From nobody Mon Feb 9 15:07:27 2026 Received: from mail-wr1-f43.google.com (mail-wr1-f43.google.com [209.85.221.43]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8A4E315B0EB for ; Mon, 19 Aug 2024 08:24:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.43 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724055894; cv=none; b=C+l82WQV6NU0xynTTpoaoYRxKMiaOXmEeVFUmPRHOxfnJvtx4SnOFHdj3OCL7vtwzGTQfUNJbWNIh8/JbAEDEbzmbu8REx/GwlBVJrWsK0gt9KDbGisMqt2nj1ffkrpEjaxc272KE6OoEqoG97T981hlnuF8iQBTBff4Bs9+HLs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724055894; c=relaxed/simple; bh=VlEWS+I2qBUoAZu3MZiZFqikaq4uXZWuP6/ITJZxiQk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hQLQ77jcpDd9JbGJMi0SKo0oEyUwOz9mDBlRMYv0tZpVSPtVfDLWFaGClB/G3EjdIa1GxbBKrAM6HVUDawPzbSUiunl+uLfQbaLx2jWEeXNxeqMV0whjeILitcMZ/5nB+7SQ9Jpj4jEOo+e5kvh1UHBbFWKhfOHfVzFbjQkreHw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=bgdev.pl; spf=none smtp.mailfrom=bgdev.pl; dkim=pass (2048-bit key) header.d=bgdev-pl.20230601.gappssmtp.com header.i=@bgdev-pl.20230601.gappssmtp.com header.b=shwREonM; arc=none smtp.client-ip=209.85.221.43 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=bgdev.pl Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bgdev.pl Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bgdev-pl.20230601.gappssmtp.com header.i=@bgdev-pl.20230601.gappssmtp.com header.b="shwREonM" Received: by mail-wr1-f43.google.com with SMTP id ffacd0b85a97d-37195f88a17so1914873f8f.3 for ; Mon, 19 Aug 2024 01:24:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bgdev-pl.20230601.gappssmtp.com; s=20230601; t=1724055891; x=1724660691; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=Ns4EUZZ3nTL5odSKliuQhTwD1CbjvkOmQ7rToMzAA/s=; b=shwREonM23gbHLe1N7T/9wHhpCdWBD+QzoZnEleGkDhR0J78aNDGBmKUm1Atx69m/P cfVD/cbkLRwFV2INk70RfEeBYrd55Gxue8+7OOaBgTm+/yZWivSbW9IAlfSvJA1oQwFj wSk0/M6YuABQ9RKPCI2If9ExNunKh5YHkEznfEsXmXIBhSLnZ4CHwjzl/4S0TV0DyL8K +BQyK1uXCOW8r0WWC1GfIUF5o/ruiteOWjZWWOBA7JanC+ZGU+YYbZt+SVXrWX/CPxHH 5VZhHfE6cBz8OV85O39vZ2cpKAAMUeLMDng70ak/kC2sVCzHndIQhv36zkLSPvEa2a7o wWZQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1724055891; x=1724660691; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Ns4EUZZ3nTL5odSKliuQhTwD1CbjvkOmQ7rToMzAA/s=; b=rtSy4P1nawj8bKHhfr1Kld058wZdQ7DZm10cQyfmc0e3xNbmwzyfdu4t5aTw6V9TvL v9PxXIt5XfBXUBY+TKOMoMlq3qrP5iOPZOp7yO5/q/VzooNnP3IyifTB9a4HZ2BCMP40 CW3ju+0Ph8EVmdR0cm6slP/SHKG7sAcvzLL4XmcgnmQijU/zoQIFqWrJO88ADYeu68Y0 ZB2X4hQr/Aik7/S9X2OQasX8ITwDx+JJt9JADWiM7q0TFW26Q6MF1Mkecr2y+EHe1Gll 28scRFBJcd2EcBYLdCcJL54VfzQHm0zS0GYzMdtZHvamS+yqRflyiPKUxH7+9WZOSljI mEWw== X-Forwarded-Encrypted: i=1; AJvYcCW+RiVg42qk8cW2g7sDLCLQEd7B5i/R5jw/EdYqacVy5/bJIzWMrRxS54e0eRPPMLP/Mrs5zZycHoPA2NmH3c1qFeWIMsS74W1yb5bv X-Gm-Message-State: AOJu0Yzh+5PfOwnyAFbDX9hRlIR5WHVo4iC+6w8sqHQM+9ncXgFHLDNr tP3UtkY3LNUiDGsfkqU4ES6p93BYQLMZ2rkJpVQuI///TtTXEq4+ci+bsiK6C6M= X-Google-Smtp-Source: AGHT+IFVgF7niGJvoZowan0lPbSxtB3YSrW7+PmIqFLoVMhdafkr+QrJoILTdYPsvFiGEZpxfsdYjw== X-Received: by 2002:a5d:6602:0:b0:368:3194:8a85 with SMTP id ffacd0b85a97d-3719431769amr7258735f8f.7.1724055890365; Mon, 19 Aug 2024 01:24:50 -0700 (PDT) Received: from brgl-uxlite.home ([2a01:cb1d:dc:7e00:7b55:8f70:3ecb:b4ac]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-429ded7d5a9sm153441175e9.43.2024.08.19.01.24.