From patchwork Mon Feb 17 20:14:19 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 866488 Received: from cloudserver094114.home.pl (cloudserver094114.home.pl [79.96.170.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 56C5C2376F9; Mon, 17 Feb 2025 20:20:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=79.96.170.134 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739823604; cv=none; b=NAAL/+5rsHHe0F+pHOLz6dMpS1/XTPoQrSSoeePzxPb/iSaikh4apwFrmPawNEMWq64n9aL/0qOAA+P1njzxXh5rwkBd5w2YnRVsy50X6xFFvws4En9A6xqKhjSAorTczHNHvY9uyqZrcIyo9T4PLdoGr4878d6w1FL66QNwF74= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739823604; c=relaxed/simple; bh=/iN7NRf7A6v8rajbgsWwV6unFpcBInCBdNQmcN5sn98=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=a44kHuHh139pDmTpvjgyWPdrf/KcB7BIX5E9gYYt+Tro4sOWlLx+kNmCXB792qVy8NssbtjmS9pFjWTUDpZyC74qAI9+OFQwkPXYR7HumB/8EfwTUWA4hGiFQzJYVib3ckj10NE0ch9WTkmoGmDIJW20g8qApJuuLTL+2m72KTs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=rjwysocki.net; spf=pass smtp.mailfrom=rjwysocki.net; dkim=pass (2048-bit key) header.d=rjwysocki.net header.i=@rjwysocki.net header.b=pdu7kBJX; arc=none smtp.client-ip=79.96.170.134 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=rjwysocki.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rjwysocki.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=rjwysocki.net header.i=@rjwysocki.net header.b="pdu7kBJX" Received: from localhost (127.0.0.1) (HELO v370.home.net.pl) by /usr/run/smtp (/usr/run/postfix/private/idea_relay_lmtp) via UNIX with SMTP (IdeaSmtpServer 6.2.1) id 4129ec6773cf2060; Mon, 17 Feb 2025 21:20:00 +0100 Received: from kreacher.localnet (unknown [195.136.19.94]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by cloudserver094114.home.pl (Postfix) with ESMTPSA id B76299100B0; Mon, 17 Feb 2025 21:19:59 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=rjwysocki.net; s=dkim; t=1739823600; bh=/iN7NRf7A6v8rajbgsWwV6unFpcBInCBdNQmcN5sn98=; h=From:Subject:Date; b=pdu7kBJXCAr60bE0mTtX8JmIksI/Ay4kXuBzLJVR4q7FMRgF3znZ5qbyayUkmTBat RIU5k6QATHm0HCwr+adXns9tLpdISN7Ql6PCnuruQylpsDEAFIUDtCWycc9bDf0GPq Bbfa3wnE1KMml+e5l8LjmiOAiC9+F//IOL7Ozz4f7EAIGyOWtlv2CKp/fUqVVwxhHN wVKZgcvci+5NN3QQ9Sct1jla+FSfV2MrLH9cjUhvLixKQHLsqjSq+Rv9KyRGllSt7d L/DqUjpuKXtIIQS7WNgSA2haWd0Sd+VJL4Qx8lohYDEMa3FiiOYMqoLpDykiUCV+Ls Hdn1eaIgSYAiw== From: "Rafael J. Wysocki" To: Linux PM Cc: LKML , Alan Stern , Bjorn Helgaas , Linux PCI , Ulf Hansson , Johan Hovold , Manivannan Sadhasivam , Jon Hunter , Linux ACPI , Mika Westerberg , Andy Shevchenko Subject: [PATCH v1 1/3] PM: Block enabling of runtime PM during system suspend Date: Mon, 17 Feb 2025 21:14:19 +0100 Message-ID: <2984234.e9J7NaK4W3@rjwysocki.net> In-Reply-To: <4966939.GXAFRqVoOG@rjwysocki.net> References: <4966939.GXAFRqVoOG@rjwysocki.net> Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CLIENT-IP: 195.136.19.94 X-CLIENT-HOSTNAME: 195.136.19.94 X-VADE-SPAMSTATE: clean X-VADE-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgeefvddrtddtgdehleefgecutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfjqffogffrnfdpggftiffpkfenuceurghilhhouhhtmecuudehtdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhephffvvefufffkjghfggfgtgesthfuredttddtjeenucfhrhhomhepfdftrghfrggvlhculfdrucghhihsohgtkhhifdcuoehrjhifsehrjhifhihsohgtkhhirdhnvghtqeenucggtffrrghtthgvrhhnpedvffeuiedtgfdvtddugeeujedtffetteegfeekffdvfedttddtuefhgeefvdejhfenucfkphepudelhedrudefiedrudelrdelgeenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepihhnvghtpeduleehrddufeeirdduledrleegpdhhvghlohepkhhrvggrtghhvghrrdhlohgtrghlnhgvthdpmhgrihhlfhhrohhmpehrjhifsehrjhifhihsohgtkhhirdhnvghtpdhnsggprhgtphhtthhopeduvddprhgtphhtthhopehlihhnuhigqdhpmhesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhopehlihhnuhigqdhkvghrnhgvlhesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhopehsthgvrhhnsehrohiflhgrnhgurdhhrghrvhgrrhgurdgvughupdhrtghpthhtohephhgvlhhgrggrsheskhgvrhhnvghlrdhorhhgpdhrtghpthhtoheplhhinhhugidqphgtihesvhhgvghrrdhkvghrnhgvlhdrohh