Chanwoo Choi wrote: > Hi Kukjin Kim, > > Please reply about Sylwester Nawrocki and me. > 2011/11/3 Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx> > Hi Kgene, > > On 11/03/2011 03:09 AM, Kukjin Kim wrote: > > As I said, I don't think we should control/gate the clocks with regarding power domain. > As far as I know there is a plan to let the drivers override start/stop_device callbacks, > moreover the clock control can be disabled globally by not implementing start/stop_device > callbacks or per device by not adding clkdev entities to the device clock list at runtime > PM core. So IMHO, there is/going to be enough flexibility. > > > It should be controlled by each regarding device driver and in addition, as I know, > > to handle block of clock is not recommended on EXYNOS4 now. > What do you mean by this ? I couldn't find such information in any documentation. > Shouldn't "clock gate block" registers be touched by boot loader and the kernel? > Our boot loaders disable all clocks, and if the global clock gate is not enabled > by the kernel there is no chance any multimedia device will work. > > Should the global clock block gate be always enabled then ? I'm afraid it is not > optimal form power management POV. > Sylwester, let me check again before replying. > To Kukjin Kim, > Hi Chanwoo, Firstly, please use text-typed e-mail when you reply. > > It should be controlled by each regarding device driver and in addition, as I know, > > to handle block of clock is not recommended on EXYNOS4 now. > > As you said, should we separately control power and clock of power domain? If you ask my opinion, yes, I mean when it is required, it would be controlled independent. > or Have to turn on the clock of power domain always? I didn't say like that. > I think that it is to happen unnecessary power consumption. I don't think, when the power of block/domain is downed, does it happen _really_ meaningful power consumption? > If we have to maintain on state of power domain clock, please let me know guide about this. > > Also, > For example, fimg2d and framebuffer use LCD0 power domain as parent device.I > If fimg2d and framebuffer is disabled state due to not using their, > I think that we should turn off the clock of LCD0 power domain to reduce power leakage. I think, probably it doesn't matter. If any useful data, please let me know. > Which each regarding device driver control the clock of power domain? > > I will expect for your reply. > Thanks. Best regards, Kgene. -- Kukjin Kim <kgene.kim@xxxxxxxxxxx>, Senior Engineer, SW Solution Development Team, Samsung Electronics Co., Ltd. _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/linux-pm
