[lkml]   [2011]   [Dec]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    Jens Rottmann schrieb:
    > Andres Salomon schrieb:
    >> Just loading cs5535-clockevt should start the periodic timer.
    >> On my XO-1, IRQ 7 starts firing immediately.
    > Hmm, no, doesn't work. :-| In /proc/interrupts IRQ 0 gets increased,
    > not (in my case) IRQ 11.

    Update: I found that SMP-enabled kernels (like the generic one I was using) do
    load cs5535-clockevt fine but ignore it and keep using the pit timer instead.

    Responsible seems kernel/time/tick-common.c: tick_check_new_device()
    * If the cpu affinity of the device interrupt can not
    * be set, ignore it.
    if (!irq_can_set_affinity(newdev->irq))
    goto out_bc;

    Looks like it has been that way for quite some time, maybe cs5535-clockevt
    hasn't ever worked on SMP kernels.

    If I turn off SMP, cs5535-clockevt replaces the pit timer and the MFGPT IRQ
    starts firing just as you said - at least on 3.0.9. 3.2-rc5 prefers to hang
    instead, looks like no timer events get generated. Sigh.

    I'll try to narrow it down tomorrow, but now I'm calling it a day.


     \ /
      Last update: 2011-12-14 19:41    [W:0.018 / U:12.048 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site