X-DCC--Metrics: v370.home.net.pl 1024; Body=12 Fuz1=12 Fuz2=12 From: Rafael J. Wysocki If device_prepare() runs on a device that has never had runtime PM enabled so far, it may reasonably assume that runtime PM will not be enabled for that device during the system suspend-resume cycle currently in progress, but this has never been guaranteed. To verify this assumption, make device_prepare() arrange for triggering a device warning accompanied by a call trace dump if runtime PM is enabled for such a device after it has returned. Signed-off-by: Rafael J. Wysocki --- drivers/base/power/main.c | 9 +++++++++ drivers/base/power/runtime.c | 24 ++++++++++++++++++++++++ include/linux/pm.h | 1 + include/linux/pm_runtime.h | 6 +++++- 4 files changed, 39 insertions(+), 1 deletion(-) --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -1109,6 +1109,8 @@ device_unlock(dev); out: + /* If enabling runtime PM for the device is blocked, unblock it. */ + pm_runtime_unblock(dev); pm_runtime_put(dev); } @@ -1815,6 +1817,13 @@ * it again during the complete phase. */ pm_runtime_get_noresume(dev); + /* + * If runtime PM is disabled for the device at this point and it has + * never been enabled so far, it should not be enabled until this system + * suspend-resume cycle is complete, so prepare to trigger a warning on + * subsequent attempts to enable it. + */ + pm_runtime_block_if_disabled(dev); if (dev->power.syscore) return 0; --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -1460,6 +1460,26 @@ } EXPORT_SYMBOL_GPL(pm_runtime_barrier); +void pm_runtime_block_if_disabled(struct device *dev) +{ + spin_lock_irq(&dev->power.lock); + + if (dev->power.disable_depth && dev->power.last_status == RPM_INVALID) + dev->power.last_status = RPM_BLOCKED; + + spin_unlock_irq(&dev->power.lock); +} + +void pm_runtime_unblock(struct device *dev) +{ + spin_lock_irq(&dev->power.lock); + + if (dev->power.last_status == RPM_BLOCKED) + dev->power.last_status = RPM_INVALID; + + spin_unlock_irq(&dev->power.lock); +} + void __pm_runtime_disable(struct device *dev, bool check_resume) { spin_lock_irq(&dev->power.lock); @@ -1518,6 +1538,10 @@ if (--dev->power.disable_depth > 0) goto out; + if (dev->power.last_status == RPM_BLOCKED) { + dev_warn(dev, "Attempt to enabled runtime PM when it is blocked\n"); + dump_stack(); + } dev->power.last_status = RPM_INVALID; dev->power.accounting_timestamp = ktime_get_mono_fast_ns(); --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -597,6 +597,7 @@ RPM_RESUMING, RPM_SUSPENDED, RPM_SUSPENDING, + RPM_BLOCKED, }; /* --- a/include/linux/pm_runtime.h +++ b/include/linux/pm_runtime.h @@ -77,8 +77,10 @@ extern int pm_schedule_suspend(struct device *dev, unsigned int delay); extern int __pm_runtime_set_status(struct device *dev, unsigned int status); extern int pm_runtime_barrier(struct device *dev); +extern void pm_runtime_block_if_disabled(struct device *dev); +extern void pm_runtime_unblock(struct device *dev); extern void pm_runtime_enable(struct device *dev); -extern void __pm_runtime_disable(struct device *dev, bool check_resume); +extern void __pm_runtime_disable(struct device *dev, bool regular); extern void pm_runtime_allow(struct