From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [PATCH 5/7] ARM: OMAP: dmtimer: Do not call PM runtime functions when not needed. Date: Fri, 10 Jun 2016 03:22:26 -0700 Message-ID: <20160610102225.GS22406@atomide.com> References: <1462634508-24961-1-git-send-email-ivo.g.dimitrov.75@gmail.com> <1462634508-24961-6-git-send-email-ivo.g.dimitrov.75@gmail.com> <20160509193624.GH5995@atomide.com> <5730F840.3050807@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <5730F840.3050807@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: Ivaylo Dimitrov Cc: robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, thierry.reding@gmail.com, bcousson@baylibre.com, linux@arm.linux.org.uk, mchehab@osg.samsung.com, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pwm@vger.kernel.org, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-media@vger.kernel.org, sre@kernel.org, pali.rohar@gmail.com List-Id: devicetree@vger.kernel.org * Ivaylo Dimitrov [160509 13:52]: > Hi, > > On 9.05.2016 22:36, Tony Lindgren wrote: > > * Ivaylo Dimitrov [160507 08:24]: > > > once omap_dm_timer_start() is called, which calls omap_dm_timer_enable() > > > and thus pm_runtime_get_sync(), it doesn't make sense to call PM runtime > > > functions again before omap_dm_timer_stop is called(). Otherwise PM runtime > > > functions called in omap_dm_timer_enable/disable lead to long and unneeded > > > delays. > > > > > > Fix that by implementing an "enabled" counter, so the PM runtime functions > > > get called only when really needed. > > > > > > Without that patch Nokia N900 IR TX driver (ir-rx51) does not function. > > > > Well, I just tested again, with the $subject patch reverted and > contradictory to my own words, it worked just fine. I believe the reason is > that I did hrtimer "migration" after I did the $subject patch. I was > thinking the reason for the slow transmission was PWM dmtimer, but now it > turns out it has been the "pulse" dmtimer. So, I think the $subject patch > should be dropped. > > > We should use pm_runtime for the refcounting though and call PM runtime > > unconditionally. Can you try to follow the standard PM runtime usage > > like this: > > > > It works without that, but on the other hand, I finally have some reference > on how PM runtime API should be called :). OK. And I just applied the related dts changes. Please repost the driver changes and DT binding doc with Rob's ack to the driver maintainers to apply. Regards, Tony