Hi Pavel, Rafael, Do you have some other hints I could follow in order to solve the scenario I tried to cover with these patches, if these are not a proper fit for the current code?
Thank you, Claudiu Beznea On 08.01.2019 12:56, Claudiu Beznea - M18063 wrote: > From: Claudiu Beznea <[email protected]> > > Hi, > > AT91 platforms support a power saving mode where SoC's power is cut off (we > call > it backup mode). The resume is done with the help of bootloaders. To be able > to > suspend/resume Linux to/from this mode all the drivers suspend/resume > callbacks > should save/restore the content of all the active registers. We have 2 > problems > we are trying to solve: > - some of these drivers are shared with other non Microchip SoCs (e.g. macb > driver) and we don't want to disturbe other users of corresponding IPs with > all the register save/restore operations; > - the suspend/resume time for the rest of the power saving mode we are using > could be improved if we would know in drivers the suspend mode the platform > is switched to. > > A solution that would have been solve our problems was proposed in [1] but in > the end it wasn't accepted. It ended up with the introduction of > pm_suspend_target_state variable that could be used along with the changes in > this series. > > While the discussion of [1] progressed it has been proposed (in [2]) to > implement a function that would tell if the platform's power would be cut off > at the end of the suspend procedure. > > The patches in this series does as follows: > 1/3 - add a new member to platform_suspend_ops that will tell if platform's > power will be cut off at the end of the suspend procedure; drivers could > use it via platform_off_in_suspend() > 2/3 - add a new function to regulator's core that could be used to check if a > proper regulator has been configured (via DT) to be powered off in > suspend. This is used on this series to check the CPU's regulator is > properly configured in DT to be turned off in suspend. > 3/3 - fill .off_in_suspend member of at91_pm_ops; the functionality in patch > 2/3 > is used to double check CPU's regulator would be turned off in suspend. > > Thank you, > Claudiu Beznea > > [1] https://lkml.org/lkml/2017/6/22/938 > [2] https://lkml.org/lkml/2017/7/16/457 > > Changes in v2: > - remove !! instruction in regulator_is_disabled_in_suspend() and > at91_pm_state_allowed() > - s/weather/wether in patch 1/1 > > Claudiu Beznea (3): > PM / Suspend: Add support to check if platform's power is off in > suspend > regulator: core: add helper to check if regulator is disabled in > suspend > ARM: at91: pm: add support for .off_in_suspend > > arch/arm/mach-at91/pm.c | 61 > +++++++++++++++++++++++++++++++++++--- > drivers/regulator/core.c | 17 +++++++++++ > include/linux/regulator/consumer.h | 7 +++++ > include/linux/suspend.h | 6 ++++ > kernel/power/suspend.c | 13 ++++++++ > 5 files changed, 100 insertions(+), 4 deletions(-) >