device *dev); extern void pm_runtime_forbid(struct device *dev); extern void pm_runtime_no_callbacks(struct device *dev); @@ -271,6 +273,8 @@ static inline int __pm_runtime_set_status(struct device *dev, unsigned int status) { return 0; } static inline int pm_runtime_barrier(struct device *dev) { return 0; } +static inline void pm_runtime_block_if_disabled(struct device *dev) {} +static inline void pm_runtime_unblock(struct device *dev) {} static inline void pm_runtime_enable(struct device *dev) {} static inline void __pm_runtime_disable(struct device *dev, bool c) {} static inline void pm_runtime_allow(struct device *dev) {} From patchwork Mon Feb 17 20:16:43 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 865981 Received: from cloudserver094114.home.pl (cloudserver094114.home.pl [79.96.170.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7A47D219A8A; Mon, 17 Feb 2025 20:20:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=79.96.170.134 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739823604; cv=none; b=F5hFKCM3B8PrI1jgZx1XHWbuz1msjy5DI/JWmKz76FmkMRD72hQH8yyeGWmnBIY6RK6GbEDdTV06/NK3Q5pFILvR0R7z0juM4IczgwGQ666RdXsklQHCdhV/zSVJ5dpsmLo/B1QeA1ckquQQHuRs608S+ZWxLkp1gFKrXoDGLno= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739823604; c=relaxed/simple; bh=VGPxZ+UZjJjw8SEv0KgowUz43qF+U/wYeXYgZBnh1kc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=MFTcSv3+HL7EPXxFvGrb+FesErgE+L5nrXOkRwWVyCApB88jEQxON/qlU4IMeyy0L/b3sZg5+SGRlLJBjes5adUkac3+YEzGC7SZtrVCwpcrLdCBB0PQ2BFqsYhKtHPesJ/nCKAczQ76491Q5vRCa0D2u9GC+3EK5swqf9iIO44= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=rjwysocki.net; spf=pass smtp.mailfrom=rjwysocki.net; dkim=pass (2048-bit key) header.d=rjwysocki.net header.i=@rjwysocki.net header.b=cpEFtdSX; arc=none smtp.client-ip=79.96.170.134 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=rjwysocki.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rjwysocki.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=rjwysocki.net header.i=@rjwysocki.net header.b="cpEFtdSX" Received: from localhost (127.0.0.1) (HELO v370.home.net.pl) by /usr/run/smtp (/usr/run/postfix/private/idea_relay_lmtp) via UNIX with SMTP (IdeaSmtpServer 6.2.1) id 2a51783161226919; Mon, 17 Feb 2025 21:19:59 +0100 Received: from kreacher.localnet (unknown [195.136.19.94]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by cloudserver094114.home.pl (Postfix) with ESMTPSA id D891A9100B0; Mon, 17 Feb 2025 21:19:58 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=rjwysocki.net; s=dkim; t=1739823599; bh=VGPxZ+UZjJjw8SEv0KgowUz43qF+U/wYeXYgZBnh1kc=; h=From:Subject:Date; b=cpEFtdSXfOtC8SqUKToccmhl9nwVkQvr2n9gMzI7Yl71Om8FHLEQ/n4hJU9hbaRBq pAy9eCqWwbRtmly/16tayNc8gYGDCq2GW/QH/nl7nnQ4QAr9BOl2XwaZNv6qTwRyRj VAIZVaysGNoHoNRFCbk2mKwZekQxzKf+ZUv4M1w72W7MV+u1KnI/UAv9Tq+i4TM+oM nQjw4/0qFm+nMRdc7cDn5bm5p8TNl1gipeQRwR6M8X1OfIt5NNcED/3o47uRT6ST08 8k9fg+SkbNjy2NvALALZKVH/hmX8iC/LHHjrO54G/iMlxHpEhErpQoovUDgM9lCWX5 Q9DGCfRPocqNQ== From: "Rafael J. Wysocki" To: Linux PM Cc: LKML , Alan Stern , Bjorn Helgaas , Linux PCI , Ulf Hansson , Johan Hovold , Manivannan Sadhasivam , Jon Hunter , Linux ACPI , Mika Westerberg , Andy Shevchenko Subject: [PATCH v1 2/3] PM: runtime: Introduce pm_runtime_blocked() Date: Mon, 17 Feb 2025 21:16:43 +0100 Message-ID: <8497121.T7Z3S40VBb@rjwysocki.net> In-Reply-To: <4966939.GXAFRqVoOG@rjwysocki.net> References: <4966939.GXAFRqVoOG@rjwysocki.net> Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CLIENT-IP: 195.136.19.94 X-CLIENT-HOSTNAME: 195.136.19.94 X-VADE-SPAMSTATE: clean