesn't close it again until pktsetup -d is
   run.  The effect is that if you meanwhile open the cd device,
   blkdev.c:do_open() doesn't call bd_set_size() because
   bdev->bd_openers is non-zero."

In particular, to repeat the bug (regardless of whether commit
6f5391c2 is applied or not):

  " 1. Start with an empty drive.
    2. pktsetup 0 /dev/scd0
    3. Insert a CD containing an isofs filesystem.
    4. mount /dev/pktcdvd/0 /mnt/tmp
    5. umount /mnt/tmp
    6. Press the eject button.
    7. Insert a DVD containing a non-writable filesystem.
    8. mount /dev/scd0 /mnt/tmp
    9. find /mnt/tmp -type f -print0 | xargs -0 sha1sum >/dev/null
    10. If the DVD contains data beyond the physical size of a CD, you
        get I/O errors in the terminal, and dmesg reports lots of
        "attempt to access beyond end of device" errors."

which in turn is because the nested open after the media change won't
cause the size to be set properly (because the original open still holds
the block device, and we only do the bd_set_size() when we don't have
other people holding the device open).

The proper fix for that is probably to just do something like

	bdev->bd_inode->i_size = (loff_t)get_capacity(disk)<<9;

in fs/block_dev.c:do_open() even for the cases where we're not the
original opener (but *not* call bd_set_size(), since that will also
change the block size of the device).

Cc: Peter Osterlund <petero2@telia.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      7b3d9545
  9. 04 Jan, 2008 10 commits