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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 78F2EC4332F for ; Fri, 8 Oct 2021 14:44:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4ECDD61038 for ; Fri, 8 Oct 2021 14:44:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242602AbhJHOqE (ORCPT ); Fri, 8 Oct 2021 10:46:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50456 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242577AbhJHOqD (ORCPT ); Fri, 8 Oct 2021 10:46:03 -0400 Received: from mail-lf1-x134.google.com (mail-lf1-x134.google.com [IPv6:2a00:1450:4864:20::134]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3776CC061762 for ; Fri, 8 Oct 2021 07:44:08 -0700 (PDT) Received: by mail-lf1-x134.google.com with SMTP id x27so40184603lfa.9 for ; Fri, 08 Oct 2021 07:44:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=FTJ2jzOfmc3TfTGxqKqcv2O3a+phTUEvAqWV0+MH2I8=; b=s53m6uBMCKLVuMai6xOkjXRWzjdBLDWO9V6TCYwEVJt2137PhtrSymyhoMDNpkbBTN dTkXP50Zihn4E6SNLs1NBxsimctK1QYxpfOVPuzNH/MjjM6cDlAhFZtgB/8IDdftxwku 5CUbrSpqPYl1GyJKo4VhKPUGQVBKubfvlReegWA+A7s3/v2CyUuaxeNs+GqZodeeJZgV m84zRvKn33o1ImOZ8uW2+2o9/o52yr5WEicoFX16v/w4zSsw5LwfY2PXV52S0ceL5Y9v zinQG5YgDeMEheB4ZV3tpNB1oQ3Iv6TLky7A5Nq7vC4bnBwQnXWN0LZm78hR4k5S6/ue G7Jw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=FTJ2jzOfmc3TfTGxqKqcv2O3a+phTUEvAqWV0+MH2I8=; b=ch2Rp/9R08zJXpHJ/H7/CWGbvHxk+zWhfzpPkJlBpFwAZ34dN1dYauRWkN4y65HfLP 9ZAp5bjd30y1sSMdnj4n6oZ8hRclu3eUaPamwgY3rvEqZgnXK2RWSp6w2OFzYoa+wFT6 qnifzhkYp1IiE15+5eRzIJuiomg4s9V6Hy9+UVoLNBs/SPO3iVKTOtj4R0btvR0hNh4o HbOYo+hHVdtwtRuIJQ6ScJVhKvFBD/Z8Mn5IftjqPya2v2womPXi1Bmm8y+aNSWYvEUr 1QIycLVeOd9/JsJtCaScTWE1kJDQ05qKYUXIxo33uHWTr2UOzJYijeMwchBcGg5IMtuM GsuA== X-Gm-Message-State: AOAM531NKy/gpABq9CsbTOVmHn+6EeRhbmp10ZzrcIcHvS2e+9siUkqJ s6MyccMs5TyiLqksRGQ1xfhxnGm7MU4AmjDUL2fPvg== X-Google-Smtp-Source: ABdhPJzO67ce7CZQmVwkFnv5byVeOw9GUdg20sd6cp27QaBH2EPeuuev9vaX1QT+7hshqASQHLuGWvTJLwml3zHz5tY= X-Received: by 2002:a19:6a16:: with SMTP id u22mr10587977lfu.254.1633704245995; Fri, 08 Oct 2021 07:44:05 -0700 (PDT) MIME-Version: 1.0 References: <20210930065733.31943-1-tony@atomide.com> <20210930065733.31943-5-tony@atomide.com> In-Reply-To: <20210930065733.31943-5-tony@atomide.com> From: Ulf Hansson Date: Fri, 8 Oct 2021 16:43:29 +0200 Message-ID: Subject: Re: [PATCH 4/5] mmc: sdhci-omap: Implement PM runtime functions To: Tony Lindgren Cc: Adrian Hunter , Chunyan Zhang , Faiz Abbas , Kishon Vijay Abraham I , Santosh Shilimkar , linux-mmc , linux-omap , Rob Herring , DTML Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org On Thu, 30 Sept 2021 at 08:57, Tony Lindgren wrote: > > Implement PM runtime functions and enable MMC_CAP_AGGRESSIVE_PM. I suggest you split this change into two pieces. MMC_CAP_AGGRESSIVE_PM is about enabling runtime PM management for the eMMC/SD card device, which is perfectly fine to use independently of whether runtime PM is supported for the host device. > > Note that we save context in probe to avoid restoring invalid context > on the first resume. For system suspend, we have the new PM runtime > functions do most of the work. > > Signed-off-by: Tony Lindgren > --- > drivers/mmc/host/sdhci-omap.c | 66 +++++++++++++++++++++++++++++------ > 1 file changed, 56 insertions(+), 10 deletions(-) > > diff --git a/drivers/mmc/host/sdhci-omap.c b/drivers/mmc/host/sdhci-omap.c > --- a/drivers/mmc/host/sdhci-omap.c > +++ b/drivers/mmc/host/sdhci-omap.c > @@ -117,6 +117,9 @@ struct sdhci_omap_host { > > struct pinctrl *pinctrl; > struct pinctrl_state **pinctrl_state; > + unsigned long context_valid:1; > + unsigned long is_runtime_suspended:1; > + unsigned long needs_resume:1; > bool is_tuning; > > /* Offset for omap specific registers from base */ > @@ -1207,6 +1210,8 @@ static const struct soc_device_attribute sdhci_omap_soc_devices[] = { > } > }; > > +static void sdhci_omap_context_save(struct sdhci_omap_host *omap_host); > + > static int sdhci_omap_probe(struct platform_device *pdev) > { > int ret; > @@ -1338,6 +1343,8 @@ static int sdhci_omap_probe(struct platform_device *pdev) > /* R1B responses is required to properly manage HW busy detection. */ > mmc->caps |= MMC_CAP_NEED_RSP_BUSY; > > + mmc->caps |= MMC_CAP_AGGRESSIVE_PM; > + > ret = sdhci_setup_host(host); > if (ret) > goto err_put_sync; > @@ -1350,6 +1357,11 @@ static int sdhci_omap_probe(struct platform_device *pdev) > if (ret) > goto err_cleanup_host; > > + sdhci_omap_context_save(omap_host); > + omap_host->context_valid = 1; Looks like you can remove this flag, it's not being used. > + > + pm_runtime_put_sync(dev); I recommend to use the PM runtime autosuspend feature, as to avoid an initial latency for every I/O request to the host driver. The mmc core already supports that, see mmc_release_host(). The typical default timeout value for autosuspend, is usually set ~50-200ms, by host drivers (if I recall correctly). > + > return 0; > > err_cleanup_host: > @@ -1371,6 +1383,7 @@ static int sdhci_omap_remove(struct platform_device *pdev) > struct device *dev = &pdev->dev; > struct sdhci_host *host = platform_get_drvdata(pdev); > > + pm_runtime_get_sync(dev); > sdhci_remove_host(host, true); > pm_runtime_put_sync(dev); There is no guarantee that this triggers a call to ->sdhci_omap_runtime_suspend(), which I guess is what we want. Userspace via sysfs may have increase the RPM usage count (pm_runtime_forbid(), for example. To address this, I would call pm_runtime_disable() first and then explicitly put the device into low power state, rather than relying on runtime PM to do it. Another option could be to use pm_runtime_force_suspend(). > pm_runtime_disable(dev); > @@ -1402,42 +1415,75 @@ static void sdhci_omap_context_restore(struct sdhci_omap_host *omap_host) > sdhci_omap_writel(omap_host, SDHCI_OMAP_ISE, omap_host->ise); > } > > -static int __maybe_unused sdhci_omap_suspend(struct device *dev) > +static int __maybe_unused sdhci_omap_runtime_suspend(struct device *dev) > { > struct sdhci_host *host = dev_get_drvdata(dev); > struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); > struct sdhci_omap_host *omap_host = sdhci_pltfm_priv(pltfm_host); > > - sdhci_suspend_host(host); > - Shouldn't you call sdhci_runtime_suspend_host() somewhere here? > sdhci_omap_context_save(omap_host); > > pinctrl_pm_select_idle_state(dev); > > - pm_runtime_force_suspend(dev); > + omap_host->is_runtime_suspended = 1; > > return 0; > } > > -static int __maybe_unused sdhci_omap_resume(struct device *dev) > +static int __maybe_unused sdhci_omap_runtime_resume(struct device *dev) > { > struct sdhci_host *host = dev_get_drvdata(dev); > struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); > struct sdhci_omap_host *omap_host = sdhci_pltfm_priv(pltfm_host); > > - pm_runtime_force_resume(dev); > - > pinctrl_pm_select_default_state(dev); > > - sdhci_omap_context_restore(omap_host); > + if (omap_host->context_valid) > + sdhci_omap_context_restore(omap_host); > + > + omap_host->is_runtime_suspended = 0; Shouldn't you call sdhci_runtime_resume_host() somewhere here? > + > + return 0; > +} > + > +static int __maybe_unused sdhci_omap_suspend(struct device *dev) > +{ > + struct sdhci_host *host = dev_get_drvdata(dev); > + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); > + struct sdhci_omap_host *omap_host = sdhci_pltfm_priv(pltfm_host); > + > + if (omap_host->is_runtime_suspended) > + return 0; So if the host is already runtime suspended, it's okay to just leave it as is? In a way that sounds like you could call pm_runtime_force_suspend() instead, assuming the sdhci_omap_runtime_suspend() can be extended to do the right thing for system suspend as well. It looks a bit odd that sdhci_suspend_host() is called only when the host is runtime resumed. Perhaps you can elaborate a bit more on why this is, so I can understand better what you want to achieve here. > + > + sdhci_suspend_host(host); > + sdhci_omap_runtime_suspend(dev); > + omap_host->needs_resume = 1; > > + return 0; > +} > + > +static int __maybe_unused sdhci_omap_resume(struct device *dev) > +{ > + struct sdhci_host *host = dev_get_drvdata(dev); > + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host); > + struct sdhci_omap_host *omap_host = sdhci_pltfm_priv(pltfm_host); > + > + if (!omap_host->needs_resume) > + return 0; > + > + sdhci_omap_runtime_resume(dev); > sdhci_resume_host(host); > + omap_host->needs_resume = 0; > > return 0; > } > #endif > -static SIMPLE_DEV_PM_OPS(sdhci_omap_dev_pm_ops, sdhci_omap_suspend, > - sdhci_omap_resume); > + > +static const struct dev_pm_ops sdhci_omap_dev_pm_ops = { > + SET_RUNTIME_PM_OPS(sdhci_omap_runtime_suspend, > + sdhci_omap_runtime_resume, NULL) > + SET_SYSTEM_SLEEP_PM_OPS(sdhci_omap_suspend, sdhci_omap_resume) > +}; > > static struct platform_driver sdhci_omap_driver = { > .probe = sdhci_omap_probe, > -- > 2.33.0 Kind regards Uffe