X-VADE-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgeefvddrtddtgdehleefhecutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfjqffogffrnfdpggftiffpkfenuceurghilhhouhhtmecuudehtdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhephffvvefufffkjghfggfgtgesthfuredttddtjeenucfhrhhomhepfdftrghfrggvlhculfdrucghhihsohgtkhhifdcuoehrjhifsehrjhifhihsohgtkhhirdhnvghtqeenucggtffrrghtthgvrhhnpedvffeuiedtgfdvtddugeeujedtffetteegfeekffdvfedttddtuefhgeefvdejhfenucfkphepudelhedrudefiedrudelrdelgeenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepihhnvghtpeduleehrddufeeirdduledrleegpdhhvghlohepkhhrvggrtghhvghrrdhlohgtrghlnhgvthdpmhgrihhlfhhrohhmpehrjhifsehrjhifhihsohgtkhhirdhnvghtpdhnsggprhgtphhtthhopeduvddprhgtphhtthhopehlihhnuhigqdhpmhesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhopehlihhnuhigqdhkvghrnhgvlhesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhopehsthgvrhhnsehrohiflhgrnhgurdhhrghrvhgrrhgurdgvughupdhrtghpthhtohephhgvlhhgrggrsheskhgvrhhnvghlrdhorhhgpdhrtghpthhtoheplhhinhhugidqphgtihesvhhgvghrrdhkvghrnhgvlhdrohh X-DCC--Metrics: v370.home.net.pl 1024; Body=12 Fuz1=12 Fuz2=12 From: Rafael J. Wysocki Introduce a new helper function called pm_runtime_blocked() for checking the power.last_status value indicating whether or not the enabling of runtime PM for the given device has been blocked (which happens in the "prepare" phase of system-wide suspend if runtime PM is disabled for the given device at that point and has never been enabled so far). Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson --- drivers/base/power/runtime.c | 17 +++++++++++++++++ include/linux/pm_runtime.h | 2 ++ 2 files changed, 19 insertions(+) --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -1555,6 +1555,23 @@ } EXPORT_SYMBOL_GPL(pm_runtime_enable); +bool pm_runtime_blocked(struct device *dev) +{ + bool ret; + + /* + * dev->power.last_status is a bit field, so in case it is updated via + * RMW, read it under the spin lock. + */ + spin_lock_irq(&dev->power.lock); + + ret = dev->power.last_status == RPM_BLOCKED; + + spin_unlock_irq(&dev->power.lock); + + return ret; +} + static void pm_runtime_disable_action(void *data) { pm_runtime_dont_use_autosuspend(data); --- a/include/linux/pm_runtime.h +++ b/include/linux/pm_runtime.h @@ -81,6 +81,7 @@ extern void pm_runtime_unblock(struct device *dev); extern void pm_runtime_enable(struct device *dev); extern void __pm_runtime_disable(struct device *dev, bool regular); +extern bool pm_runtime_blocked(struct device *dev); extern void pm_runtime_allow(struct device *dev); extern void pm_runtime_forbid(struct device *dev); extern void pm_runtime_no_callbacks(struct device *dev); @@ -277,6 +278,7 @@ static inline void pm_runtime_unblock(struct device *dev) {} static inline void pm_runtime_enable(struct device *dev) {} static inline void __pm_runtime_disable(struct device *dev, bool c) {} +static inline bool pm_runtime_blocked(struct device *dev) { return true; } static inline void pm_runtime_allow(struct device *dev) {} static inline void pm_runtime_forbid(struct device *dev) {} From patchwork Mon Feb 17 20:19:41 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 866489 Received: from cloudserver094114.home.pl (cloudserver094114.home.pl [79.96.170.