[PATCH update] Re: Sleep problems with kernels >= 2.6.21 on powerpc
From: Stefan Richter
Date: Thu Sep 06 2007 - 03:51:23 EST
On 5 Sep, Stefan Richter wrote:
> On 5 Sep, Andrew Morton wrote:
>>> >>> Trying to free already-free IRQ 40
>>> >>> pci_set_power_state(): 0002:20:0e.0: state=3, current state=5
>>> >>> firewire_ohci: pci_set_power_state failed with -22<3>pci_device_suspend(): pci_suspend+0x0/0x9c [firewire_ohci]() returns -22
...
>> It's not clear _why_ pci_set_power_state() is failing.
>
> The only -22 error path in pci_set_power_state is this:
>
> /* Validate current state:
> * Can enter D0 from any state, but if we can only go deeper
> * to sleep if we're already in a low power state
> */
> if (state != PCI_D0 && dev->current_state > state) {
> printk(KERN_ERR "%s(): %s: state=%d, current state=%d\n",
> __FUNCTION__, pci_name(dev), state, dev->current_state);
> return -EINVAL;
> } [...else...]
From: Stefan Richter <stefanr@xxxxxxxxxxxxxxxxx>
Subject: firewire: fw-ohci: ignore failure of pci_set_power_state (fix suspend regression)
Fixes (papers over) "Sleep problems with kernels >= 2.6.21 on powerpc",
http://lkml.org/lkml/2007/8/25/155. The issue is that the FireWire
controller's pci_dev.current_state of iBook G3 and presumably older
PowerBooks is still in PCI_UNKNOWN instead of PCI_D0 when the firewire
driver's .suspend method is called.
Like it was suggested earlier in http://lkml.org/lkml/2006/10/24/13, we
do not fail .suspend anymore if pci_set_power_state failed.
Signed-off-by: Stefan Richter <stefanr@xxxxxxxxxxxxxxxxx>
---
Update:
- omit comment which will become outdated if the underlying problem is fixed
- log the error return value
- document the actual bug in the patch description
IMO the actual bug here (operating the controller while it is in
PCI_UNKNOWN state, which is surely a fault in the PPC platform code) is
something to be fixed post 2.6.23 release.
drivers/firewire/fw-ohci.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
Index: linux/drivers/firewire/fw-ohci.c
===================================================================
--- linux.orig/drivers/firewire/fw-ohci.c
+++ linux/drivers/firewire/fw-ohci.c
@@ -1973,10 +1973,8 @@ static int pci_suspend(struct pci_dev *p
return err;
}
err = pci_set_power_state(pdev, pci_choose_state(pdev, state));
- if (err) {
- fw_error("pci_set_power_state failed\n");
- return err;
- }
+ if (err)
+ fw_error("pci_set_power_state failed with %d\n", err);
return 0;
}
--
Stefan Richter
-=====-=-=== =--= --==-
http://arcgraph.de/sr/
-
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