recipes/linux/linux-rp-2.6.24/pxa27x-resume.patch

   1 List:       linux-arm-kernel
   2 Subject:    [PATCH] Fix PXA27x resume
   3 From:       Russell King - ARM Linux <linux@arm.linux.org.uk>
   4 Date:       2008-01-21 13:53:31
   5 Message-ID: 20080121135331.GC30149@flint.arm.linux.org.uk
   6 [Download message RAW]
   7
   8 When PXA27x wakes up, tick_resume_oneshot() tries to set a timer
   9 interrupt to occur immediately.  Since PXA27x requires at least
  10 MIN_OSCR_DELTA, this causes us to flag an error.
  11
  12 tick_program_event() then increments the next event time by
  13 min_delta_ns.  However, by the time we get back to programming
  14 the next event, the OSCR has incremented such that we fail again.
  15 We repeatedly retry, but the OSCR is too fast for us - we never
  16 catch up, so we never break out of the loop - resulting in us
  17 never apparantly resuming.
  18
  19 Fix this by doubling min_delta_ns.
  20
  21 Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
  22
  23 diff --git a/arch/arm/mach-pxa/time.c b/arch/arm/mach-pxa/time.c
  24 index ac0bbad..7b7c017 100644
  25 --- a/arch/arm/mach-pxa/time.c
  26 +++ b/arch/arm/mach-pxa/time.c
  27 @@ -169,7 +169,7 @@ static void __init pxa_timer_init(void)
  28         ckevt_pxa_osmr0.max_delta_ns =
  29                 clockevent_delta2ns(0x7fffffff, &ckevt_pxa_osmr0);
  30         ckevt_pxa_osmr0.min_delta_ns =
  31 -               clockevent_delta2ns(MIN_OSCR_DELTA, &ckevt_pxa_osmr0) + 1;
  32 +               clockevent_delta2ns(MIN_OSCR_DELTA * 2, &ckevt_pxa_osmr0) + 1;
  33
  34         cksrc_pxa_oscr0.mult =
  35                 clocksource_hz2mult(clock_tick_rate, cksrc_pxa_oscr0.shift);
  36
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