From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jon Hunter Subject: Re: [PATCH] clk: tegra: fix SMP build Date: Wed, 12 Dec 2018 17:20:35 +0000 Message-ID: <583c04aa-7939-7401-b4e1-99bb6afe1485@nvidia.com> References: <20181211143528.2024488-1-arnd@arndb.de> <154454887151.17204.5632248748272979028@swboyd.mtv.corp.google.com> <20c5f3a9-fd82-5634-6a1e-6384c0facece@nvidia.com> <20181212133127.GB28521@ulmo> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20181212133127.GB28521@ulmo> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Thierry Reding Cc: Stephen Boyd , Arnd Bergmann , Michael Turquette , Peter De Schrijver , Prashant Gaikwad , Dmitry Osipenko , Aapo Vienamo , linux-clk@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-tegra@vger.kernel.org On 12/12/2018 13:31, Thierry Reding wrote: > On Wed, Dec 12, 2018 at 11:47:32AM +0000, Jon Hunter wrote: >> >> On 11/12/2018 17:21, Stephen Boyd wrote: >>> Quoting Arnd Bergmann (2018-12-11 06:35:07) >>>> When CONFIG_SMP is disabled, the tegra clk driver now fails to build: >>>> >>>> drivers/clk/tegra/clk-tegra30.c: In function 'tegra30_cpu_rail_off_ready': >>>> drivers/clk/tegra/clk-tegra30.c:1151:19: error: implicit declaration of function 'tegra_pmc_cpu_is_powered'; did you mean 'tegra_powergate_is_powered'? [-Werror=implicit-function-declaration] >>>> cpu_pwr_status = tegra_pmc_cpu_is_powered(1) || >>>> >>>> I don't know if tegra works without CONFIG_SMP, but we can get it to >>>> build by making the calls conditional, and removing the pointless >>>> ifdef around the declaration. The assumption now is that in a >>>> non-SMP system, the secondary CPUs are always disabled. >>>> >>>> Fixes: 61866523ed6e ("clk: tegra30: Use Tegra CPU powergate helper function") >>>> Signed-off-by: Arnd Bergmann >>>> --- >>>> Not sure if this is the best solution. If you think it's not, please >>>> submit a different fix. >>> >>> Hmm.. Is there any reason why the implementation of >>> tegra_pmc_cpu_is_powered() is under an ifdef CONFIG_SMP? I'd rather not >>> have to think about SMP or not in this clk code and have the >>> tegra_pmc_cpu_is_powered() function do the UP vs SMP code optimization. >> >> Not that I know of. I just think that the function should/would not be >> used for non-SMP. >> >> I was actually thinking that we could just leave the clk code as it is >> and simply drop the CONFIG_SMP from pmc.h. That would be fine with me. > > Yeah, I'd be fine keeping that code around whether or not we enable SMP. > Chances are people won't disable it anyway. If they do, then most likely > only for testing purposes, in which case I'm sure they won't mind the > extra couple of bytes. > > I think if we remove CONFIG_SMP from pmc.h we also need to remove it > from drivers/soc/tegra/pmc.c to make sure these functions are available, > otherwise we'll likely run into linker errors. > > Jon, is that something I can interest you in? If not, I can easily do > that myself. Yes I can do it (tomorrow). Cheers Jon -- nvpublic