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8FB45149C41; Mon, 17 Feb 2025 20:20:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=79.96.170.134 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739823603; cv=none; b=OlH5I9R5T0jVEEViT6CEW+5Jufz31wnctjoMM6WO+bMGTNoWpvPPRRkxQq6dZMrx4HK3s187DT3sRrDtFZFSsSiTdFMjnOOMA6RmgxXnrqUPt5TdIQ6wqv3vZteKQVJjdufzZ3KVGOMY8Rkj85gbPML+GO6r+HLO4eufdw/vvwQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739823603; c=relaxed/simple; bh=/YPL+Qdj5nQduva774o+9werrMjy/VnTRhIWBdp51IY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=jW15XPLRUIctmAMhgvePBrj/Ra6oPUJSEAwayXmjdy6K61zG2ZsXn4Vh5N+PbuYAruToCjpQdgcCJBb716nn5sC0mWpdMJi66qdapR1dSKhdXP6VIrFMQdatyXzye//gx2ENqKJK6FFT637jITOLP5cNbXnXctTcAxS3mbySf4w= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=rjwysocki.net; spf=pass smtp.mailfrom=rjwysocki.net; dkim=pass (2048-bit key) header.d=rjwysocki.net header.i=@rjwysocki.net header.b=UgZAcIse; arc=none smtp.client-ip=79.96.170.134 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=rjwysocki.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rjwysocki.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=rjwysocki.net header.i=@rjwysocki.net header.b="UgZAcIse" Received: from localhost (127.0.0.1) (HELO v370.home.net.pl) by /usr/run/smtp (/usr/run/postfix/private/idea_relay_lmtp) via UNIX with SMTP (IdeaSmtpServer 6.2.1) id 2349e9a2f8523f5c; Mon, 17 Feb 2025 21:19:58 +0100 Received: from kreacher.localnet (unknown [195.136.19.94]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by cloudserver094114.home.pl (Postfix) with ESMTPSA id DD39E9100B0; Mon, 17 Feb 2025 21:19:57 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=rjwysocki.net; s=dkim; t=1739823598; bh=/YPL+Qdj5nQduva774o+9werrMjy/VnTRhIWBdp51IY=; h=From:Subject:Date; b=UgZAcIseRHmcvWA9lqNRWIUhtqmltkrpQElTb7JwiseKC00S1azy4uLecGc22JKbb T3i8v00K70VF9jCHNFfPE+zftOV9O9ArCJQEsVbz0TBVtugH3ehpF/nrGXZB+WcVv0 L75iqbrb2HIoJZD2ICtjivFnSAxdtpnb1veCpgfvHAhMH4x3iRZXrZeA0q0+3Sof6V /ojoIPzvpZ6yG/ZmNYMLcjl81W/viR8RJkjdZGQjOe+NYMksH9uBpwMfNA1xv0vf/x mnyH0KFdAUXQVZi1HRnJs9LjnyyhXrs+xpSZwWMFw+yB0GNNQKZFt3OkCSOoK6gx8C AiceuAiIL91mg== From: "Rafael J. Wysocki" To: Linux PM Cc: LKML , Alan Stern , Bjorn Helgaas , Linux PCI , Ulf Hansson , Johan Hovold , Manivannan Sadhasivam , Jon Hunter , Linux ACPI , Mika Westerberg , Andy Shevchenko Subject: [PATCH v1 3/3] PM: sleep: Use DPM_FLAG_SMART_SUSPEND conditionally Date: Mon, 17 Feb 2025 21:19:41 +0100 Message-ID: <2000822.PYKUYFuaPT@rjwysocki.net> In-Reply-To: <4966939.GXAFRqVoOG@rjwysocki.net> References: <4966939.GXAFRqVoOG@rjwysocki.net> Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CLIENT-IP: 195.136.19.94 X-CLIENT-HOSTNAME: 195.136.19.94 X-VADE-SPAMSTATE: clean X-VADE-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgeefvddrtddtgdehleefgecutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfjqffogffrnfdpggftiffpkfenuceurghilhhouhhtmecuudehtdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhephffvvefufffkjghfggfgtgesthfuredttddtjeenucfhrhhomhepfdftrghfrggvlhculfdrucghhihsohgtkhhifdcuoehrjhifsehrjhifhihsohgtkhhirdhnvghtqeenucggtffrrghtthgvrhhnpeefudduuedtuefgleffudeigeeitdeufeelvdejgefftdethffhhfethfeljefgteenucffohhmrghinhepkhgvrhhnvghlrdhorhhgnecukfhppeduleehrddufeeirdduledrleegnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehinhgvthepudelhedrudefiedrudelrdelgedphhgvlhhopehkrhgvrggthhgvrhdrlhhotggrlhhnvghtpdhmrghilhhfrhhomheprhhjfiesrhhjfiihshhotghkihdrnhgvthdpnhgspghrtghpthhtohepuddvpdhrtghpthhtoheplhhinhhugidqphhmsehvghgvrhdrkhgvrhhnvghlrdhorhhgpdhrtghpthhtoheplhhinhhugidqkhgvrhhnvghlsehvghgvrhdrkhgvrhhnvghlrdhorhhgpdhrtghpthhtohepshhtvghrnhesrhhofihlrghnugdrhhgrrhhvrghrugdrvgguuhdprhgtphhtthhopehhvghlghgrrghssehkvghrnhgvlhdrohhrghdprhgtphhtthhopehlihhnuhi X-DCC--Metrics: v370.home.net.pl 1024; Body=12 Fuz1=12 Fuz2=12 From: Rafael J. Wysocki A recent discussion has revealed that using DPM_FLAG_SMART_SUSPEND