1. 05 10月, 2006 1 次提交
    • D
      IRQ: Maintain regs pointer globally rather than passing to IRQ handlers · 7d12e780
      David Howells 提交于
      Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
      of passing regs around manually through all ~1800 interrupt handlers in the
      Linux kernel.
      
      The regs pointer is used in few places, but it potentially costs both stack
      space and code to pass it around.  On the FRV arch, removing the regs parameter
      from all the genirq function results in a 20% speed up of the IRQ exit path
      (ie: from leaving timer_interrupt() to leaving do_IRQ()).
      
      Where appropriate, an arch may override the generic storage facility and do
      something different with the variable.  On FRV, for instance, the address is
      maintained in GR28 at all times inside the kernel as part of general exception
      handling.
      
      Having looked over the code, it appears that the parameter may be handed down
      through up to twenty or so layers of functions.  Consider a USB character
      device attached to a USB hub, attached to a USB controller that posts its
      interrupts through a cascaded auxiliary interrupt controller.  A character
      device driver may want to pass regs to the sysrq handler through the input
      layer which adds another few layers of parameter passing.
      
      I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
      main part of the code on FRV and i386, though I can't test most of the drivers.
      I've also done partial conversion for powerpc and MIPS - these at least compile
      with minimal configurations.
      
      This will affect all archs.  Mostly the changes should be relatively easy.
      Take do_IRQ(), store the regs pointer at the beginning, saving the old one:
      
      	struct pt_regs *old_regs = set_irq_regs(regs);
      
      And put the old one back at the end:
      
      	set_irq_regs(old_regs);
      
      Don't pass regs through to generic_handle_irq() or __do_IRQ().
      
      In timer_interrupt(), this sort of change will be necessary:
      
      	-	update_process_times(user_mode(regs));
      	-	profile_tick(CPU_PROFILING, regs);
      	+	update_process_times(user_mode(get_irq_regs()));
      	+	profile_tick(CPU_PROFILING);
      
      I'd like to move update_process_times()'s use of get_irq_regs() into itself,
      except that i386, alone of the archs, uses something other than user_mode().
      
      Some notes on the interrupt handling in the drivers:
      
       (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
           the input_dev struct.
      
       (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
           something different depending on whether it's been supplied with a regs
           pointer or not.
      
       (*) Various IRQ handler function pointers have been moved to type
           irq_handler_t.
      Signed-Off-By: NDavid Howells <dhowells@redhat.com>
      (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
      7d12e780
  2. 04 10月, 2006 1 次提交
  3. 29 9月, 2006 1 次提交
  4. 28 9月, 2006 10 次提交
  5. 08 9月, 2006 1 次提交
  6. 27 8月, 2006 1 次提交
  7. 12 8月, 2006 1 次提交
  8. 03 8月, 2006 1 次提交
  9. 13 7月, 2006 2 次提交
  10. 01 7月, 2006 1 次提交
  11. 22 6月, 2006 7 次提交
  12. 13 5月, 2006 1 次提交
    • M
      [PATCH] USB: Emagic USB firmware loading fixes · 16c23f7d
      Monty 提交于
      It's become apparent as machines get faster that the emagic kernel firmware
      loaders (based on the ezusb loader) have a reset race.  a 400MHz TiBook
      never tripped it, but a 2GHz Pentium M seems to hit it about 30% of the
      time.  The bug is seen as a hung USB box and the kernel error:
      
      drivers/usb/misc/emi62.c: emi62_load_firmware - error loading firmware:
      error = -110
      
      The patch below inserts a delay after deasserting reset to allow the box to
      settle before a new command is issued.  This affects only device startup.
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      16c23f7d
  13. 15 4月, 2006 1 次提交
    • D
      [PATCH] USB: usbtest: scatterlist OUT data pattern testing · 8b524901
      David Brownell 提交于
      Previously, scatterlist tests didn't write patterned data.  Given how many
      corner cases are addresed by them, this was a significant gap in Linux-USB
      test coverage.  Moreover, when peripherals checked for correct data patterns,
      false error reports would drown out the true ones.
      
      This adds the pattern on the way OUT from the host, so scatterlist tests can
      now be used to uncover bugs like host TX or peripheral RX paths failing for
      back-to-back short packets.  It's easy enough to get an error there with at
      least one of the {DMA,PIO}{RX,TX} code paths, or run into hardware races
      that need to be defended against.
      
      Note this patch doesn't add checking for correct data patterns on the way
      IN from peripherals, just a FIXME for later.
      Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      8b524901
  14. 21 3月, 2006 10 次提交
  15. 14 2月, 2006 1 次提交