From patchwork Thu Oct 22 08:52:44 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chen Yu X-Patchwork-Id: 11850605 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 31CA592C for ; Thu, 22 Oct 2020 08:50:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1B6D224196 for ; Thu, 22 Oct 2020 08:50:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2508535AbgJVIui (ORCPT ); Thu, 22 Oct 2020 04:50:38 -0400 Received: from mga02.intel.com ([134.134.136.20]:30334 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2508497AbgJVIui (ORCPT ); Thu, 22 Oct 2020 04:50:38 -0400 IronPort-SDR: UvAAUllRhEM831SIxhc+F4MLsjYhRrW/vpv6XKYULxpiHWZOtdgLBKas6MGPE0jW8SjX5K29m0 gbOOHYjihl0A== X-IronPort-AV: E=McAfee;i="6000,8403,9781"; a="154447989" X-IronPort-AV: E=Sophos;i="5.77,404,1596524400"; d="scan'208";a="154447989" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Oct 2020 01:50:37 -0700 IronPort-SDR: 5ZpNDfdJ6tu9t74RkPWecGI8aTOQuWNnicvSXQI2xssfu6SJgX68ueNh0t17URA95tdf7VjO9I OC5KdTQR6Y0Q== X-IronPort-AV: E=Sophos;i="5.77,404,1596524400"; d="scan'208";a="466609054" Received: from chenyu-office.sh.intel.com ([10.239.158.173]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Oct 2020 01:50:35 -0700 From: Chen Yu To: "Rafael J. Wysocki" , Len Brown , Greg Kroah-Hartman Cc: Andy Shevchenko , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Chen Yu Subject: [PATCH][v2] PM / sysfs: Expose suspend resume driver flags in sysfs Date: Thu, 22 Oct 2020 16:52:44 +0800 Message-Id: <20201022085244.1860-1-yu.c.chen@intel.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Currently there are 4 driver flags to control system suspend/resume behavior: DPM_FLAG_NO_DIRECT_COMPLETE, DPM_FLAG_SMART_PREPARE, DPM_FLAG_SMART_SUSPEND and DPM_FLAG_MAY_SKIP_RESUME. Make these flags visible in sysfs as read-only to get a brief understanding of the expected behavior of each device during suspend/resume, so as to facilitate suspend/resume debugging/tuning. For example: /sys/devices/pci0000:00/0000:00:15.1/power/driver_flags:4 (DPM_FLAG_SMART_SUSPEND) /sys/devices/pci0000:00/0000:00:07.3/power/driver_flags:5 (DPM_FLAG_NO_DIRECT_COMPLETE | DPM_FLAG_SMART_SUSPEND) Acked-by: Len Brown Signed-off-by: Chen Yu --- v2: Adding description in Documentation/ABI/testing/sysfs-devices-power according to Greg's suggestion. -- Documentation/ABI/testing/sysfs-devices-power | 11 +++++++ drivers/base/power/sysfs.c | 29 ++++++++++++++++++- 2 files changed, 39 insertions(+), 1 deletion(-) diff --git a/Documentation/ABI/testing/sysfs-devices-power b/Documentation/ABI/testing/sysfs-devices-power index 1763e64dd152..8ea68639ab3a 100644 --- a/Documentation/ABI/testing/sysfs-devices-power +++ b/Documentation/ABI/testing/sysfs-devices-power @@ -269,3 +269,14 @@ Description: the current runtime PM status of the device, which may be "suspended", "suspending", "resuming", "active", "error" (fatal error), or "unsupported" (runtime PM is disabled). + +What: /sys/devices/.../power/driver_flags +Date: October 2020 +Contact: Chen Yu +Description: + The /sys/devices/.../driver_flags attribute contains the driver + flags to control system suspend/resume. The flag is a combination + of DPM_FLAG_NO_DIRECT_COMPLETE, DPM_FLAG_SMART_PREPARE, + DPM_FLAG_SMART_SUSPEND and DPM_FLAG_MAY_SKIP_RESUME, or 0 if the + driver has not set any flag. This attribute is read-only. If + CONFIG_PM_ADVANCED_DEBUG is not set this attribute is empty. diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c index a1474fb67db9..48313a1040a5 100644 --- a/drivers/base/power/sysfs.c +++ b/drivers/base/power/sysfs.c @@ -607,6 +607,13 @@ static ssize_t async_store(struct device *dev, struct device_attribute *attr, static DEVICE_ATTR_RW(async); +static ssize_t driver_flags_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sysfs_emit(buf, "%x\n", dev->power.driver_flags); +} +static DEVICE_ATTR_RO(driver_flags); + #endif /* CONFIG_PM_SLEEP */ #endif /* CONFIG_PM_ADVANCED_DEBUG */ @@ -691,6 +698,20 @@ static const struct attribute_group pm_qos_flags_attr_group = { .attrs = pm_qos_flags_attrs, }; +static struct attribute *pm_driver_flags_attrs[] = { +#ifdef CONFIG_PM_ADVANCED_DEBUG +#ifdef CONFIG_PM_SLEEP + &dev_attr_driver_flags.attr, +#endif +#endif + NULL, +}; + +static const struct attribute_group pm_driver_flags_attr_group = { + .name = power_group_name, + .attrs = pm_driver_flags_attrs, +}; + int dpm_sysfs_add(struct device *dev) { int rc; @@ -719,11 +740,17 @@ int dpm_sysfs_add(struct device *dev) if (rc) goto err_wakeup; } - rc = pm_wakeup_source_sysfs_add(dev); + rc = sysfs_merge_group(&dev->kobj, &pm_driver_flags_attr_group); if (rc) goto err_latency; + + rc = pm_wakeup_source_sysfs_add(dev); + if (rc) + goto err_flags; return 0; + err_flags: + sysfs_unmerge_group(&dev->kobj, &pm_driver_flags_attr_group); err_latency: sysfs_unmerge_group(&dev->kobj, &pm_qos_latency_tolerance_attr_group); err_wakeup: