1. 11 May, 2008 15 commits
    • David Brownell's avatar
      i2c: Improve smbus-protocol documentation · 1a31a88f
      David Brownell authored
      Improve the smbus-protocol documentation file somewhat:
      
       - Use the names of the SMBus protocol operations (from the 2.0
         specification), not made-up-for-Linux names.
      
       - Add the name of the call used to execute each operation ... and
         point out that there are mismatches, where functions execute
         different protocol operations than their names specify.
         
      The most confusing examples are that "Read Byte" isn't executed by
      i2c_smbus_read_byte(), and that "Write Byte" isn't executed by
      i2c_smbus_write_byte().  When coding, that's not as bad as it may
      seem; but that case would seem to be worth fixing.
      Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
      Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
      1a31a88f
    • Jean Delvare's avatar
      i2c-piix4: Blacklist two mainboards · c2fc54fc
      Jean Delvare authored
      We had a report that running sensors-detect on a Sapphire AM2RD790
      motherbord killed the CPU. While the exact cause is still unknown,
      I'd rather play it safe and prevent any access to the SMBus on that
      machine by not letting the i2c-piix4 driver attach to the SMBus host
      device on that machine. Also blacklist a similar board made by DFI.
      Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
      c2fc54fc
    • David Milburn's avatar
      i2c-piix4: Increase the intitial delay for the ServerWorks CSB5 · b1c1759c
      David Milburn authored
      Per the PIIX4 errata, there maybe a delay between setting the
      start bit in the Smbus Host Controller Register and the transaction
      actually starting. If the driver doesn't delay long enough, it
      may appear that the transaction is complete when actually it
      hasn't started, this may lead to bus collisions.
      
      While 1 ms appears to be enough for most chips, the ServerWorks CSB5
      wants 2 ms.
      Signed-off-by: default avatarDavid Milburn <dmilburn@redhat.com>
      Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
      b1c1759c
    • Jon Smirl's avatar
      i2c-mpc: Compare to NO_IRQ instead of zero · f5fff360
      Jon Smirl authored
      Alter the mpc i2c driver to use the NO_IRQ symbol instead of the constant
      zero when checking for valid interrupts. NO_IRQ=-1 on ppc and NO_IRQ=0 on
      powerpc so the checks against zero are not correct.
      Signed-off-by: default avatarJon Smirl <jonsmirl@gmail.com>
      Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
      f5fff360
    • Bernhard Beck's avatar
      usb-serial: Add ThinkOptics WavIT · 96623697
      Bernhard Beck authored
      Add ThinkOptics WavIt to cp2101 device table
      Signed-off-by: default avatarBernhard Beck <kernel@goodcoffee.net>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      96623697
    • Linus Torvalds's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6 · 854a9895
      Linus Torvalds authored
      * git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6:
        sparc: Fix debugger syscall restart interactions.
        sparc: Fix ptrace() detach.
        sparc32: Don't twiddle PT_DTRACE in exec.
        sparc video: remove open boot prom code
      854a9895
    • Linus Torvalds's avatar
      633331f3
    • David S. Miller's avatar
      sparc: Fix debugger syscall restart interactions. · 28e61036
      David S. Miller authored
      So, forever, we've had this ptrace_signal_deliver implementation
      which tries to handle all of the nasties that can occur when the
      debugger looks at a process about to take a signal.  It's meant
      to address all of these issues inside of the kernel so that the
      debugger need not be mindful of such things.
      
      Problem is, this doesn't work.
      
      The idea was that we should do the syscall restart business first, so
      that the debugger captures that state.  Otherwise, if the debugger for
      example saves the child's state, makes the child execute something
      else, then restores the saved state, we won't handle the syscall
      restart properly because we lose the "we're in a syscall" state.
      
      The code here worked for most cases, but if the debugger actually
      passes the signal through to the child unaltered, it's possible that
      we would do a syscall restart when we shouldn't have.
      
      In particular this breaks the case of debugging a process under a gdb
      which is being debugged by yet another gdb.  gdb uses sigsuspend
      to wait for SIGCHLD of the inferior, but if gdb itself is being
      debugged by a top-level gdb we get a ptrace_stop().  The top-level gdb
      does a PTRACE_CONT with SIGCHLD to let the inferior gdb see the
      signal.  But ptrace_signal_deliver() assumed the debugger would cancel
      out the signal and therefore did a syscall restart, because the return
      error was ERESTARTNOHAND.
      
      Fix this by simply making ptrace_signal_deliver() a nop, and providing
      a way for the debugger to control system call restarting properly:
      
      1) Report a "in syscall" software bit in regs->{tstate,psr}.
         It is set early on in trap entry to a system call and is fully
         visible to the debugger via ptrace() and regsets.
      
      2) Test this bit right before doing a syscall restart.  We have
         to do a final recheck right after get_signal_to_deliver() in
         case the debugger cleared the bit during ptrace_stop().
      
      3) Clear the bit in trap return so we don't accidently try to set
         that bit in the real register.
      
      As a result we also get a ptrace_{is,clear}_syscall() for sparc32 just
      like sparc64 has.
      
      M68K has this same exact bug, and is now the only other user of the
      ptrace_signal_deliver hook.  It needs to be fixed in the same exact
      way as sparc.
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      28e61036
    • David S. Miller's avatar
      sparc: Fix ptrace() detach. · 986bef85
      David S. Miller authored
      Forever we had a PTRACE_SUNOS_DETACH which was unconditionally
      recognized, regardless of the personality of the process.
      
      Unfortunately, this value is what ended up in the GLIBC sys/ptrace.h
      header file on sparc as PTRACE_DETACH and PT_DETACH.
      
