On Tue, Feb 16, 2016 at 04:31:48PM +0100, Geert Uytterhoeven wrote: > Hi Simon, Magnus, > > All supported Renesas ARM SoCs (except for Emma Mobile EV2) have clock > domains. Some SoCs also have power domains. To ensure proper operation > of on-SoC modules, module clocks must be ungated, and power domains must > be powered up when needed. > > Currently the user can choose to build a kernel with power management > enabled or disabled: > - If CONFIG_PM=y, power domains and/or module clocks are handled > dynamically by Runtime PM and the generic power domain. > - If CONFIG_PM=n, power domains are assumed to be powered up by reset > state or by the boot loader, and module clocks are handled by the > legacy clock domain on driver (un)bind. > The latter is implemented using a platform bus notifier, which > applies not only to all on-SoC devices, but to all platform devices > present in the system. > > To remove the dependency on implicit assumptions, and to get rid of the > peculiarities of the legacy clock domain, enable CONFIG_PM and > CONFIG_PM_GENERIC_DOMAINS unconditionally, for all Renesas ARM SoCs with > clock and/or power domains. > > Patches: > - Patches 1 and 2 enable PM and PM_GENERIC_DOMAINS, > - Patch 3 removes the now unused legacy clock domain code for Renesas > ARM SoCs, > - Patch 4 relieves you from maintaining drivers/sh/, which is no > longer used on Renesas ARM SoCs, and returns it to the SuperH > people. > > Notes: > - This does cause an increase in kernel size. Given bloat-o-meter > reports a modest increase of 26 KiB for an RZ/A1H kernel, this > should not be a problem, even when used on RZ/A1H with XIP and > internal RAM only. > - Patch 3 does break booting R-Car Gen2 boards using pre-v4.3 DTSes > that don't have power-domains properties, > - Patch 3 may unbreak SuperH-based ARCH_SHMOBILE platforms, which were > probably broken since v4.4 by commit 0ba58de231066e47 ("drivers: sh: > Get rid of CONFIG_ARCH_SHMOBILE_MULTI"), > - Currently CONFIG_PM=n doesn't work anyway on r8a7795 as "drivers: > sh: Handle PM_GENERIC_DOMAINS_OF=n with new r8a7795 CPG/MSSR > driver" isn't upstream. > > For your convenience, I've also pushed this series to > git://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-drivers.git#topic/mandatory-pm-v1 > > Thanks for your comments! > > Geert Uytterhoeven (4): > ARM: shmobile: Enable PM and PM_GENERIC_DOMAINS for SoCs with PM > Domains > arm64: renesas: Enable PM and PM_GENERIC_DOMAINS for SoCs with PM > Domains
Thanks, I have tentatively queued up the above two patches for v4.6. With regards to the remaining two patches, I propose deferring them for a few releases so that we can shake out any regressions that may occur before making a compatibility change. > drivers: sh: Stop using the legacy clock domain on ARM > MAINTAINERS: Drop drivers/sh/ for Renesas ARM > > MAINTAINERS | 1 - > arch/arm/mach-shmobile/Kconfig | 13 ++++++++----- > arch/arm64/Kconfig.platforms | 3 ++- > drivers/Makefile | 1 - > drivers/sh/pm_runtime.c | 9 --------- > 5 files changed, 10 insertions(+), 17 deletions(-)