The patch titled
reset pci device state to unknown state for resume
has been added to the -mm tree. Its filename is
reset-pci-device-state-to-unknown-state-for-resume.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: reset pci device state to unknown state for resume
From: Shaohua Li <shaohua.li@xxxxxxxxx>
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 <shaohua.li@xxxxxxxxx>
Cc: Greg KH <greg@xxxxxxxxx>
Cc: Patrick Mochel <mochel@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
drivers/pci/pci-driver.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff -puN drivers/pci/pci-driver.c~reset-pci-device-state-to-unknown-state-for-resume drivers/pci/pci-driver.c
--- a/drivers/pci/pci-driver.c~reset-pci-device-state-to-unknown-state-for-resume
+++ a/drivers/pci/pci-driver.c
@@ -265,6 +265,13 @@ static int pci_device_remove(struct devi
}
/*
+ * 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
* unfortunate fact is there are too many odd BIOS and bridge setups
@@ -288,6 +295,12 @@ static int pci_device_suspend(struct dev
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;
}
_
Patches currently in -mm which might be from shaohua.li@xxxxxxxxx are
reset-pci-device-state-to-unknown-state-for-resume.patch
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