From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rajendra Nayak Subject: Re: [PATCHv3 8/9] ARM: OMAP3: prevent per_clkdm from attempting manual domain transitions Date: Thu, 12 Jul 2012 15:11:13 +0530 Message-ID: <4FFE9BB9.7000209@ti.com> References: <1338470942-20185-1-git-send-email-t-kristo@ti.com> <1338470942-20185-9-git-send-email-t-kristo@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from na3sys009aog124.obsmtp.com ([74.125.149.151]:36146 "EHLO na3sys009aog124.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757206Ab2GLJlU (ORCPT ); Thu, 12 Jul 2012 05:41:20 -0400 Received: by obqv19 with SMTP id v19so6701091obq.16 for ; Thu, 12 Jul 2012 02:41:19 -0700 (PDT) In-Reply-To: <1338470942-20185-9-git-send-email-t-kristo@ti.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Tero Kristo Cc: linux-omap@vger.kernel.org, khilman@ti.com, paul@pwsan.com, linux-arm-kernel@lists.infradead.org On Thursday 31 May 2012 06:59 PM, Tero Kristo wrote: > Previously, PER clock domain was always enabled, as the usecounts > for this domain incorrectly always showed positive value. On HW > level though, the domain enters idle as it is set in HW supervised > mode. Now, when the usecounts reflect real values, PER domain will > attempt to enter software supervised idle, which is not supported by the > hardware/kernel that well, and causes multiple problems. First of all, > coming back from idle, PER domain remains idle as the wakedeps have > been disabled for the domain, and this causes a crash with the GPIO > code, as the resume code attempts to access domain which is not active. > Just enabling the interface clocks for the GPIO does not help, as they > are autoidled and don't bring the domain out of idle. Secondly, there > are multiple erratas for omap3, which say that the wakedeps should be > enabled for the PER domain, see e.g. errata i582 for omap3630. If PER software supervised idle is so *buggy* then shouldn't the flags just reflect that PER *does not* support software supervised idle? Using a flag which reflects that the clkdm supports both hardware and software supervised idle ('CLKDM_CAN_HWSUP_SWSUP') and then using another one to actually skip putting it in software supervised sounds a little round about, no? Does updating the flag to 'CLKDM_CAN_HWSUP' also fix all the issues for you? without adding the additional 'CLKDM_SKIP_MANUAL_TRANS' flag. > > Signed-off-by: Tero Kristo > --- > arch/arm/mach-omap2/clockdomains3xxx_data.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/arch/arm/mach-omap2/clockdomains3xxx_data.c b/arch/arm/mach-omap2/clockdomains3xxx_data.c > index 6038adb..0dae4c8 100644 > --- a/arch/arm/mach-omap2/clockdomains3xxx_data.c > +++ b/arch/arm/mach-omap2/clockdomains3xxx_data.c > @@ -282,7 +282,7 @@ static struct clockdomain usbhost_clkdm = { > static struct clockdomain per_clkdm = { > .name = "per_clkdm", > .pwrdm = { .name = "per_pwrdm" }, > - .flags = CLKDM_CAN_HWSUP_SWSUP, > + .flags = CLKDM_CAN_HWSUP_SWSUP | CLKDM_SKIP_MANUAL_TRANS, > .dep_bit = OMAP3430_EN_PER_SHIFT, > .wkdep_srcs = per_wkdeps, > .sleepdep_srcs = per_sleepdeps,