From mboxrd@z Thu Jan 1 00:00:00 1970 From: jeffy Subject: Re: [PATCH] devfreq: simple_ondemand: Update devfreq stats when governor started Date: Wed, 19 Jul 2017 12:28:27 +0800 Message-ID: <596EDFEB.4030500@rock-chips.com> References: <1500372171-7194-1-git-send-email-jeffy.chen@rock-chips.com> <20170718103549epcms1p87cf1d138e35426be0f95afa61fcebc85@epcms1p8> <596DF09E.10405@rock-chips.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from regular1.263xmail.com ([211.150.99.136]:52285 "EHLO regular1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750822AbdGSE2i (ORCPT ); Wed, 19 Jul 2017 00:28:38 -0400 In-Reply-To: <596DF09E.10405@rock-chips.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: myungjoo.ham@samsung.com, "linux-kernel@vger.kernel.org" Cc: "rui.zhang@intel.com" , "briannorris@chromium.org" , "javi.merino@kernel.org" , "dianders@chromium.org" , "lukasz.luba@arm.com" , Chanwoo Choi , Kyungmin Park , "linux-pm@vger.kernel.org" Hi Ham, oops, sorry, it turns out the devfreq would already tried to handle this case(by using profile's initial_freq): 8d39fc0 PM / devfreq: fix initialization of current frequency in last status and my local kernel didn't contains this commit. so this patch is not needed, please ignore it. On 07/18/2017 07:27 PM, jeffy wrote: > hi Ham, > > Thanks for your reply. > > On 07/18/2017 06:35 PM, MyungJoo Ham wrote: >>> If governor suspends soon after started, it may not have the chance to >>> update devfreq stats, which leaves devfreq stats' current frequence be >>> zero. >>> >>> So when the thermal core tries to throttle the power, it would failed >>> to get the correct static power of current frequence and print these >>> warnings: >>> [ 2.024735] core: dev_pm_opp_get_voltage: Invalid parameters >>> [ 2.024743] mali ff9a0000.gpu: Failed to get voltage for frequency 0: >>> -34 >>> ... >>> [ 2.026320] core: dev_pm_opp_get_voltage: Invalid parameters >>> [ 2.026327] mali ff9a0000.gpu: Failed to get voltage for frequency 0: >>> -34 >>> >>> Update devfreq stats when governor started to avoid that. >>> >>> Signed-off-by: Jeffy Chen >> >> How are you calling suspend/resume routins in the mali drivers? >> > i was porting mali driver from here: > https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-4.4/drivers/gpu/arm/midgard/mali_kbase_core_linux.c#4079 > >> It appears that your mali device driver's suspend/resume routines are >> accessing "struct devfreq_dev_status" directly. Is this correct? >> > no, but the suspend/resume would suspend/resume the governor. >> >> Plus, for MALI (if that assumption is correct), this issue might occur >> with other governors. >> >> If so, would it be better to put the first initializing call of >> devfreq_update_stats() at devfreq_add_device()? >> > right, that make sense. i put it here because the comment of this > function said it should be called by governor, but you're right, it > would be better this way, will send new version soon. >> >> Cheers, >> MyungJoo >> >> ps. Where can I look at the mali-devfreq device driver? (I couldn't >> find it) > sorry, i should mention that, please check above link :) >> >> >> >> >