Hi Ben,
On Sunday 12 January 2014 22:54:15 Laurent Pinchart wrote:
> Hi Ben,
>
> Thank you for the patch.
>
> On Saturday 11 January 2014 13:06:29 Ben Dooks wrote:
> > If the kernel is built to support multi-arm configurmation with shmobile
> > support built in, then the drivers/sh is not built. This contains drivers
> > that are essential to devices support by that configuration, including the
> > PM runtime code in drivers/sh/pm_runtime.c (which implicitly enables the
> > bus clocks for all devices).
Thinking a bit more about this, I think the approach taken in
drivers/sh/pm_runtime.c isn't good. The code enables device clocks when
devices are bound to a driver, increasing power consumption when devices are
idle. Instead of enabling it for ARCH_SHMOBILE_MULTI I'd like to either add
explicit clock support to drivers, or to integrate clocks with runtime PM
only.
> > If CONFIG_ARCH_SHMOBILE_MULTI then build the drivers/sh directory,
> > but ensure that bits that may conflict (drivers/sh/clk if the common
> > clock framework is not enabled) are built.
> >
> > The ARCH_SHMOBILE_MULTI was added by efacfce5f8a ("ARM: shmobile:
> > Introduce ARCH_SHMOBILE_MULTI") but this has only just recently been found
> > due to building device-tree only kernels.
> >
> > Cc: Linux Kernel list <linux-kernel@vger.kernel.org>
> > Cc: Linus SH list <linux...@vger.kernel.org>
> > Cc: Simon Horman <ho...@verge.net.au>
> > Cc: Magnus Damm <magnus.d...@gmail.com>
> > Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
> > Signed-off-by: Ben Dooks <ben.do...@codethink.co.uk>
> > ---
> >
> > drivers/Makefile | 1 +
> > drivers/sh/Makefile | 3 +++
> > 2 files changed, 4 insertions(+)
> >
> > diff --git a/drivers/Makefile b/drivers/Makefile
> > index 8e3b8b0..abc4744 100644
> > --- a/drivers/Makefile
> > +++ b/drivers/Makefile
> > @@ -118,6 +118,7 @@ obj-$(CONFIG_SGI_SN) += sn/
> >
> > obj-y += firmware/
> > obj-$(CONFIG_CRYPTO) += crypto/
> > obj-$(CONFIG_SUPERH) += sh/
> >
> > +obj-$(CONFIG_ARCH_SHMOBILE_MULTI) += sh/
> >
> > obj-$(CONFIG_ARCH_SHMOBILE_LEGACY) += sh/
> > ifndef CONFIG_ARCH_USES_GETTIMEOFFSET
> > obj-y += clocksource/
> >
> > diff --git a/drivers/sh/Makefile b/drivers/sh/Makefile
> > index fc67f56..86604a5 100644
> > --- a/drivers/sh/Makefile
> > +++ b/drivers/sh/Makefile
> > @@ -3,7 +3,10 @@
> >
> > #
> > obj-y := intc/
>
> Is intc needed as well ?
>
> > +ifeq ($(CONFIG_COMMON_CLK),n)
> >
> > obj-$(CONFIG_HAVE_CLK) += clk/
> >
> > +endif
> > +
> >
> > obj-$(CONFIG_MAPLE) += maple/
> > obj-$(CONFIG_SUPERHYWAY) += superhyway/
--
Regards,
Laurent Pinchart
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