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 16:15:29 +0200 Message-ID: <20190314141529.GA5576@apalos> References: <20190313163558.6705-1-gregory.clement@bootlin.com> <20190314121541.GB19385@apalos> <20190314134428.GA24768@apalos> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Christian Neubert Cc: Gregory CLEMENT , Stephen Boyd , Mike Turquette , linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, "Rafael J. Wysocki" , Viresh Kumar , linux-pm@vger.kernel.org, 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, > Hi, > > the cpu frequency scaling never worked right (only on the 4.4 kernel from > marvell). If you use the 1000 MHz firmware you are running with just 800 > MHz (this is the case on my board with a current firmware). > > Just have a look what the kernel thinks it is running at (frequency). Ok, probably my bad here. By 'worked fine' i mean that this didn't lead to any freezes or panics. I know the actual frequency wasn't set properly Regards /Ilias > > Regards, > Christian > > Ilias Apalodimas schrieb am Do., 14. März > 2019, 14:44: > > > Hello Christian, > > > Hi, > > > > > > I assume you use the 1000 MHz firmware. This does also not work on my > > Rev 7 > > > board. But I'm pretty sure this is not a problem of the patches, because > > if > > > I take a newer kernel (4.19.20/27) without the patches it also does not > > > work. A kernel 4.19.17 does work for me. My opinion on that is that this > > is > > > another problem which does just occure now because now the cpu frequency > > > scaling is working with the right frequencies. > > I am not sure which firmware i am running, i did all my tests on 5.0.0 and > > changing between governors worked fine without the patches > > > > Regards > > /Ilias > > > > > > Ilias Apalodimas schrieb am Do., 14. März > > > 2019, 13:15: > > > > > > > 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 > > > > > >