From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ilias Apalodimas Subject: Re: [PATCH] clk: mvebu: armada-37xx-periph: Fix initialization for cpu clocks Date: Thu, 14 Mar 2019 14:15:41 +0200 Message-ID: <20190314121541.GB19385@apalos> References: <20190313163558.6705-1-gregory.clement@bootlin.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20190313163558.6705-1-gregory.clement@bootlin.com> Sender: stable-owner@vger.kernel.org To: Gregory CLEMENT Cc: Stephen Boyd , Mike Turquette , linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, "Rafael J. Wysocki" , Viresh Kumar , linux-pm@vger.kernel.org, Christian Neubert , Vincent Guittot , Jason Cooper , Andrew Lunn , Sebastian Hesselbarth , Thomas Petazzoni , linux-arm-kernel@lists.infradead.org, Antoine Tenart , =?iso-8859-1?Q?Miqu=E8l?= Raynal , Maxime Chevallier , stable@vger.kernel.org List-Id: linux-pm@vger.kernel.org Hi Gregory, > The clock parenting was not setup properly when DVFS was enabled. It was > expected that the same clock source was used with and without DVFS which > was not the case. > > This patch fixes this issue, allowing to make the cpufreq support work > when the CPU clocks source are not the default ones. > > Fixes: 92ce45fb875d ("cpufreq: Add DVFS support for Armada 37xx") > Cc: > Reported-by: Christian Neubert > Reported-by: Ilias Apalodimas > Signed-off-by: Gregory CLEMENT > --- > drivers/clk/mvebu/armada-37xx-periph.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/drivers/clk/mvebu/armada-37xx-periph.c b/drivers/clk/mvebu/armada-37xx-periph.c > index 1f1cff428d78..26ed3c18a239 100644 > --- a/drivers/clk/mvebu/armada-37xx-periph.c > +++ b/drivers/clk/mvebu/armada-37xx-periph.c > @@ -671,6 +671,17 @@ static int armada_3700_add_composite_clk(const struct clk_periph_data *data, > map = syscon_regmap_lookup_by_compatible( > "marvell,armada-3700-nb-pm"); > pmcpu_clk->nb_pm_base = map; > + > + /* > + * Use the same parent when DVFS is enabled that the > + * default parent received at boot time. When this > + * function is called, DVFS is not enabled yet, so we > + * get the default parent and we can set the parent > + * for DVFS. > + */ > + if (clk_pm_cpu_set_parent(muxrate_hw, > + clk_pm_cpu_get_parent(muxrate_hw))) > + dev_warn(dev, "Failed to setup default parent clock for DVFS\n"); > } > > *hw = clk_hw_register_composite(dev, data->name, data->parent_names, > -- > 2.20.1 > Applied this and selected only CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE=y CONFIG_CPU_FREQ_GOV_PERFORMANCE=y CONFIG_CPU_FREQ_GOV_POWERSAVE=y After changing the governor from 'powersave' to 'performance' the board completely froze (i even lost access to the serial port) Cheers /Ilias