From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 61E653328E0; Fri, 17 Oct 2025 15:23:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760714623; cv=none; b=i3vm0wXmmlA/yVxochhgZJpcFD1/+qUmWGsFlzz3GooFcthV8WPJFYFraDLEZtLDqLka0UQRlRDsMK0n6bFhX4yJGeROHuGqIMT9FzsYxc/JFRzIF4UouCfoijAP1y+oPxrPNXfD8px7r67AzUSIZLiniYag0ASqmaf+fjkIss0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760714623; c=relaxed/simple; bh=sUAilR0Y4gs6sC9vmg40+Wn8A1FFArDXY12EAtC3SMU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=XCTeXwuTw4AcG3d1Z5EAZBLXkdz6PLw3feyrYBnTSwuI1q4hcLX1+J8mwEmVbsBGHnYywfO1kgudLCnW+FykCH8pCFzNyF548sIg7nxNLI2Sg6U2gdbU/KK4jUA+m1KGMc9esjDRA527ks3YhgoUI2x/NFhJ4U2Q5H4qqnIqkYw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=U7QdNRTs; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="U7QdNRTs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8FC22C113D0; Fri, 17 Oct 2025 15:23:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760714622; bh=sUAilR0Y4gs6sC9vmg40+Wn8A1FFArDXY12EAtC3SMU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=U7QdNRTsQlfOMWE6gAnLpyp73dMci63NNz/Ft3H/qRRPiNeDnbXH2I3rZnWXWI7mG W+RoviIGuXmV427MfbZA7KML8rIKmYRJ2vYGRZV0UvCPzMWiWN4FTw0i8QfcW/+Jye 36g25efizHVIlfuKkjE2hvoNKQjFJL9dBTTMzjQk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Brian Norris , Brian Norris , Bjorn Helgaas Subject: [PATCH 6.12 177/277] PCI/sysfs: Ensure devices are powered for config reads Date: Fri, 17 Oct 2025 16:53:04 +0200 Message-ID: <20251017145153.591080535@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251017145147.138822285@linuxfoundation.org> References: <20251017145147.138822285@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Brian Norris commit 48991e4935078b05f80616c75d1ee2ea3ae18e58 upstream. The "max_link_width", "current_link_speed", "current_link_width", "secondary_bus_number", and "subordinate_bus_number" sysfs files all access config registers, but they don't check the runtime PM state. If the device is in D3cold or a parent bridge is suspended, we may see -EINVAL, bogus values, or worse, depending on implementation details. Wrap these access in pci_config_pm_runtime_{get,put}() like most of the rest of the similar sysfs attributes. Notably, "max_link_speed" does not access config registers; it returns a cached value since d2bd39c0456b ("PCI: Store all PCIe Supported Link Speeds"). Fixes: 56c1af4606f0 ("PCI: Add sysfs max_link_speed/width, current_link_speed/width, etc") Signed-off-by: Brian Norris Signed-off-by: Brian Norris Signed-off-by: Bjorn Helgaas Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20250924095711.v2.1.Ibb5b6ca1e2c059e04ec53140cd98a44f2684c668@changeid Signed-off-by: Greg Kroah-Hartman --- drivers/pci/pci-sysfs.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -200,8 +200,14 @@ static ssize_t max_link_width_show(struc struct device_attribute *attr, char *buf) { struct pci_dev *pdev = to_pci_dev(dev); + ssize_t ret; - return sysfs_emit(buf, "%u\n", pcie_get_width_cap(pdev)); + /* We read PCI_EXP_LNKCAP, so we need the device to be accessible. */ + pci_config_pm_runtime_get(pdev); + ret = sysfs_emit(buf, "%u\n", pcie_get_width_cap(pdev)); + pci_config_pm_runtime_put(pdev); + + return ret; } static DEVICE_ATTR_RO(max_link_width); @@ -213,7 +219,10 @@ static ssize_t current_link_speed_show(s int err; enum pci_bus_speed speed; + pci_config_pm_runtime_get(pci_dev); err = pcie_capability_read_word(pci_dev, PCI_EXP_LNKSTA, &linkstat); + pci_config_pm_runtime_put(pci_dev); + if (err) return -EINVAL; @@ -230,7 +239,10 @@ static ssize_t current_link_width_show(s u16 linkstat; int err; + pci_config_pm_runtime_get(pci_dev); err = pcie_capability_read_word(pci_dev, PCI_EXP_LNKSTA, &linkstat); + pci_config_pm_runtime_put(pci_dev); + if (err) return -EINVAL; @@ -246,7 +258,10 @@ static ssize_t secondary_bus_number_show u8 sec_bus; int err; + pci_config_pm_runtime_get(pci_dev); err = pci_read_config_byte(pci_dev, PCI_SECONDARY_BUS, &sec_bus); + pci_config_pm_runtime_put(pci_dev); + if (err) return -EINVAL; @@ -262,7 +277,10 @@ static ssize_t subordinate_bus_number_sh u8 sub_bus; int err; + pci_config_pm_runtime_get(pci_dev); err = pci_read_config_byte(pci_dev, PCI_SUBORDINATE_BUS, &sub_bus); + pci_config_pm_runtime_put(pci_dev); + if (err) return -EINVAL;