On Wed, Apr 29, 2015 at 10:02:03AM -0700, Kevin Cernekee wrote: > On Wed, Apr 29, 2015 at 9:46 AM, Mark Brown <broonie@xxxxxxxxxx> wrote: > > We just need a single boolean? > Right, so if we add a per-regmap bool that tells us whether the device > has been reset, then in the case of "not reset" we will have to write > every regcache entry out to the device. Even the ones that weren't > touched while in cache_only mode. This makes the "not reset" case > much less efficient than the "reset" case. The immediate point is to provide a useful external interface, the internal optimisation is much less urgent (and it's less clear to me how often we're going to need to do that at all - generally cache only and power loss go together. > BTW, any preferences on naming for the bool or for the renamed > mark_dirty function? Not urgently. Note that I'm *not* suggesting an immediate rename, that's definitely a separate change (which will be a lot more painful to merge due to cross tree issues). > >> i.e. regcache_sync() finds a register value marked "present". How do > >> we know whether we need to write it back to the hardware? For the > >> special case of "cached non default register values immediately after > >> a HW reset" you can mostly figure this out, but if there was no HW > >> reset how do we know which entries changed while the HW was > >> inaccessible? > > In the first instance do we care? > I'm not sure I understand the question. Do we actually care about getting a list of the changed registers that much?
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