From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 76975C10DCE for ; Fri, 6 Mar 2020 18:14:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4A65D20578 for ; Fri, 6 Mar 2020 18:14:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726237AbgCFSOr (ORCPT ); Fri, 6 Mar 2020 13:14:47 -0500 Received: from muru.com ([72.249.23.125]:59204 "EHLO muru.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726194AbgCFSOr (ORCPT ); Fri, 6 Mar 2020 13:14:47 -0500 Received: from atomide.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTPS id D761D8027; Fri, 6 Mar 2020 18:15:31 +0000 (UTC) Date: Fri, 6 Mar 2020 10:14:43 -0800 From: Tony Lindgren To: Lokesh Vutla Cc: Thierry Reding , Uwe =?utf-8?Q?Kleine-K=C3=B6nig?= , Linux OMAP Mailing List , linux-kernel@vger.kernel.org, linux-pwm@vger.kernel.org, Sekhar Nori , Vignesh R , Sebastian Reichel Subject: Re: [PATCH v2 4/6] pwm: omap-dmtimer: Fix pwm disabling sequence Message-ID: <20200306181443.GJ37466@atomide.com> References: <20200228095651.32464-1-lokeshvutla@ti.com> <20200228095651.32464-5-lokeshvutla@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200228095651.32464-5-lokeshvutla@ti.com> Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org * Lokesh Vutla [200228 09:58]: > pwm_omap_dmtimer_disable() calls .stop callback which abruptly stops the > timer counter. This doesn't complete the current pwm cycle and > immediately disables the pwm. Instead disable the auto reload > functionality which allows to complete the current pwm cycle and then > disables the timer. > > Signed-off-by: Lokesh Vutla > --- > drivers/pwm/pwm-omap-dmtimer.c | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > diff --git a/drivers/pwm/pwm-omap-dmtimer.c b/drivers/pwm/pwm-omap-dmtimer.c > index bc338619232d..89b3c25d02b8 100644 > --- a/drivers/pwm/pwm-omap-dmtimer.c > +++ b/drivers/pwm/pwm-omap-dmtimer.c > @@ -93,8 +93,16 @@ static void pwm_omap_dmtimer_disable(struct pwm_chip *chip, > { > struct pwm_omap_dmtimer_chip *omap = to_pwm_omap_dmtimer_chip(chip); > > + /* > + * Disable auto reload so that the current cycle gets completed and > + * then the counter stops. > + */ > mutex_lock(&omap->mutex); > - omap->pdata->stop(omap->dm_timer); > + omap->pdata->set_pwm(omap->dm_timer, > + pwm_get_polarity(pwm) == PWM_POLARITY_INVERSED, > + true, OMAP_TIMER_TRIGGER_OVERFLOW_AND_COMPARE, > + false); > + > mutex_unlock(&omap->mutex); > } I'm seeing an issue with this patch where after use something is left on and power consumption stays higher by about 30 mW after use. I can reproduce this easily on droid4 with Sebastian's rumble-test app[0]. After use, I sometimes also hear the vibrator keep chirping quietly, so there seems to be some pwm still happening after disable :) Reloading modules for pwm-vibra and pwm-omap-dmtimer make the power consumption go back down again. If you have a scope set up, maybe check the lines are quiet after disable after this patch? Regards, Tony [0] https://git.collabora.com/cgit/user/sre/rumble-test.git/plain/rumble-test.c