Antti/Mark, Any news with regards to this? Regards, Mauro Em Mon, 22 Dec 2014 15:05:15 +0000 Mark Brown <broonie@xxxxxxxxxx> escreveu: > On Mon, Dec 22, 2014 at 03:53:10PM +0200, Antti Palosaari wrote: > > On 12/22/2014 03:31 PM, Mark Brown wrote: > > > >>>Why is this configurable, how would a device know if the system it is in > > >>>needs a custom locking class and can safely use one? > > > >>If RegMap instance is bus master, eg. I2C adapter, then you should define > > >>own custom key. If you don't define own key and there will be slave on that > > >>bus which uses RegMap too, there will be recursive locking from a lockdep > > >>point of view. > > > >That doesn't really explain to me why this is configurable, why should > > >drivers have to worry about this? > > > Did you read the lockdep documentation I pointed previous mail? > > No, quite apart from the fact that you pasted a good chunk of it into > your mail I don't think it's a good idea to require people to have to > reverse engineer everything to figure out if they're supposed to use > this, or expect people reviewing code using this feature to do that in > order to figure out if it's being used correctly or not. > > Suggesting that I'm not thinking hard enough isn't helping here; this > stuff needs to be clear and easy so that people naturally get it right > when they need to and don't break things as a result of confusion or > error, requiring people to directly work with infrequently used things > like lock classes with minimal explanation doesn't achieve that goal. > > > One possibility is to disable lockdep checking from that driver totally, > > then drivers do not need to care it about. But I don't think it is proper > > way. One solution is to use custom regmap locking available already, but > > Mauro nor me didn't like that hack: > > You don't seem to be answering any of my questions here... for example, > you keep saying that this is something bus masters should do. Why does > it make sense for people writing such drivers to have to figure out that > they need to do this and how to do it? Are there some bus masters that > shouldn't be doing so? Should anything that isn't a bus master have to > do it? > > > >Please also write technical terms like regmap normally. > > > Lower-case letters? > > Yes, the way it's written in every place it's used in the kernel except > a few I see you've added. -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
