Messages in this thread | | | Date | Wed, 31 Jul 2013 17:04:14 -0700 | From | Stephen Boyd <> | Subject | Re: [PATCH 2/2] Convert PowerPC macro spin_event_timeout() to architecture independent macro |
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On 07/31/13 16:44, Timur Tabi wrote: > On Wed, Jul 31, 2013 at 2:16 AM, Stephen Boyd <sboyd@codeaurora.org> wrote: >> What do you do here if jiffies aren't incrementing (i.e >> interrupts are disabled). The time_before() check won't work >> there and it would be nice if we were able to use this in such >> situations. I think powerpc gets around this by reading the >> hardware timer directly? > I believe that jiffies is always a global variable. It should behave > the same on PowerPC as on other architectures.
Yes it's global but it doesn't increment while interrupts are off.
> > The answer to your question is that you should not use > spin_event_timeout() in interrupt context, because it yields. >
If it yields why are we using udelay? Why not usleep_range()? It would be useful to have a variant that worked in interrupt context and it looked like that was almost possible.
BTW, couldn't we skip the first patch and just use usecs_to_jiffies()?
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