Messages in this thread | | | Date | Fri, 16 Jan 2015 18:36:35 +0000 | From | Mark Brown <> | Subject | Re: [RFC 2/3] regmap: Use the enhancement of i2c API to address circular dependency problem |
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On Fri, Jan 16, 2015 at 06:36:14PM +0100, Paul Osmialowski wrote: > On Fri, 16 Jan 2015, Mark Brown wrote:
> >I don't know what this means, sorry. I'm also very worried about the > >fact that this is being discussed purely in terms of I2C - why would > >this not affect other buses?
> I tried to open some gate for further extension to any bus that is used for > regmap communications. Currently it goes down to regmap-i2c.c since I > enhanced i2c API for this. Anyone who feels it is useful or saves oneself > from locking troubles can voluntarily adapt other regmap-i2c.* places (as > needed?).
> My whole point is that I proposed a way to solve nasty deadlock which is > better to fix than just leave as it is. I got a feeling that situation I > adressed here may occur others too, so I proposed this extension that allows > future adaptations. I don't expect it to be accepted easily (i.e. I'm new > here and have mixed feelins about proposing changes that go so far), > therefore I prepared other solution for this particular deadlock that occurs > on this particular device.
What I'm saying is that I want to understand this change from a point of view that isn't tied to I2C - at the regmap level what is this doing, I2C is a bus that has some properties which you're saying needs some changes, what are those properties and those changes?
> >>+ void (*reg_unprepare_sync_io)(void *context);
> >The first question here is why this only affects synchronous I/O or > >alternatively why these operations have _sync in the name if they aren't > >for synchronous I/O.
> IMHO this whole idea is against asynchronous I/O.
Can you be more specific please? If something needs preparing it seems like it'd need preparing over an async transaction just as much as over a synchronous one.
> >>+ if (bus) { > >>+ map->reg_prepare_sync_io = regmap_bus_prepare_sync_io; > >>+ map->reg_unprepare_sync_io = regmap_bus_unprepare_sync_io; > >>+ }
> >Why are we using these indirections instead of assigning the operation > >directly? They...
> I followed the pattern used throughout this file.
Not in this pattern where the caller needs to check too. [unhandled content-type:application/pgp-signature] | |