1. 10 Dec, 2012 1 commit
    • Russell King - ARM Linux's avatar
      Dove: Attempt to fix PMU/RTC interrupts · 31a2aa11
      Russell King - ARM Linux authored
      commit 5d3df935 upstream.
      
      Fix the acknowledgement of PMU interrupts on Dove: some Dove hardware
      has not been sensibly designed so that interrupts can be handled in a
      race free manner.  The PMU is one such instance.
      
      The pending (aka 'cause') register is a bunch of RW bits, meaning that
      these bits can be both cleared and set by software (confirmed on the
      Armada-510 on the cubox.)
      
      Hardware sets the appropriate bit when an interrupt is asserted, and
      software is required to clear the bits which are to be processed.  If
      we write ~(1 << bit), then we end up asserting every other interrupt
      except the one we're processing.  So, we need to do a read-modify-write
      cycle to clear the asserted bit.
      
      However, any interrupts which occur in the middle of this cycle will
      also be written back as zero, which will also clear the new interrupts.
      
      The upshot of this is: there is _no_ way to safely clear down interrupts
      in this register (and other similarly behaving interrupt pending
      registers on this device.)  The patch below at least stops us creating
      new interrupts.
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      Signed-off-by: default avatarJason Cooper <jason@lakedaemon.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      31a2aa11
  2. 06 Dec, 2012 2 commits
  3. 03 Dec, 2012 37 commits