linux-kernel - [BUGFIX -v3 1/4] PCI/PM: enable D3/D3cold by default for most devices

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:	Wed,  8 Aug 2012 09:07:38 +0800
From:	Huang Ying <ying.huang@...el.com>
To:	Bjorn Helgaas <bhelgaas@...gle.com>
Cc:	linux-kernel@...r.kernel.org, linux-pci@...r.kernel.org,
	linux-pm@...r.kernel.org, "Rafael J. Wysocki" <rjw@...k.pl>,
	Huang Ying <ying.huang@...el.com>,
	Alan Stern <stern@...land.harvard.edu>
Subject: [BUGFIX -v3 1/4] PCI/PM: enable D3/D3cold by default for most devices

This patch fixes the following bug:

http://marc.info/?l=linux-usb&m=134318961120825&w=2

Originally, device lower power states include D1, D2, D3.  After that,
D3 is further divided into D3hot and D3cold.  To support both scenario
safely, original D3 is mapped to D3cold.

When adding D3cold support, because worry about some device may have
broken D3cold support, D3cold is disabled by default.  This disable D3
on original platform too.  But some original platform may only have
working D3, but no working D1, D2.  The root cause of the above bug is
it too.

To deal with this, this patch enables D3/D3cold by default for most
devices.  This restores the original behavior.  For some devices that
suspected to have broken D3cold support, such as PCIe port, D3cold is
disabled by default.

Reported-by: Bjorn Mork <bjorn@...k.no>
Signed-off-by: Huang Ying <ying.huang@...el.com>
Reviewed-by: Rafael J. Wysocki <rjw@...k.pl>
---
 drivers/pci/pci.c              |    1 +
 drivers/pci/pcie/portdrv_pci.c |    5 +++++
 2 files changed, 6 insertions(+)

--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1941,6 +1941,7 @@ void pci_pm_init(struct pci_dev *dev)
 	dev->pm_cap = pm;
 	dev->d3_delay = PCI_PM_D3_WAIT;
 	dev->d3cold_delay = PCI_PM_D3COLD_WAIT;
+	dev->d3cold_allowed = true;

 	dev->d1_support = false;
 	dev->d2_support = false;
--- a/drivers/pci/pcie/portdrv_pci.c
+++ b/drivers/pci/pcie/portdrv_pci.c
@@ -200,6 +200,11 @@ static int __devinit pcie_portdrv_probe(
 		return status;

 	pci_save_state(dev);
+	/*
+	 * D3cold may not work properly on some PCIe port, so disable
+	 * it by default.
+	 */
+	dev->d3cold_allowed = false;
 	if (!pci_match_id(port_runtime_pm_black_list, dev))
 		pm_runtime_put_noidle(&dev->dev);

--
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/