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 E465531B83D; Mon, 27 Oct 2025 19:02:46 +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=1761591767; cv=none; b=s8G8gHGpGmIupf2/Rqf0C3PB7ILJUuLKXX00wmmyTSDipa2Y86a4ZvbhdkDueoqDV5s+8R66VPRXe22dEX9njq8mAWpcWoTEyMc2MxRAzeCiMFvu8TBv6iEm0t4O+UfjB2NKdpVARBBqGpG+FUuq5EDm9tkkocwPnvKc8c+zX5E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761591767; c=relaxed/simple; bh=VPp2kgu2IZTo1ROx/L0NCpHvqB+X2NUrQ8V97AeUubo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=nv+Hq37+hvs+kWsFBF2VuYHjjzWDfGK4WxJt+KmNuFrdU3m1I+O5QdG7yv1d1KIIBlY+JsqRkNfaNsim4WUSsLvu1WIKBU2I7ZoasmNdxzQ3INr7GMJXHw908MWXP8ZPUdq0KW7n9dPbdItlTHmnjgzQfdLedVQgDz7YKQxMQFo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=xQdeKa5b; 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="xQdeKa5b" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 78CFFC4CEF1; Mon, 27 Oct 2025 19:02:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1761591766; bh=VPp2kgu2IZTo1ROx/L0NCpHvqB+X2NUrQ8V97AeUubo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xQdeKa5bhputUiQnFl9iOCkYmXHsJ9U+XMTSWEldN1DY63r20stg5fyR7HRyo8AGa hOzZw1lOTjmJ1SOf3WPYt0tLft9CJ8/Sx+bIPtPEJzrsr77PE5G3loNBx68sjrfT00 IlJFADK7V+RmfmTVesuxdUMaOwuuHukE74oXFEuY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Brian Norris , Brian Norris , Bjorn Helgaas , Sasha Levin Subject: [PATCH 5.10 322/332] PCI/sysfs: Ensure devices are powered for config reads Date: Mon, 27 Oct 2025 19:36:15 +0100 Message-ID: <20251027183533.371995884@linuxfoundation.org> X-Mailer: git-send-email 2.51.1 In-Reply-To: <20251027183524.611456697@linuxfoundation.org> References: <20251027183524.611456697@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 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ 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 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 @@ -174,8 +174,14 @@ 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); @@ -187,7 +193,10 @@ 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; @@ -204,7 +213,10 @@ 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; @@ -221,7 +233,10 @@ 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; @@ -237,7 +252,10 @@ 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;