| Message ID | 20150109122120.GJ16465@ulmo |
|---|---|
| State | Accepted |
| Headers | show |
On 01/09/2015 01:21 PM, Thierry Reding wrote: > On Fri, Jan 09, 2015 at 09:31:08AM +0100, Daniel Lezcano wrote: >> On 01/09/2015 03:09 AM, Paul Walmsley wrote: >>> Hello Daniel >>> >>> On Thu, 8 Jan 2015, Daniel Lezcano wrote: >>> >>>> On 12/09/2014 11:07 PM, Paul Walmsley wrote: >>>>> >>>>> Like several of the other files in drivers/clocksource, >>>>> tegra20_timer.c contains code that can only compile when CONFIG_ARM is >>>>> enabled. This causes obvious problems when trying to compile this >>>>> code for NVIDIA ARM64-based SoCs, such as Tegra132. The same timer IP >>>>> blocks exist, so it seems appropriate to provide support for them. >>>>> >>>>> So until we figure out a better way to partition this code, wrap the >>>>> delay_timer and persistent_clock support code with preprocessor tests >>>>> for CONFIG_ARM. >>>>> >>>>> (The delay_timer code should not be needed at all on >>>>> ARM64 due to the presence of the ARMv8 architected timer. The >>>>> persistent_clock support code could become important once power >>>>> management modes are implemented that turn off the CPU complex.) >>>> >>>> IIUC, the cpuidle driver is not yet ready, right ? >>>> >>>> If it is the case, this driver is not needed yet, no ? >>> >>> The point of the patch is to allow the hardware drivers selected by >>> CONFIG_ARCH_TEGRA to build for an arm64 kernel, just as they build for >>> 32-bit ARM. >>> >>> There's nothing CPUIdle-specific about the patch - that is, this timer can >>> be selected as a clockevent and clocksource provider without the use of >>> CPUIdle - although low-power PM idle is likely to be a primary use-case. >> >> What I meant is this timer is not needed for the moment. >> >>>> Perhaps you can rework a bit this driver in the meantime to have a better fix >>>> than disabling the code with macros ? >>> >>> I'm happy to do that, but it would be nice to get the driver compiling >>> first for ARM64 :-) >>> >>>> Otherwise, please try at least to group the code into a minimal set of macros. >>> >>> So, would it be accurate to say that you would prefer a patch that changes >>> more lines of code, but minimizes preprocessor directives, to the current >>> patch? >> >> Yes at least an attempt to factor out a bit the driver. Those #ifdef are >> like #if 0, which is a quick fix. I am not strongly against this patch, but >> it would be nice to take the opportunity to reorganize it a bit. > > How about we do something like the attached patch instead for now. That > avoids any #ifdef'ery and still we don't attempt (and fail) to build the > driver on 64-bit ARM. > > With that applied we can incrementally make the changes to untangle the > ARM-specific parts and when the driver can build on 64-bit ARM we simply > select TEGRA_TIMER via Kconfig. Yes, that is exactly what I was thinking about after sending the previous email. And by this way, you also fixed the Kconfig option selection logic.
On Fri, Jan 09, 2015 at 02:24:24PM +0100, Daniel Lezcano wrote: > On 01/09/2015 01:21 PM, Thierry Reding wrote: > >On Fri, Jan 09, 2015 at 09:31:08AM +0100, Daniel Lezcano wrote: > >>On 01/09/2015 03:09 AM, Paul Walmsley wrote: > >>>Hello Daniel > >>> > >>>On Thu, 8 Jan 2015, Daniel Lezcano wrote: > >>> > >>>>On 12/09/2014 11:07 PM, Paul Walmsley wrote: > >>>>> > >>>>>Like several of the other files in drivers/clocksource, > >>>>>tegra20_timer.c contains code that can only compile when CONFIG_ARM is > >>>>>enabled. This causes obvious problems when trying to compile this > >>>>>code for NVIDIA ARM64-based SoCs, such as Tegra132. The same timer IP > >>>>>blocks exist, so it seems appropriate to provide support for them. > >>>>> > >>>>>So until we figure out a better way to partition this code, wrap the > >>>>>delay_timer and persistent_clock support code with preprocessor tests > >>>>>for CONFIG_ARM. > >>>>> > >>>>> (The delay_timer code should not be needed at all on > >>>>>ARM64 due to the presence of the ARMv8 architected timer. The > >>>>>persistent_clock support code could become important once power > >>>>>management modes are implemented that turn off the CPU complex.) > >>>> > >>>>IIUC, the cpuidle driver is not yet ready, right ? > >>>> > >>>>If it is the case, this driver is not needed yet, no ? > >>> > >>>The point of the patch is to allow the hardware drivers selected by > >>>CONFIG_ARCH_TEGRA