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 19 Aug 2024 01:24:49 -0700 (PDT) From: Bartosz Golaszewski To: Bjorn Helgaas Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Bartosz Golaszewski , Konrad Dybcio Subject: [PATCH v2 2/2] PCI/pwrctl: put the bus rescan on a different thread Date: Mon, 19 Aug 2024 10:24:44 +0200 Message-ID: <20240819082445.10248-3-brgl@bgdev.pl> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240819082445.10248-1-brgl@bgdev.pl> References: <20240819082445.10248-1-brgl@bgdev.pl> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Bartosz Golaszewski If we trigger the bus rescan from sysfs, we'll try to lock the PCI rescan mutex recursively and deadlock - the platform device will be populated and probed on the same thread that handles the sysfs write. Add a workqueue to the pwrctl code on which we schedule the rescan for controlled PCI devices. While at it: add a new interface for initializing the pwrctl context where we'd now assign the parent device address and initialize the workqueue. Fixes: 4565d2652a37 ("PCI/pwrctl: Add PCI power control core code") Reported-by: Konrad Dybcio Signed-off-by: Bartosz Golaszewski --- drivers/pci/pwrctl/core.c | 26 +++++++++++++++++++++++--- drivers/pci/pwrctl/pci-pwrctl-pwrseq.c | 2 +- include/linux/pci-pwrctl.h | 3 +++ 3 files changed, 27 insertions(+), 4 deletions(-) diff --git a/drivers/pci/pwrctl/core.c b/drivers/pci/pwrctl/core.c index feca26ad2f6a..01d913b60316 100644 --- a/drivers/pci/pwrctl/core.c +++ b/drivers/pci/pwrctl/core.c @@ -48,6 +48,28 @@ static int pci_pwrctl_notify(struct notifier_block *nb, = unsigned long action, return NOTIFY_DONE; } =20 +static void rescan_work_func(struct work_struct *work) +{ + struct pci_pwrctl *pwrctl =3D container_of(work, struct pci_pwrctl, work); + + pci_lock_rescan_remove(); + pci_rescan_bus(to_pci_dev(pwrctl->dev->parent)->bus); + pci_unlock_rescan_remove(); +} + +/** + * pci_pwrctl_init() - Initialize the PCI power control context struct + * + * @pwrctl: PCI power control data + * @dev: Parent device + */ +void pci_pwrctl_init(struct pci_pwrctl *pwrctl, struct device *dev) +{ + pwrctl->dev =3D dev; + INIT_WORK(&pwrctl->work, rescan_work_func); +} +EXPORT_SYMBOL_GPL(pci_pwrctl_init); + /** * pci_pwrctl_device_set_ready() - Notify the pwrctl subsystem that the PCI * device is powered-up and ready to be detected. @@ -74,9 +96,7 @@ int pci_pwrctl_device_set_ready(struct pci_pwrctl *pwrctl) if (ret) return ret; =20 - pci_lock_rescan_remove(); - pci_rescan_bus(to_pci_dev(pwrctl->dev->parent)->bus); - pci_unlock_rescan_remove(); + schedule_work(&pwrctl->work); =20 return 0; } diff --git a/drivers/pci/pwrctl/pci-pwrctl-pwrseq.c b/drivers/pci/pwrctl/pc= i-pwrctl-pwrseq.c index c7a113a76c0c..f07758c9edad 100644 --- a/drivers/pci/pwrctl/pci-pwrctl-pwrseq.c +++ b/drivers/pci/pwrctl/pci-pwrctl-pwrseq.c @@ -50,7 +50,7 @@ static int pci_pwrctl_pwrseq_probe(struct platform_device= *pdev) if (ret) return ret; =20 - data->ctx.dev =3D dev; + pci_pwrctl_init(&data->ctx, dev); =20 ret =3D devm_pci_pwrctl_device_set_ready(dev, &data->ctx); if (ret) diff --git a/include/linux/pci-pwrctl.h b/include/linux/pci-pwrctl.h index 45e9cfe740e4..0d23dddf59ec 100644 --- a/include/linux/pci-pwrctl.h +++ b/include/linux/pci-pwrctl.h @@ -7,6 +7,7 @@ #define __PCI_PWRCTL_H__ =20 #include +#include =20 struct device; struct device_link; @@ -41,8 +42,10 @@ struct pci_pwrctl { /* Private: don't use. */ struct notifier_block nb; struct device_link *link; + struct work_struct work; }; =20 +void pci_pwrctl_init(struct pci_pwrctl *pwrctl, struct device *dev); int pci_pwrctl_device_set_ready(struct pci_pwrctl *pwrctl); void pci_pwrctl_device_unset_ready(struct pci_pwrctl *pwrctl); int devm_pci_pwrctl_device_set_ready(struct device *dev, --=20 2.43.0