1. 06 Apr, 2007 1 commit
  2. 05 Apr, 2007 12 commits
  3. 04 Apr, 2007 21 commits
  4. 03 Apr, 2007 1 commit
    • Eric W. Biederman's avatar
      [PATCH] msi: synchronously mask and unmask msi-x irqs. · 348e3fd1
      Eric W. Biederman authored
      This is a simplified and actually more comprehensive form of a bug
      fix from Mitch Williams <mitch.a.williams@intel.com>.
      When we mask or unmask a msi-x irqs the writes may be posted because
      we are writing to memory mapped region.  This means the mask and
      unmask don't happen immediately but at some unspecified time in the
      future.  Which is out of sync with how the mask/unmask logic work
      for ioapic irqs.
      The practical result is that we get very subtle and hard to track down
      irq migration bugs.
      This patch performs a read flush after writes to the MSI-X table for mask
      and unmask operations.  Since the SMP affinity is set while the interrupt
      is masked, and since it's unmasked immediately after, no additional flushes
      are required in the various affinity setting routines.
      The testing by Mitch Williams on his especially problematic system should
      still be valid as I have only simplified the code, not changed the
      We currently have 7 drivers: cciss, mthca, cxgb3, forceth, s2io,
      pcie/portdrv_core, and qla2xxx in 2.6.21 that are affected by this
      problem when the hardware they driver is plugged into the right slot.
      Given the difficulty of reproducing this bug and tracing it down to
      anything that even remotely resembles a cause, even if people are
      being affected we aren't likely to see many meaningful bug reports, and
      the people who see this bug aren't likely to be able to reproduce this
      bug in a timely fashion.  So it is best to get this problem fixed
      as soon as we can so people don't have problems.
      Then if people do have a kernel message stating "No irq for vector" we
      will know it is yet another novel cause that needs a complete new
      Cc: Greg KH <greg@kroah.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
      Acked-by: default avatarMitch Williams <mitch.a.williams@intel.com>
      Acked-by: default avatar"Siddha, Suresh B" <suresh.b.siddha@intel.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
  5. 02 Apr, 2007 5 commits