From patchwork Fri Dec 8 19:20:00 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 752417 Received: from cloudserver094114.home.pl (cloudserver094114.home.pl [79.96.170.134]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4B70C10E7; Fri, 8 Dec 2023 11:20:45 -0800 (PST) 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 5.4.0) id 150833a18591e4b8; Fri, 8 Dec 2023 20:20:43 +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 9A3BF6688FC; Fri, 8 Dec 2023 20:20:42 +0100 (CET) From: "Rafael J. Wysocki" To: Linux PM Cc: Srinivas Pandruvada , Daniel Lezcano , Zhang Rui , Linux ACPI , LKML , Lukasz Luba Subject: [PATCH v1 3/3] thermal: core: Rework thermal zone availability check Date: Fri, 08 Dec 2023 20:20:00 +0100 Message-ID: <2258035.iZASKD2KPV@kreacher> In-Reply-To: <1880915.tdWV9SEqCh@kreacher> References: <1880915.tdWV9SEqCh@kreacher> Precedence: bulk X-Mailing-List: linux-pm@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: gggruggvucftvghtrhhoucdtuddrgedvkedrudekiedguddvgecutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfjqffogffrnfdpggftiffpkfenuceurghilhhouhhtmecuudehtdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhephffvvefufffkjghfggfgtgesthfuredttddtjeenucfhrhhomhepfdftrghfrggvlhculfdrucghhihsohgtkhhifdcuoehrjhifsehrjhifhihsohgtkhhirdhnvghtqeenucggtffrrghtthgvrhhnpedvffeuiedtgfdvtddugeeujedtffetteegfeekffdvfedttddtuefhgeefvdejhfenucfkphepudelhedrudefiedrudelrdelgeenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepihhnvghtpeduleehrddufeeirdduledrleegpdhhvghlohepkhhrvggrtghhvghrrdhlohgtrghlnhgvthdpmhgrihhlfhhrohhmpedftfgrfhgrvghlucflrdcuhgihshhotghkihdfuceorhhjfiesrhhjfiihshhotghkihdrnhgvtheqpdhnsggprhgtphhtthhopeejpdhrtghpthhtoheplhhinhhugidqphhmsehvghgvrhdrkhgvrhhnvghlrdhorhhgpdhrtghpthhtohepshhrihhnihhvrghsrdhprghnughruhhvrggurgeslhhinhhugidrihhnthgvlhdrtghomhdprhgtphhtthhopegurghnihgvlhdrlhgviigtrghnoheslhhinhgrrhhordhorhhgpdhrtghpthhtoheprhhuihdriihhrghnghesihhnthgvlhdrtghomhdprhgt phhtthhopehlihhnuhigqdgrtghpihesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhopehlihhnuhigqdhkvghrnhgvlhesvhhgvghrrdhkvghrnhgvlhdrohhrgh X-DCC--Metrics: v370.home.net.pl 1024; Body=7 Fuz1=7 Fuz2=7 From: Rafael J. Wysocki In order to avoid running __thermal_zone_device_update() for thermal zones going away, the thermal zone lock is held around device_del() in thermal_zone_device_unregister() and thermal_zone_device_update() passes the given thermal zone device to device_is_registered(). This allows thermal_zone_device_update() to skip the __thermal_zone_device_update() if device_del() has already run for the thermal zone at hand. However, instead of looking at driver core internals, the thermal subsystem may as well rely on its own data structures for this purpose. Namely, if the thermal zone is not present in thermal_tz_list, it can be regarded as unavailable, which in fact is already the case in thermal_zone_device_unregister(). Accordingly, the device_is_registered() check in thermal_zone_device_update() can be replaced with checking whether or not the node list_head in struct thermal_zone_device is empty, in which case it is not there in thermal_tz_list. To make this work, though, it is necessary to initialize tz->node in thermal_zone_device_register_with_trips() before registering the thermal zone device and it needs to be added to thermal_tz_list and deleted from it under its zone lock. After the above modifications, the zone lock does not need to be held around device_del() in thermal_zone_device_unregister() any more. Signed-off-by: Rafael J. Wysocki Acked-by: Daniel Lezcano --- drivers/thermal/thermal_core.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) Index: linux-pm/drivers/thermal/thermal_core.c =================================================================== --- linux-pm.orig/drivers/thermal/thermal_core.c +++ linux-pm/drivers/thermal/thermal_core.c @@ -505,11 +505,16 @@ int thermal_zone_device_is_enabled(struc return tz->mode == THERMAL_DEVICE_ENABLED; } +static bool thermal_zone_is_present(struct thermal_zone_device *tz) +{ + return !list_empty(&tz->node); +} + void thermal_zone_device_update(struct thermal_zone_device *tz, enum thermal_notify_event event) { mutex_lock(&tz->lock); - if (device_is_registered(&tz->device)) + if (thermal_zone_is_present(tz)) __thermal_zone_device_update(tz, event); mutex_unlock(&tz->lock); } @@ -1304,6 +1309,7 @@ thermal_zone_device_register_with_trips( } INIT_LIST_HEAD(&tz->thermal_instances); + INIT_LIST_HEAD(&tz->node); ida_init(&tz->ida); mutex_init(&tz->lock); init_completion(&tz->removal); @@ -1369,7 +1375,9 @@ thermal_zone_device_register_with_trips( } mutex_lock(&thermal_list_lock); + mutex_lock(&tz->lock); list_add_tail(&tz->node, &thermal_tz_list); + mutex_unlock(&tz->lock); mutex_unlock(&thermal_list_lock); /* Bind cooling devices for this zone */ @@ -1460,7 +1468,10 @@ void thermal_zone_device_unregister(stru mutex_unlock(&thermal_list_lock); return; } + + mutex_lock(&tz->lock); list_del(&tz->node); + mutex_unlock(&tz->lock); /* Unbind all cdevs associated with 'this' thermal zone */ list_for_each_entry(cdev, &thermal_cdev_list, node) @@ -1477,9 +1488,7 @@ void thermal_zone_device_unregister(stru ida_free(&thermal_tz_ida, tz->id); ida_destroy(&tz->ida); - mutex_lock(&tz->lock); device_del(&tz->device); - mutex_unlock(&tz->lock); kfree(tz->tzp);