to build for an arm64 kernel, just as they build for > >>>32-bit ARM. > >>> > >>>There's nothing CPUIdle-specific about the patch - that is, this timer can > >>>be selected as a clockevent and clocksource provider without the use of > >>>CPUIdle - although low-power PM idle is likely to be a primary use-case. > >> > >>What I meant is this timer is not needed for the moment. > >> > >>>>Perhaps you can rework a bit this driver in the meantime to have a better fix > >>>>than disabling the code with macros ? > >>> > >>>I'm happy to do that, but it would be nice to get the driver compiling > >>>first for ARM64 :-) > >>> > >>>>Otherwise, please try at least to group the code into a minimal set of macros. > >>> > >>>So, would it be accurate to say that you would prefer a patch that changes > >>>more lines of code, but minimizes preprocessor directives, to the current > >>>patch? > >> > >>Yes at least an attempt to factor out a bit the driver. Those #ifdef are > >>like #if 0, which is a quick fix. I am not strongly against this patch, but > >>it would be nice to take the opportunity to reorganize it a bit. > > > >How about we do something like the attached patch instead for now. That > >avoids any #ifdef'ery and still we don't attempt (and fail) to build the > >driver on 64-bit ARM. > > > >With that applied we can incrementally make the changes to untangle the > >ARM-specific parts and when the driver can build on 64-bit ARM we simply > >select TEGRA_TIMER via Kconfig. > > Yes, that is exactly what I was thinking about after sending the previous > email. And by this way, you also fixed the Kconfig option selection logic. Great. Will you give your Acked-by so that I can take that patch through the Tegra tree to resolve the build dependency? Thierry
On 01/09/2015 02:33 PM, Thierry Reding wrote: > On Fri, Jan 09, 2015 at 02:24:24PM +0100, Daniel Lezcano wrote: >> On 01/09/2015 01:21 PM, Thierry Reding wrote: >>> On Fri, Jan 09, 2015 at 09:31:08AM +0100, Daniel Lezcano wrote: >>>> On 01/09/2015 03:09 AM, Paul Walmsley wrote: >>>>> Hello Daniel >>>>> >>>>> On Thu, 8 Jan 2015, Daniel Lezcano wrote: >>>>> >>>>>> On 12/09/2014 11:07 PM, Paul Walmsley wrote: >>>>>>> >>>>>>> Like several of the other files in drivers/clocksource, >>>>>>> tegra20_timer.c contains code that can only compile when CONFIG_ARM is >>>>>>> enabled. This causes obvious problems when trying to compile this >>>>>>> code for NVIDIA ARM64-based SoCs, such as Tegra132. The same timer IP >>>>>>> blocks exist, so it seems appropriate to provide support for them. >>>>>>> >>>>>>> So until we figure out a better way to partition this code, wrap the >>>>>>> delay_timer and persistent_clock support code with preprocessor tests >>>>>>> for CONFIG_ARM. >>>>>>> >>>>>>> (The delay_timer code should not be needed at all on >>>>>>> ARM64 due to the presence of the ARMv8 architected timer. The >>>>>>> persistent_clock support code could become important once power >>>>>>> management modes are implemented that turn off the CPU complex.) >>>>>> >>>>>> IIUC, the cpuidle driver is not yet ready, right ? >>>>>> >>>>>> If it is the case, this driver is not needed yet, no ? >>>>> >>>>> The point of the patch is to allow the hardware drivers selected by >>>>> CONFIG_ARCH_TEGRA to build for an arm64 kernel, just as they build for >>>>> 32-bit ARM. >>>>> >>>>> There's nothing CPUIdle-specific about the patch - that is, this timer can >>>>> be selected as a clockevent and clocksource provider without the use of >>>>> CPUIdle - although low-power PM idle is likely to be a primary use-case. >>>> >>>> What I meant is this timer is not needed for the moment. >>>> >>>>>> Perhaps you can rework a bit this driver in the meantime to have a better fix >>>>>> than disabling the code with macros ? >>>>> >>>>> I'm happy to do that, but it would be nice to get the driver compiling >>>>> first for ARM64 :-) >>>>> >>>>>> Otherwise, please try at least to group the code into a minimal set of macros. >>>>> >>>>> So, would it be accurate to say that you would prefer a patch that changes >>>>> more lines of code, but minimizes preprocessor directives, to the current >>>>> patch? >>>> >>>> Yes at least an attempt to factor out a bit the driver. Those #ifdef are >>>> like #if 0, which is a quick fix. I am not strongly against this patch, but >>>> it would be nice to take the opportunity to reorganize it a bit. >>> >>> How about we do something like the attached patch instead for now. That >>> avoids any #ifdef'ery and still we don't attempt (and fail) to build the >>> driver on 64-bit ARM. >>> >>> With that applied we can incrementally make the changes to untangle the >>> ARM-specific parts and when the driver can build on 64-bit ARM we simply >>> select TEGRA_TIMER via Kconfig. >> >> Yes, that is exactly what I was thinking about after sending the previous >> email. And by this way, you also fixed the Kconfig option selection logic. > > Great. Will you give your Acked-by so that I can take that patch through > the Tegra tree to resolve the build dependency? Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
On Fri, Jan 09, 2015 at 02:38:39PM +0100, Daniel Lezcano wrote: > On 01/09/2015 02:33 PM, Thierry Reding wrote: > >On Fri, Jan 09, 2015 at 02:24:24PM +0100, Daniel Lezcano wrote: > >>On 01/09/2015 01:21 PM, Thierry Reding wrote: [...] > >>>How about we do something like the attached patch instead for now. That > >>>avoids any #ifdef'ery and still we don't attempt (and fail) to build the > >>>driver on 64-bit ARM. > >>> > >>>With that applied we can incrementally make the changes to untangle the > >>>ARM-specific parts and when the driver can build on 64-bit ARM we simply > >>>select TEGRA_TIMER via Kconfig. > >> > >>Yes, that is exactly what I was thinking about after sending the previous > >>email. And by this way, you also fixed the Kconfig option selection logic. > > > >Great. Will you give your Acked-by so that I can take that patch through > >the Tegra tree to resolve the build dependency? > > Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Thanks, Thierry
From dccf6b8e0dcf5695eb29a8749406472e578b972e Mon Sep 17 00:00:00 2001 From: Thierry Reding <treding@nvidia.com> Date: Mon, 7 Jul 2014 15:26:30 +0200 Subject: [PATCH] clocksource: Build Tegra timer on 32-bit ARM only Instead of directly using the ARCH_TEGRA Kconfig symbol to enable this driver, add a new, non-user-visible Kconfig symbol (TEGRA_TIMER) which can be selected by the various SoCs. This is useful to disable building the driver on Tegra132 (64-bit ARM) where it doesn't currently compile but also isn't needed (yet). Signed-off-by: Thierry Reding <treding@nvidia.com> --- arch/arm/mach-tegra/Kconfig | 4 ++++ drivers/clocksource/Kconfig | 3 +++ drivers/clocksource/Makefile | 2 +- 3 files changed, 8 insertions(+), 1 deletion(-) diff --git a/arch/arm/mach-tegra/Kconfig b/arch/arm/mach-tegra/Kconfig index f87684e600c7..667a48e2f7d4 100644 --- a/arch/arm/mach-tegra/Kconfig +++ b/arch/arm/mach-tegra/Kconfig @@ -29,6 +29,7 @@ config ARCH_TEGRA_2x_SOC select PINCTRL_TEGRA20 select PL310_ERRATA_727915 if CACHE_L2X0 select PL310_ERRATA_769419 if CACHE_L2X0 + select TEGRA_TIMER help Support for NVIDIA Tegra AP20 and T20 processors, based on the ARM CortexA9MP CPU and the ARM PL310 L2 cache controller @@ -39,6 +40,7 @@ config ARCH_TEGRA_3x_SOC select ARM_ERRATA_764369 if SMP select PINCTRL_TEGRA30 select PL310_ERRATA_769419 if CACHE_L2X0 + select TEGRA_TIMER help Support for NVIDIA Tegra T30 processor family, based on the ARM CortexA9MP CPU and the ARM PL310 L2 cache controller @@ -49,6 +51,7 @@ config ARCH_TEGRA_114_SOC select ARM_L1_CACHE_SHIFT_6 select HAVE_ARM_ARCH_TIMER select PINCTRL_TEGRA114 + select TEGRA_TIMER help Support for NVIDIA Tegra T114 processor family, based on the ARM CortexA15MP CPU @@ -58,6 +61,7 @@ config ARCH_TEGRA_124_SOC select ARM_L1_CACHE_SHIFT_6 select HAVE_ARM_ARCH_TIMER select PINCTRL_TEGRA124 + select TEGRA_TIMER help Support for NVIDIA Tegra T124 processor family, based on the ARM CortexA15MP CPU diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index fc01ec27d3c8..c062b6105d49 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -47,6 +47,9 @@ config SUN5I_HSTIMER select CLKSRC_MMIO bool +config TEGRA_TIMER + bool + config VT8500_TIMER bool diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index 94d90b24b56b..ba9ebd868ec5 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -27,7 +27,7 @@ obj-$(CONFIG_ARCH_U300) += timer-u300.o obj-$(CONFIG_SUN4I_TIMER) += sun4i_timer.o obj-$(CONFIG_SUN5I_HSTIMER) += timer-sun5i.o obj-$(CONFIG_MESON6_TIMER) += meson6_timer.o -obj-$(CONFIG_ARCH_TEGRA) += tegra20_timer.o +obj-$(CONFIG_TEGRA_TIMER) += tegra20_timer.o obj-$(CONFIG_VT8500_TIMER) += vt8500_timer.o obj-$(CONFIG_ARCH_NSPIRE) += zevio-timer.o obj-$(CONFIG_ARCH_BCM_MOBILE) += bcm_kona_timer.o -- 2.1.3