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
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