On Wed, Aug 22, 2018 at 07:22:20AM -0700, Tony Lindgren wrote: > * J, KEERTHY <j-keerthy@xxxxxx> [180822 11:11]: > > On 8/22/2018 2:13 PM, Johan Hovold wrote: > > > Yes, and a blacklist would make much more sense for something like this > > > if where talking about specific boards. > > > > Black list is easier here? > > After thinking about this a bit more I think the boards supporting > deep sleep should add a PM related dts property to enable deep sleep. > > The board maintainers need to test and verify deep sleep for each > board, it's not something that just works for the SoC in general. > Some boards may use different powering for things like DDR where > it's power might be controlled by a GPIO regulator. And in some > cases deeper idle states may depend also on the PMIC being used. > > Maybe we already have some dts property we can use to describe > the idle states the board hardware supports? Yeah, unless you can infer this from an existing tree I guess you need to add a new property. And indeed, a driver blacklist would suffer from the same fundamental problem (with an ever expanding list of machines) as a whitelist even if it would avoid regressing currently working systems. Johan
