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 B164A330D4D for ; Thu, 16 Oct 2025 12:57:52 +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=1760619472; cv=none; b=gqw7y8oCjdxNVKsf4DVzAsnccjHJEG4C7FKsaNECStffS8IBtkueQz9vXG81Z7hVTv3flahFSfnbyjNN9W+idbmdRxK2ZU7u8IW96iawb/9+iqe5QTMsUgafzrhfK+497jGh3XsG/0gUyI2t7235rU7chpMslx/7uF57JviqDXE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760619472; c=relaxed/simple; bh=rgL7UDS/F+DVekJ6m0URpHODFVWUDB4FEhG/puzfYug=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=Kg1D/3SnQWWHYiqai3943xu1F1vuX4RZYFhf5rzqzmfOHS4H0dS6oL0vJTxWsbl+ZI1n0qZ6qv2uvRcwZE3u9olhu6RhzljkIs31XLTVwfDmjTE8gz3jVmgL2KfKls1aB3O5taPELfc61WuUfUT+DHPodbHMUWA9plfXdrPYB8o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Xzy20Fyq; 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="Xzy20Fyq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 27126C4CEF1; Thu, 16 Oct 2025 12:57:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760619472; bh=rgL7UDS/F+DVekJ6m0URpHODFVWUDB4FEhG/puzfYug=; h=Subject:To:Cc:From:Date:From; b=Xzy20FyqxYPwWl8ifHX1hsEcBT3dYh7hPoxYE5QuI4TV/fLtRq+ZJeI/u2EtAdD7z 1re2Lnjogv8S81X07+fMTWm3HmU+gQriP5gRCPbYZrobVBeNuzG1r5YYR4NyXGjbT8 S7StFQCkuhEuPcuCaN/Qu04OLqmGxApQ6ihQEElU= Subject: FAILED: patch "[PATCH] PCI/sysfs: Ensure devices are powered for config reads" failed to apply to 5.4-stable tree To: briannorris@google.com,bhelgaas@google.com,briannorris@chromium.org Cc: From: Date: Thu, 16 Oct 2025 14:57:41 +0200 Message-ID: <2025101641-squire-emboss-834e@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 48991e4935078b05f80616c75d1ee2ea3ae18e58 # git commit -s git send-email --to '' --in-reply-to '2025101641-squire-emboss-834e@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 48991e4935078b05f80616c75d1ee2ea3ae18e58 Mon Sep 17 00:00:00 2001 From: Brian Norris Date: Wed, 24 Sep 2025 09:57:11 -0700 Subject: [PATCH] PCI/sysfs: Ensure devices are powered for config reads 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 diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 5eea14c1f7f5..2b231ef1dac9 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -201,8 +201,14 @@ 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); @@ -214,7 +220,10 @@ 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; @@ -231,7 +240,10 @@ 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; @@ -247,7 +259,10 @@ 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; @@ -263,7 +278,10 @@ 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;