      So continue to recognize this old value.  Luckily, it doesn't conflict
      with anything we actually care about.
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      986bef85
    • Linus Torvalds's avatar
      Merge master.kernel.org:/home/rmk/linux-2.6-arm · 5bb7ff79
      Linus Torvalds authored
      * master.kernel.org:/home/rmk/linux-2.6-arm:
        [ARM] 5033/1: Unbreak corgi_ssp by registering ssp drivers earlier.
        [ARM] Orion: clean up addr-map.c after window setting code purge
        [ARM] Orion: pass proper t_clk into mv643xx_eth
        [ARM] Orion: use mv643xx_eth driver mbus window handling
        [ARM] pxa: Fix RCSR handling
        [ARM] lubbock: fix compilation
        [ARM] 5032/1: Added cpufreq support for pxa27x CPU
        [ARM] 5031/1: Indentation correction in cpu-pxa.c.
        [ARM] 5028/1: pxafb: fix broken "backward compatibility way" in framebuffer
        [ARM] 4882/2: Correction for S3C2410 clkout generation
        [ARM] 5027/1: Fixed random memory corruption on pxa suspend cycle.
        [ARM] 5024/1: Fix some minor clk issues in the MMCI PL18x driver
        [ARM] 5023/1: Fix broken gpio interrupts on ep93xx
        ns9xxx: fix sparse warning
        ns9xxx: check for irq lockups
        ns9xxx: fix handle_prio_irq to unmask irqs with lower priority
      5bb7ff79
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86 · 3e1b83ab
      Linus Torvalds authored
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86:
        x86: rdc: leds build/config fix
        x86: sysfs cpu?/topology is empty in 2.6.25 (32-bit Intel system)
        x86: revert commit 709f744f ("x86: bitops asm constraint fixes")
        x86: restrict keyboard io ports reservation to make ipmi driver work
        x86: fix fpu restore from sig return
        x86: remove spew print out about bus to node mapping
        x86: revert printk format warning change which is for linux-next
        x86: cleanup PAT cpu validation
        x86: geode: define geode_has_vsa2() even if CONFIG_MGEODE_LX is not set
        x86: GEODE: cache results from geode_has_vsa2() and uninline
        x86: revert geode config dependency
      3e1b83ab
    • Linus Torvalds's avatar
      BKL: revert back to the old spinlock implementation · 8e3e076c
      Linus Torvalds authored
      The generic semaphore rewrite had a huge performance regression on AIM7
      (and potentially other BKL-heavy benchmarks) because the generic
      semaphores had been rewritten to be simple to understand and fair.  The
      latter, in particular, turns a semaphore-based BKL implementation into a
      mess of scheduling.
      
      The attempt to fix the performance regression failed miserably (see the
      previous commit 00b41ec2 'Revert
      "semaphore: fix"'), and so for now the simple and sane approach is to
      instead just go back to the old spinlock-based BKL implementation that
      never had any issues like this.
      
      This patch also has the advantage of being reported to fix the
      regression completely according to Yanmin Zhang, unlike the semaphore
      hack which still left a couple percentage point regression.
      
      As a spinlock, the BKL obviously has the potential to be a latency
      issue, but it's not really any different from any other spinlock in that
      respect.  We do want to get rid of the BKL asap, but that has been the
      plan for several years.
      
      These days, the biggest users are in the tty layer (open/release in
      particular) and Alan holds out some hope:
      
        "tty release is probably a few months away from getting cured - I'm
         afraid it will almost certainly be the very last user of the BKL in
         tty to get fixed as it depends on everything else being sanely locked."
      
      so while we're not there yet, we do have a plan of action.
      Tested-by: default avatarYanmin Zhang <yanmin_zhang@linux.intel.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: Matthew Wilcox <matthew@wil.cx>
      Cc: Alexander Viro <viro@ftp.linux.org.uk>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      8e3e076c
    • Linus Torvalds's avatar
      Revert "semaphore: fix" · 00b41ec2
      Linus Torvalds authored
      This reverts commit bf726eab, as it has
      been reported to cause a regression with processes stuck in __down(),
      apparently because some missing wakeup.
      
      Quoth Sven Wegener:
       "I'm currently investigating a regression that has showed up with my
        last git pull yesterday.  Bisecting the commits showed bf726e
        "semaphore: fix" to be the culprit, reverting it fixed the issue.
      
        Symptoms: During heavy filesystem usage (e.g.  a kernel compile) I get
        several compiler processes in uninterruptible sleep, blocking all i/o
        on the filesystem.  System is an Intel Core 2 Quad running a 64bit
        kernel and userspace.  Filesystem is xfs on top of lvm.  See below for
        the output of sysrq-w."
      
      See
      
      	http://lkml.org/lkml/2008/5/10/45
      
      for full report.
      
      In the meantime, we can just fix the BKL performance regression by
      reverting back to the good old BKL spinlock implementation instead,
      since any sleeping lock will generally perform badly, especially if it
      tries to be fair.
      Reported-by: default avatarSven Wegener <sven.wegener@stealer.net>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Ingo Molnar <mingo@elte.hu>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      00b41ec2
    • Linus Torvalds's avatar
      Make <asm-x86/spinlock.h> use ACCESS_ONCE() · 39f004ba
      Linus Torvalds authored
      ..instead of cooking up its own uglier local version of it.
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      39f004ba
    • Linus Torvalds's avatar
      Move ACCESS_ONCE() to <linux/compiler.h> · 9c3cdc1f
      Linus Torvalds authored
      It actually makes much more sense there, and we do tend to need it for
      non-RCU usage too.  Moving it to <linux/compiler.h> will allow some
      other cases that have open-coded the same logic to use the same helper
      function that RCU has used.
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9c3cdc1f
  2. 10 May, 2008 8 commits
  3. 09 May, 2008 17 commits