From: Alex Williamson <alex.williamson@redhat.com>
To: linux-pci@vger.kernel.org
Cc: bhelgaas@google.com, indou.takao@jp.fujitsu.com
Subject: [RFC PATCH 7/7] pci: Wake-up devices before save for reset
Date: Tue, 30 Jul 2013 21:32:12 -0600 [thread overview]
Message-ID: <20130731033212.31931.94340.stgit@bling.home> (raw)
In-Reply-To: <20130731031316.31931.56751.stgit@bling.home>
Devices come out of reset in D0. Restoring a device to a different
post-reset state takes more smarts than our simple config space
restore, which can leave devices in an inconsistent state. For
example, if a device is reset in D3, but the restore doesn't
successfully return the device to D3, then the actual state of the
device and dev->current_state are contradictory. Put everything
in D0 going into the reset, then we don't need to do anything
special on the way out.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
---
drivers/pci/pci.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 91f7bc4..3e71887 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -3393,6 +3393,13 @@ static void pci_dev_unlock(struct pci_dev *dev)
static void pci_dev_save_and_disable(struct pci_dev *dev)
{
+ /*
+ * Wake-up device prior to save. PM registers default to D0 after
+ * reset and a simple register restore doesn't reliably return
+ * to a non-D0 state anyway.
+ */
+ pci_set_power_state(dev, PCI_D0);
+
pci_save_state(dev);
/*
* both INTx and MSI are disabled after the Interrupt Disable bit
prev parent reply other threads:[~2013-07-31 3:32 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-31 3:31 [RFC PATCH 0/7] pci: bus and slot reset interfaces Alex Williamson
2013-07-31 3:31 ` [RFC PATCH 1/7] pci: Create pci_reset_bridge_secondary_bus() Alex Williamson
2013-07-31 3:31 ` [RFC PATCH 2/7] pci: Add hotplug_slot_ops.reset_slot() Alex Williamson
2013-07-31 3:31 ` [RFC PATCH 3/7] pci: Implement reset_slot for pciehp Alex Williamson
2013-07-31 3:31 ` [RFC PATCH 4/7] pci: Add slot reset option to pci_dev_reset Alex Williamson
2013-07-31 3:32 ` [RFC PATCH 5/7] pci: Split out pci_dev lock/unlock and save/restore Alex Williamson
2013-07-31 3:32 ` [RFC PATCH 6/7] pci: Add slot and bus reset interfaces Alex Williamson
2013-07-31 3:32 ` Alex Williamson [this message]
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