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 F372927466A for ; Mon, 20 Oct 2025 16:25:23 +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=1760977524; cv=none; b=Gv4qVnmiDjI5fSbxwh1iWBoT/xyvauKPqUN9SMf/IOMxx4oXxTLEoBVeNpiGan6yKFJjuijzyIvi1z11RFvzrsnCDQ4jkHGvzcSvtB+Lz/44teYtUooVAWE/raSVyqn5Sq44nOK2pBI0Gh1I5rg1Fd2GgPrVRrtsdEGljBVIoes= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760977524; c=relaxed/simple; bh=O2PrlYDyUooiK8UpoOGsPil7+hJ+QMSy0ELV1OdP3DE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=gQPjzjlRa5R8xl+gCJIoHrdVkzyDloJpykFeir9jmBrV02OG1kRVGXtNQn+bY67yW2GvwkanyTg8q/7QpOS+NcZttXc24HZ58k3jcw/n8WJGjKCKsn035UJeLOXhsiDqkUnlbfPS0LVrKZ2QJ4GZasm8HnY56Ft/pzkiEFzrwlk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Ylmb8gcm; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Ylmb8gcm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D938CC4CEFE; Mon, 20 Oct 2025 16:25:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1760977523; bh=O2PrlYDyUooiK8UpoOGsPil7+hJ+QMSy0ELV1OdP3DE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ylmb8gcmeKLpMkQ1g0EaY+ltdDpJJxlBCAqunkPnp6D3GJlSV6AViQomMmUw3Kqbz d9j8DsZ/FNL39ro/aHNVsVsEmc9rQoFwO7fSpkBRcKH/qAW4R5mFXPm9Wm1MU7/NVj t/uzVb3rKQ7Pz4M3yNc/0kWAPxKPPNk3AsmU7WqqX29NdCIuSmwRqvghRmN3JaZMQQ M9Ty4RGM2TVrAB6i6klwhsNUW7d8T4lZMapmLEYUDWfUIATGtd0qVMDXr3CxgUKG83 Szm5sH/6lwZFlDpE/LbS50xhJDy4gKNGAoy4FX/QBz163wheWr0pprHtuUS7U5xFrX b9rXkaUAAn1RA== From: Sasha Levin To: stable@vger.kernel.org Cc: Brian Norris , Brian Norris , Bjorn Helgaas , Sasha Levin Subject: [PATCH 5.10.y 3/3] PCI/sysfs: Ensure devices are powered for config reads Date: Mon, 20 Oct 2025 12:25:18 -0400 Message-ID: <20251020162518.1838256-3-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251020162518.1838256-1-sashal@kernel.org> References: <2025101636-tartar-brethren-067c@gregkh> <20251020162518.1838256-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Brian Norris [ Upstream commit 48991e4935078b05f80616c75d1ee2ea3ae18e58 ] 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: Sasha Levin --- drivers/pci/pci-sysfs.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 3fddd421bbe66..651887d36368c 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -174,8 +174,14 @@ static ssize_t max_link_width_show(struct device *dev, 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); @@ -187,7 +193,10 @@ static ssize_t current_link_speed_show(struct device *dev, 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; @@ -204,7 +213,10 @@ static ssize_t current_link_width_show(struct device *dev, 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; @@ -221,7 +233,10 @@ static ssize_t secondary_bus_number_show(struct device *dev, 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; @@ -237,7 +252,10 @@ static ssize_t subordinate_bus_number_show(struct device *dev, 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; -- 2.51.0