Messages in this thread | | | From | David Brownell <> | Subject | Re: [patch 2.6.24-rc2 1/3] generic gpio -- gpio_chip support | Date | Wed, 14 Nov 2007 22:23:45 -0800 |
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On Tuesday 13 November 2007, Nick Piggin wrote: > > > But these ones > > > are raw locks rather than normal locks probably because that > > > they are trivially an innermost and correct lock. > > > > As in the $SUBJECT case, I'd say. > > > > Although another point is related to "trivial": the data > > is being protected through an operation too trivial to be > > worth paying for any of that priority logic. > > A driver shouldn't get to decide that, IMO.
Not that I was talking about driver code...
> And if there is > some policy in the -rt tree allowing these decisions, then > it's exactly the kind of thing we don't want upsream.
Making raw spinlocks available allows those decisions...
On the other hand, I can't see things working sanely without them being available. The problem seems to be the usual one that crops up whenever anyone tries to create a "bright line" decision algorithm in areas that need flexibility. Any "bright line" rule will lead to wrong results.
- Dave
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