lkml.org 
[lkml]   [2007]   [Nov]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH PREEMPT_RT]: On AT91 ARM: GPIO Interrupt handling can/will stall forever
    On Wed, Nov 28, 2007 at 04:13:07PM -0500, Steven Rostedt wrote:
    >
    >
    > On Wed, 28 Nov 2007, Daniel Walker wrote:
    >
    > >
    > > Ignoring the ARM side of things for a sec, handle_simple_irq() will
    > > mask() the interrupt in the special case that an interrupt is already in
    > > the processes of being handled.. handle_simple_irq() also unmasks when
    > > it finishes handling an interrupt (something real time adds for some
    > > reason) ..
    > >
    > > In terms of threading the irq everything is the same except there is no
    > > unmask() call when the thread finishes ..
    > >
    >
    > OK, to be honest, I never fully understood the concept of this
    > "simple_irq". I figured it was because of the ARM architecture.

    If you read what I said compared with what Daniel said, you'll see that
    adding the mask/unmask is _pointless_ because for the case where the
    simple handler should be used, there is _no_ hardware masking available
    except via the parent interrupt signal.

    So actually Daniel's argument misses the basic point - that using
    handle_simple_irq for non-simple IRQs is just WRONG.
    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2007-11-29 00:07    [W:0.021 / U:1.000 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site