linux-kernel - [RFC PATCH v2 04/12] PCI: properly clean up ASPM link state on device remove

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 13 Feb 2009 13:19:13 -0700
From:	Alex Chiang <achiang@...com>
To:	jbarnes@...tuousgeek.org
Cc:	linux-pci@...r.kernel.org, linux-kernel@...r.kernel.org,
	Shaohua Li <shaohua.li@...el.com>, Alex Chiang <achiang@...com>
Subject: [RFC PATCH v2 04/12] PCI: properly clean up ASPM link state on device
	remove

We only want to disable ASPM when the last function is removed from
the parent's device list. We determine this by checking to see if
the parent's device list is completely empty.

Unfortunately, we never hit that code because the parent is considered
an upstream port, and never had an ASPM link_state associated with it.

The early check for !link_state causes us to return early, we never
discover that our device list is empty, and thus we never remove the
downstream ports' link_state nodes.

Instead of checking to see if the parent's device list is empty, we can
check to see if we are the last device on the list, and if so, then we
know that we can clean up properly.

Cc: Shaohua Li <shaohua.li@...el.com>
Signed-off-by: Alex Chiang <achiang@...com>
---

 drivers/pci/pcie/aspm.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
index 586b6f7..b0367f1 100644
--- a/drivers/pci/pcie/aspm.c
+++ b/drivers/pci/pcie/aspm.c
@@ -718,9 +718,9 @@ void pcie_aspm_exit_link_state(struct pci_dev *pdev)

 	/*
 	 * All PCIe functions are in one slot, remove one function will remove
-	 * the the whole slot, so just wait
+	 * the whole slot, so just wait until we are the last function left.
 	 */
-	if (!list_empty(&parent->subordinate->devices))
+	if (!list_is_last(&pdev->bus_list, &parent->subordinate->devices))
 		goto out;

 	/* All functions are removed, so just disable ASPM for the link */

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/