From 2449e06a5696b7af1c8a369b04c97f3b139cf3bb Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Fri, 20 Oct 2006 14:45:32 -0700 Subject: [PATCH] PCI: reset pci device state to unknown state for resume Considering below scenario: 1.Unload a PCI device's driver, the device ->current remains in PCI_D0. 2.Do suspend/resume circle. After that, BIOS puts the device to D3. 3.Reload the device driver. The calling pci_set_power_state in the driver can't change the state to D0, as set_power_state thinks the device is already in D0. A bug is reported at http://bugzilla.kernel.org/show_bug.cgi?id=6024 Pat attached a patch at http://marc.theaimsgroup.com/?l=linux-pci&m=114049761428561&w=2 for this issue, but it's lost. As pci_set_power_state can handle D3 -> D0 correctly (restore config space), I simplified Patrick's patch. Signed-off-by: Shaohua Li Cc: Patrick Mochel Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- drivers/pci/pci-driver.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index b1c0c707d96c..194f1d21d3d7 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -264,6 +264,13 @@ static int pci_device_remove(struct device * dev) pci_dev->driver = NULL; } + /* + * If the device is still on, set the power state as "unknown", + * since it might change by the next time we load the driver. + */ + if (pci_dev->current_state == PCI_D0) + pci_dev->current_state = PCI_UNKNOWN; + /* * We would love to complain here if pci_dev->is_enabled is set, that * the driver should have called pci_disable_device(), but the @@ -288,6 +295,12 @@ static int pci_device_suspend(struct device * dev, pm_message_t state) suspend_report_result(drv->suspend, i); } else { pci_save_state(pci_dev); + /* + * mark its power state as "unknown", since we don't know if + * e.g. the BIOS will change its device state when we suspend. + */ + if (pci_dev->current_state == PCI_D0) + pci_dev->current_state = PCI_UNKNOWN; } return i; } -- 2.20.1