From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 76D2417748; Mon, 4 Mar 2024 08:15:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709540137; cv=none; b=fYkmm8oujzcxJr3VqEGAPUlhb3UG0njSoeldMTrvxltx8a95oCdLUF2AVYFeB9xfWbS+Trpk4+O+sTfoUwBQndSpysgPWBDdHOOCjQ2lmy/lX/vAyO989LKN2SpyJkcmyKrOt9uzhx9efbhih+ab1n0ENpBpXFhbiRtEb8Ek3J8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709540137; c=relaxed/simple; bh=sIV4GFAFMe2hM+lUcfPmThwDZ5aRzv2IyHc/aTyBPug=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=iac1tmI1i33w+Gppl3mfa3XTBb4NsJa9rBPWylT9Ghh15m3JHlSfAC8JkwytAp5YFsKNJwYYuDDJ+Swkt0cEnLXtvcn92XPzRlrFjxKL/WSjzGZeFHlrskb/a4iQAhkhgkOErclA9BYv+2YzwHzFXvj3enQKpF8+OQox5ns9ycw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id AB37B1FB; Mon, 4 Mar 2024 00:16:11 -0800 (PST) Received: from pluto (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 750153F762; Mon, 4 Mar 2024 00:15:33 -0800 (PST) Date: Mon, 4 Mar 2024 08:15:31 +0000 From: Cristian Marussi To: Pierre Gondois Cc: linux-kernel@vger.kernel.org, Christian Loehle , Ionela Voinescu , Sudeep Holla , Dietmar Eggemann , "Rafael J. Wysocki" , Viresh Kumar , linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org Subject: Re: [PATCH 3/3] cpufreq: scmi: Set transition_delay_us Message-ID: References: <20240222135702.2005635-1-pierre.gondois@arm.com> <20240222135702.2005635-4-pierre.gondois@arm.com> Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240222135702.2005635-4-pierre.gondois@arm.com> On Thu, Feb 22, 2024 at 02:57:01PM +0100, Pierre Gondois wrote: > Make use of the newly added callbacks: > - rate_limit_get() > - fast_switch_rate_limit() > to populate policies's `transition_delay_us`, defined as the > 'Preferred average time interval between consecutive > invocations of the driver to set the frequency for this policy.' > > Signed-off-by: Pierre Gondois > --- > drivers/cpufreq/scmi-cpufreq.c | 26 ++++++++++++++++++++++++++ > 1 file changed, 26 insertions(+) > Hi, > diff --git a/drivers/cpufreq/scmi-cpufreq.c b/drivers/cpufreq/scmi-cpufreq.c > index 4ee23f4ebf4a..0b483bd0d3ca 100644 > --- a/drivers/cpufreq/scmi-cpufreq.c > +++ b/drivers/cpufreq/scmi-cpufreq.c > @@ -144,6 +144,29 @@ scmi_get_cpu_power(struct device *cpu_dev, unsigned long *power, > return 0; > } > > +static int > +scmi_get_rate_limit(u32 domain, bool has_fast_switch) > +{ > + int ret, rate_limit; > + > + if (has_fast_switch) { > + /* > + * Fast channels are used whenever available, > + * so use their rate_limit value if populated. > + */ > + ret = perf_ops->fast_switch_rate_limit(ph, domain, > + &rate_limit); > + if (!ret && rate_limit) > + return rate_limit; > + } > + > + ret = perf_ops->rate_limit_get(ph, domain, &rate_limit); > + if (ret) > + return 0; > + > + return rate_limit; > +} > + > static int scmi_cpufreq_init(struct cpufreq_policy *policy) > { > int ret, nr_opp, domain; > @@ -250,6 +273,9 @@ static int scmi_cpufreq_init(struct cpufreq_policy *policy) > policy->fast_switch_possible = > perf_ops->fast_switch_possible(ph, domain); > > + policy->transition_delay_us = > + scmi_get_rate_limit(domain, policy->fast_switch_possible); > + > return 0; > As a second thought, I have just realized that now we have 2 ops to get the rate_limit for a domain, one used in case of FCs and another in case of std messaging w/out FCs, BUT given that we always use FCs when available, AND we do not indeed have any way from perf_ops to explicitly request a set/get ops NOT to use FCs when available, does it even make sense to expose such 2 functions ? Do we need such flexibility ? Shouldn't we just expose one single rate_limit perf_ops and let the SCMI core decide what to return depending on the presence or not of the FCs for that domain ? Maybe @Sudeep thinks differently. Thanks, Cristian