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=-10.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 49CA1C433E9 for ; Thu, 3 Sep 2020 12:49:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1A10A2072A for ; Thu, 3 Sep 2020 12:49:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728902AbgICMtC (ORCPT ); Thu, 3 Sep 2020 08:49:02 -0400 Received: from mga17.intel.com ([192.55.52.151]:56721 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728986AbgICMsg (ORCPT ); Thu, 3 Sep 2020 08:48:36 -0400 IronPort-SDR: jOQMual3UjcANafx7/ZjsoNzQ5r8tD5UqZS0HGR7/36VGpxL2RALffDOuaMnjvVkKmaVC3BrAU zVblArJzxhmg== X-IronPort-AV: E=McAfee;i="6000,8403,9732"; a="137617081" X-IronPort-AV: E=Sophos;i="5.76,386,1592895600"; d="scan'208";a="137617081" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Sep 2020 05:48:23 -0700 IronPort-SDR: mh51FDKo99BE3cv0RW3w0m4s8JavAdmniQs7f/pZrNz9Tilv1Tn1ItIk2TVtjQCT2LF4jamd/Y 4TZLrcqY2j3A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.76,386,1592895600"; d="scan'208";a="331776973" Received: from smile.fi.intel.com (HELO smile) ([10.237.68.40]) by orsmga008.jf.intel.com with ESMTP; 03 Sep 2020 05:48:19 -0700 Received: from andy by smile with local (Exim 4.94) (envelope-from ) id 1kDof2-00E1pw-Qb; Thu, 03 Sep 2020 15:48:16 +0300 Date: Thu, 3 Sep 2020 15:48:16 +0300 From: Andy Shevchenko To: Hans de Goede Cc: Thierry Reding , Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Ville =?iso-8859-1?Q?Syrj=E4l=E4?= , "Rafael J . Wysocki" , Len Brown , linux-pwm@vger.kernel.org, intel-gfx , dri-devel@lists.freedesktop.org, Mika Westerberg , linux-acpi@vger.kernel.org Subject: Re: [PATCH v10 07/17] pwm: lpss: Remove suspend/resume handlers Message-ID: <20200903124816.GA1891694@smile.fi.intel.com> References: <20200903112337.4113-1-hdegoede@redhat.com> <20200903112337.4113-8-hdegoede@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200903112337.4113-8-hdegoede@redhat.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Sender: linux-pwm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pwm@vger.kernel.org On Thu, Sep 03, 2020 at 01:23:27PM +0200, Hans de Goede wrote: > PWM controller drivers should not restore the PWM state on resume. The > convention is that PWM consumers do this by calling pwm_apply_state(), > so that it can be done at the exact moment when the consumer needs > the state to be stored, avoiding e.g. backlight flickering. > > The only in kernel consumers of the pwm-lpss code, the i915 driver > and the pwm-class sysfs interface code both correctly restore the > state on resume, so there is no need to do this in the pwm-lpss code. > > More-over the removed resume handler is buggy, since it blindly > restores the ctrl-register contents without setting the update > bit, which is necessary to get the controller to actually use/apply > the restored base-unit and on-time-div values. While this is okay Reviewed-by: Andy Shevchenko the question is do we need to have similar in acpi_lpss.c? For example, static const struct lpss_device_desc byt_pwm_dev_desc = { .flags = LPSS_SAVE_CTX, ^^^^^^^^^^^^^^ .prv_offset = 0x800, .setup = byt_pwm_setup, }; static const struct lpss_device_desc bsw_pwm_dev_desc = { .flags = LPSS_SAVE_CTX | LPSS_NO_D3_DELAY, ^^^^^^^^^^^^^^ .prv_offset = 0x800, .setup = bsw_pwm_setup, }; > Acked-by: Thierry Reding > Signed-off-by: Hans de Goede > --- > Changes in v9: > - This is a new patch in v9 of this series > --- > drivers/pwm/pwm-lpss-platform.c | 1 - > drivers/pwm/pwm-lpss.c | 24 ------------------------ > drivers/pwm/pwm-lpss.h | 3 --- > 3 files changed, 28 deletions(-) > > diff --git a/drivers/pwm/pwm-lpss-platform.c b/drivers/pwm/pwm-lpss-platform.c > index 48f34d20aecd..c6502cf7a7af 100644 > --- a/drivers/pwm/pwm-lpss-platform.c > +++ b/drivers/pwm/pwm-lpss-platform.c > @@ -89,7 +89,6 @@ static int pwm_lpss_prepare(struct device *dev) > > static const struct dev_pm_ops pwm_lpss_platform_pm_ops = { > .prepare = pwm_lpss_prepare, > - SET_SYSTEM_SLEEP_PM_OPS(pwm_lpss_suspend, pwm_lpss_resume) > }; > > static const struct acpi_device_id pwm_lpss_acpi_match[] = { > diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c > index 9c5c7217c9b6..3444c56b4bed 100644 > --- a/drivers/pwm/pwm-lpss.c > +++ b/drivers/pwm/pwm-lpss.c > @@ -260,30 +260,6 @@ int pwm_lpss_remove(struct pwm_lpss_chip *lpwm) > } > EXPORT_SYMBOL_GPL(pwm_lpss_remove); > > -int pwm_lpss_suspend(struct device *dev) > -{ > - struct pwm_lpss_chip *lpwm = dev_get_drvdata(dev); > - int i; > - > - for (i = 0; i < lpwm->info->npwm; i++) > - lpwm->saved_ctrl[i] = readl(lpwm->regs + i * PWM_SIZE + PWM); > - > - return 0; > -} > -EXPORT_SYMBOL_GPL(pwm_lpss_suspend); > - > -int pwm_lpss_resume(struct device *dev) > -{ > - struct pwm_lpss_chip *lpwm = dev_get_drvdata(dev); > - int i; > - > - for (i = 0; i < lpwm->info->npwm; i++) > - writel(lpwm->saved_ctrl[i], lpwm->regs + i * PWM_SIZE + PWM); > - > - return 0; > -} > -EXPORT_SYMBOL_GPL(pwm_lpss_resume); > - > MODULE_DESCRIPTION("PWM driver for Intel LPSS"); > MODULE_AUTHOR("Mika Westerberg "); > MODULE_LICENSE("GPL v2"); > diff --git a/drivers/pwm/pwm-lpss.h b/drivers/pwm/pwm-lpss.h > index 7909fa12fca2..70db7e389d66 100644 > --- a/drivers/pwm/pwm-lpss.h > +++ b/drivers/pwm/pwm-lpss.h > @@ -19,7 +19,6 @@ struct pwm_lpss_chip { > struct pwm_chip chip; > void __iomem *regs; > const struct pwm_lpss_boardinfo *info; > - u32 saved_ctrl[MAX_PWMS]; > }; > > struct pwm_lpss_boardinfo { > @@ -37,7 +36,5 @@ struct pwm_lpss_boardinfo { > struct pwm_lpss_chip *pwm_lpss_probe(struct device *dev, struct resource *r, > const struct pwm_lpss_boardinfo *info); > int pwm_lpss_remove(struct pwm_lpss_chip *lpwm); > -int pwm_lpss_suspend(struct device *dev); > -int pwm_lpss_resume(struct device *dev); > > #endif /* __PWM_LPSS_H */ > -- > 2.28.0 > -- With Best Regards, Andy Shevchenko