unconditionally is generally problematic because it may lead to situations in which the device's runtime PM information is internally inconsistent or does not reflect its real state [1]. For this reason, change the handling of DPM_FLAG_SMART_SUSPEND so that it is only taken into account if it is consistently set by the drivers of all devices having any PM callbacks throughout dependency graphs in accordance with the following rules: - The "smart suspend" feature is only enabled for devices whose drivers ask for it (that is, set DPM_FLAG_SMART_SUSPEND) and for devices without PM callbacks unless they have never had runtime PM enabled. - The "smart suspend" feature is not enabled for a device if it has not been enabled for the device's parent unless the parent does not take children into account or it has never had runtime PM enabled. - The "smart suspend" feature is not enabled for a device if it has not been enabled for one of the device's suppliers taking runtime PM into account unless that supplier has never had runtime PM enabled. Namely, introduce a new device PM flag called smart_suspend that is only set if the above conditions are met and update all DPM_FLAG_SMART_SUSPEND users to check power.smart_suspend instead of directly checking the latter. At the same time, drop the power.set_active flage introduced recently in commit 3775fc538f53 ("PM: sleep: core: Synchronize runtime PM status of parents and children") because it is now sufficient to check power.smart_suspend along with the dev_pm_skip_resume() return value to decide whether or not pm_runtime_set_active() needs to be called for the device. Link: https://lore.kernel.org/linux-pm/CAPDyKFroyU3YDSfw_Y6k3giVfajg3NQGwNWeteJWqpW29BojhQ@mail.gmail.com/ [1] Fixes: 7585946243d6 ("PM: sleep: core: Restrict power.set_active propagation") Signed-off-by: Rafael J. Wysocki --- drivers/acpi/device_pm.c | 6 +--- drivers/base/power/main.c | 63 +++++++++++++++++++++++++++++++++++----------- drivers/mfd/intel-lpss.c | 2 - drivers/pci/pci-driver.c | 6 +--- include/linux/pm.h | 2 - 5 files changed, 55 insertions(+), 24 deletions(-) --- a/drivers/acpi/device_pm.c +++ b/drivers/acpi/device_pm.c @@ -1161,8 +1161,7 @@ */ int acpi_subsys_suspend(struct device *dev) { - if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) || - acpi_dev_needs_resume(dev, ACPI_COMPANION(dev))) + if (!dev->power.smart_suspend || acpi_dev_needs_resume(dev, ACPI_COMPANION(dev))) pm_runtime_resume(dev); return pm_generic_suspend(dev); @@ -1320,8 +1319,7 @@ */ int acpi_subsys_poweroff(struct device *dev) { - if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) || - acpi_dev_needs_resume(dev, ACPI_COMPANION(dev))) + if (!dev->power.smart_suspend || acpi_dev_needs_resume(dev, ACPI_COMPANION(dev))) pm_runtime_resume(dev); return pm_generic_poweroff(dev); --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -656,15 +656,13 @@ * so change its status accordingly. * * Otherwise, the device is going to be resumed, so set its PM-runtime - * status to "active" unless its power.set_active flag is clear, in + * status to "active" unless its power.smart_suspend flag is clear, in * which case it is not necessary to update its PM-runtime status. */ - if (skip_resume) { + if (skip_resume) pm_runtime_set_suspended(dev); - } else if (dev->power.set_active) { + else if (dev->power.smart_suspend) pm_runtime_set_active(dev); - dev->power.set_active = false; - } if (dev->pm_domain) { info = "noirq power domain "; @@ -1282,14 +1280,8 @@ dev->power.may_skip_resume)) dev->power.must_resume = true; - if (dev->power.must_resume) { - if (dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND)) { - dev->power.set_active = true; - if (dev->parent && !dev->parent->power.ignore_children) - dev->parent->power.set_active = true; - } + if (dev->power.must_resume) dpm_superior_set_must_resume(dev); - } Complete: complete_all(&dev->power.completion); @@ -1797,6 +1789,49 @@ return error; } +static void device_prepare_smart_suspend(struct device *dev) +{ + struct device_link *link; + int idx; + + /* + * The "smart suspend" feature is enabled for devices whose drivers ask + * for it and for devices without PM callbacks unless runtime PM is + * disabled and enabling it is blocked for them. + * + * However, if "smart suspend" is not enabled for the device's parent + * or any of its suppliers that take runtime PM into account, it cannot + * be enabled for the device either. + */ + dev->power.smart_suspend = (dev->power.no_pm_callbacks || + dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND)) && + !pm_runtime_blocked(dev); + + if (!dev->power.smart_suspend) + return; + + if (dev->parent && !pm_runtime_blocked(dev->parent) && + !dev->parent->power.ignore_children && !dev->parent->power.smart_suspend) { + dev->power.smart_suspend = false; + return; + } + + idx = device_links_read_lock(); + + list_for_each_entry_rcu_locked(link, &dev->links.suppliers, c_node) { + if (!(link->flags | DL_FLAG_PM_RUNTIME)) + continue; + + if (!pm_runtime_blocked(link->supplier) && + !link->supplier->power.smart_suspend) { + dev->power.smart_suspend = false; + break; + } + } + + device_links_read_unlock(idx); +} + /** * device_prepare - Prepare a device for system power transition. * @dev: Device to handle. @@ -1858,6 +1893,7 @@ pm_runtime_put(dev); return ret; } + device_prepare_smart_suspend(dev); /* * A positive return value from ->prepare() means "this device appears * to be runtime-suspended and its state is fine, so if it really is @@ -2033,6 +2069,5 @@ bool dev_pm_skip_suspend(struct device *dev) { - return dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) && - pm_runtime_status_suspended(dev); + return dev->power.smart_suspend && pm_runtime_status_suspended(dev); } --- a/drivers/mfd/intel-lpss.c +++ b/drivers/mfd/intel-lpss.c @@ -480,7 +480,7 @@ static int resume_lpss_device(struct device *dev, void *data) { - if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND)) + if (!dev->power.smart_suspend) pm_runtime_resume(dev); return 0; --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -812,8 +812,7 @@ * suspend callbacks can cope with runtime-suspended devices, it is * better to resume the device from runtime suspend here. */ - if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) || - pci_dev_need_resume(pci_dev)) { + if (!dev->power.smart_suspend || pci_dev_need_resume(pci_dev)) { pm_runtime_resume(dev); pci_dev->state_saved = false; } else { @@ -1151,8 +1150,7 @@ } /* The reason to do that is the same as in pci_pm_suspend(). */ - if (!dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) || - pci_dev_need_resume(pci_dev)) { + if (!dev->power.smart_suspend || pci_dev_need_resume(pci_dev)) { pm_runtime_resume(dev); pci_dev->state_saved = false; } else { --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -680,8 +680,8 @@ bool syscore:1; bool no_pm_callbacks:1; /* Owned by the PM core */ bool async_in_progress:1; /* Owned by the PM core */ + bool smart_suspend:1; /* Owned by the PM core */ bool must_resume:1; /* Owned by the PM core */ - bool set_active:1; /* Owned by the PM core */ bool may_skip_resume:1; /* Set by subsystems */ #else bool should_wakeup:1;