On Tue, May 29, 2018 at 12:04 PM, Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote: > Changes in v2: > - Addressed comments from Geert around DT doc. > - Addressed comments from Jon around clarification of how to use this > and changes to returned error codes. > - Fixed build error in case CONFIG_PM was unset. > > There are devices that are partitioned across multiple PM domains. Currently > these can't be supported well by the available PM infrastructures we have in > the kernel. This series is an attempt to address this. > > The interesting parts happens from patch 5 an onwards, including a minor DT > update to the existing power-domain bindings, the 4 earlier are just trivial > clean-ups of some related code in genpd, which I happened to stumble over. > > Some additional background: > > One existing case where devices are partitioned across multiple PM domains, is > the Nvida Tegra 124/210 X-USB subsystem. A while ago Jon Hunter (Nvidia) sent a > series, trying to address these issues, however this is a new approach, while > it re-uses the same concepts from DT point of view. > > The Tegra 124/210 X-USB subsystem contains of a host controller and a device > controller. Each controller have its own independent PM domain, but are being > partitioned across another shared PM domain for the USB super-speed logic. > > Currently to make the drivers work, either the related PM domains needs to stay > powered on always or the PM domain topology needs to be in-correctly modelled > through sub-domains. In both cases PM domains may be powered on while they > don't need to be, so in the end this means - wasting power -. > > As stated above, this series intends to address these problem from a PM > infrastructure point of view. More details are available in each changelog. > > It should be noted that this series has been tested on HW, however only by using > a home-cooked test PM domain driver for genpd and together with a test driver. > This allowed me to play with PM domain (genpd), runtime PM and device links. > > Any further deployment for real use cases are greatly appreciated. I am happy to > to help, if needed! > > Kind regards > Ulf Hansson > > > Ulf Hansson (9): > PM / Domains: Drop extern declarations of functions in pm_domain.h > PM / Domains: Drop __pm_genpd_add_device() > PM / Domains: Drop genpd as in-param for pm_genpd_remove_device() > PM / Domains: Drop unused parameter in genpd_allocate_dev_data() > PM / Domains: dt: Allow power-domain property to be a list of > specifiers > PM / Domains: Don't attach devices in genpd with multi PM domains > PM / Domains: Split genpd_dev_pm_attach() > PM / Domains: Add support for multi PM domains per device to genpd > PM / Domains: Add dev_pm_domain_attach_by_id() to manage multi PM > domains > > .../bindings/power/power_domain.txt | 19 ++- > drivers/base/power/common.c | 39 ++++- > drivers/base/power/domain.c | 155 ++++++++++++++---- > drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c | 2 +- > include/linux/pm_domain.h | 79 ++++----- > 5 files changed, 216 insertions(+), 78 deletions(-) I can take patches [1-4/9] from this series for 4.18. I need an ACK from Rob on the bindings change. The rest of the series doesn't seem to be ready yet. Thanks, Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
