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 894A132C931; Fri, 17 Oct 2025 15:10:03 +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=1760713803; cv=none; b=Vednt3o6tAkbhYJaclFLpj3EkG4QWlvwMRMq0L0313to8n231R5tjkjXi9XRGllUhGohHce2du3dOiXzdlfkabFtrTX8NuSEFrA4wn+1txkMd3DjX1I8M0Mz7DzwaTquuS1rzKlbOFfN3g9iWQg6weNoJ26RQrl7aldJYtoLAhY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760713803; c=relaxed/simple; bh=l4Tc/PGWzCPWXxNe30/bS/lIr4a5gMpPLd6GQE32WvM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bpGLYWGhMtHggxzb8ze52KgLVzu55hBKQ2W5gRWj7NpTY4YsVohOhAvoVOe3k3/OMyzfaXbIZ82+jrttgdJa2YPqOBHgR2zQXud62AtZKaa9KfJs/r0q9TDDEfPBod3a1D+R43vwQnxoVB/gJ6zMjGIbHnd32+zMuAQrijmYtCw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Tn3esRtW; 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="Tn3esRtW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1236DC4CEE7; Fri, 17 Oct 2025 15:10:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760713803; bh=l4Tc/PGWzCPWXxNe30/bS/lIr4a5gMpPLd6GQE32WvM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Tn3esRtWKgWlQ/OlGnTdx0OOzzXbamgZHXbpUBJ2jFYuaUcQDukHvMZCr8Htm7vSr lz3NMotTI6Q5zFk/WZsOJupuEn2dONHlfZ7ysKuoG0RDcZd/6hFiXSX+JSd9IpmsBr 9bd3bTU3gggBSCF8+jHJGXQMYlh/BWRdM+7+dZrc= 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 6.6 126/201] PCI/sysfs: Ensure devices are powered for config reads Date: Fri, 17 Oct 2025 16:53:07 +0200 Message-ID: <20251017145139.369369987@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251017145134.710337454@linuxfoundation.org> References: <20251017145134.710337454@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 6.6-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 @@ -196,8 +196,14 @@ 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); @@ -209,7 +215,10 @@ 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; @@ -226,7 +235,10 @@ 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; @@ -242,7 +254,10 @@ 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; @@ -258,7 +273,10 @@ 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;