From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dirk Behme Subject: Re: Clocks used by another OS/CPU Date: Thu, 29 Jun 2017 14:07:38 +0200 Message-ID: <50911172-8fa1-8341-0ed0-d40f00d9392c@de.bosch.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Language: en-US Sender: linux-clk-owner@vger.kernel.org To: Geert Uytterhoeven Cc: Michael Turquette , Stephen Boyd , Rob Herring , Mark Rutland , Ulf Hansson , "Rafael J. Wysocki" , Kevin Hilman , Linux-Renesas , linux-clk , "linux-arm-kernel@lists.infradead.org" , "devicetree@vger.kernel.org" , Linux PM list List-Id: linux-pm@vger.kernel.org On 29.06.2017 13:56, Geert Uytterhoeven wrote: > Hi Dirk, > > On Thu, Jun 29, 2017 at 11:27 AM, Geert Uytterhoeven > wrote: >> CC clock, ARM, DT, PM people >> >> TL;DR: Clocks may be in use by another CPU not running Linux, while Linux >> disables them as being unused. > >> Of course this is not limited to clocks, but also to e.g. PM domains. > > BTW, how do you prevent Linux from powering down the CR7 PM domain, > which contains the Cortex R7? The idea is --- a/drivers/soc/renesas/r8a7795-sysc.c +++ b/drivers/soc/renesas/r8a7795-sysc.c @@ -38,7 +38,8 @@ static const struct rcar_sysc_area r8a7795_areas[] __initconst = { { "ca53-cpu3", 0x200, 3, R8A7795_PD_CA53_CPU3, R8A7795_PD_CA53_SCU, PD_CPU_NOCR }, { "a3vp", 0x340, 0, R8A7795_PD_A3VP, R8A7795_PD_ALWAYS_ON }, - { "cr7", 0x240, 0, R8A7795_PD_CR7, R8A7795_PD_ALWAYS_ON }, + { "cr7", 0x240, 0, R8A7795_PD_CR7, R8A7795_PD_ALWAYS_ON, + PD_CPU_NOCR }, { "a3vc", 0x380, 0, R8A7795_PD_A3VC, R8A7795_PD_ALWAYS_ON }, { "a2vc0", 0x3c0, 0, R8A7795_PD_A2VC0, R8A7795_PD_A3VC }, { "a2vc1", 0x3c0, 1, R8A7795_PD_A2VC1, R8A7795_PD_A3VC }, Not finally tested, though. Best regards Dirk