From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Hilman Subject: Re: PM branch rebased to 2.6.29... for real this time Date: Thu, 02 Apr 2009 09:06:37 -0700 Message-ID: <49D4E28D.50601@deeprootsystems.com> References: <87k56dp5zc.fsf@deeprootsystems.com> <87ljqllzz9.fsf@deeprootsystems.com> <87bprgjjp4.fsf@deeprootsystems.com> <4d34a0a70904012058h62914304k3318720685b9513@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from wf-out-1314.google.com ([209.85.200.174]:33921 "EHLO wf-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762636AbZDBQGq (ORCPT ); Thu, 2 Apr 2009 12:06:46 -0400 Received: by wf-out-1314.google.com with SMTP id 29so710151wff.4 for ; Thu, 02 Apr 2009 09:06:44 -0700 (PDT) In-Reply-To: <4d34a0a70904012058h62914304k3318720685b9513@mail.gmail.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Kim Kyuwon Cc: "Premi, Sanjeev" , "linux-omap@vger.kernel.org" , "Nayak, Rajendra" Yes, this locking problem requires Rajendra's patchset which needs to be updated for the PM branch. Kevin Kim Kyuwon wrote: > Hi Kevin, Sanjeev, > > I'm having the same problem. > > when clk_set_rate() is invoked in omap_cpu_init() as shown below: > > clk_set_rate(mpu_clk, policy->cpuinfo.max_freq * 1000); > > It acquires the clocks mutex by the next statement. > > mutex_lock(&clocks_mutex); > > But after invoking arch_clock->clk_set_rate() in the middle of > clk_set_rate(), clock_set_rate() is invoked again. So deadlock occurs > due to mutex_lock() in clock_set_rate(). > > I think setting the default governor can not help this deadlock. > > Regards, > Kyuwon > > On Thu, Apr 2, 2009 at 3:46 AM, Kevin Hilman > wrote: >> "Premi, Sanjeev" writes: >> >> [...] >> >>>> Sounds to me like CPUfreq is changing frequencies during bootup. Did >>>> you select ondemand as the default CPUfreq governor? >>> [sp] Yes. This is what I feel too. Only I was not clear why the process >>> gets stuck at WFI. Haven't been able to debug further. So far... >>> >>>> If so, can you try with performance as the default governor. >>> [sp] It was performance governor only. >>> >>>> If you're already using performance, then u-boot is setting a slower >>>> speed and CPUfreq may decide to change it during boot. >>> [sp] That is the case. >>> >> Can you try setting the default governor to userspace so that no DVFS >> changes will happen during boot? >> >> Kevin >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-omap" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> > > >