On Sunday 14 June 2009, Rafael J. Wysocki wrote:
> On Saturday 13 June 2009, Andreas Mohr wrote:
> > Hi all,
> >
> > after having added non-MII PHY card support to e100, I noticed that
> > the suspend handler rejects power-management non-capable PCI cards,
>
> Well, that means we have a bug somewhere in the PCI PM core.
>
> > causing a S2R request to immediately get back up to the desktop,
> > losing network access in the process (rtnl mutex deadlock).
>
> That's bad.
>
> >
> > ChangeLog:
> > Support PCI cards which are lacking power management capability
> > in the e100 suspend handler.
> >
> >
> > Frankly I was unsure how to best add this to the driver in a clean way.
> > Usually drivers use pci_set_power_state(..., pci_choose_state(...))
> > in order to avoid the rejection of an open-coded
> > pci_set_power_state(..., PCI_D3hot) in case of a non-PM card,
> > however pci_choose_state() depends on the _pm-internal_ pm_message_t type,
> > which was doable in .suspend directly but not at the other e100
> > driver locations where it was used.
> >
> > Next attempt was to extend __e100_power_off() with a pci_power_t parameter,
> > however since __e100_power_off() is called by two locations,
> > that meant that I'd have to use pci_choose_state() at _both_ call sites.
> >
> > Thus I simply resorted to do a brute-force yet most simple
> > pci_find_capability() check in the __e100_power_off() function.
> >
> >
> > Tested on 2.6.30-rc8 and suspending/resuming fine, checkpatch.pl:ed.
> > Patch against 2.6.30-rc8 with my original non-MII support patch applied.
> > (should apply fine in any case, I'd think).
> > Intended for testing in -mmotm or so.
> >
> > Thanks!
> >
> > Signed-off-by: Andreas Mohr <a...@lisas.de>
> >
> >
> > --- linux-2.6.30-rc8.e100/drivers/net/e100.c.my_patch_orig 2009-06-13
> > 18:47:53.000000000 +0200
> > +++ linux-2.6.30-rc8.e100/drivers/net/e100.c 2009-06-13
> > 20:27:46.000000000 +0200
> > @@ -2897,6 +2897,13 @@ static void __e100_shutdown(struct pci_d
> >
> > static int __e100_power_off(struct pci_dev *pdev, bool wake)
> > {
> > + /* some older devices don't support PCI PM
> > + * (e.g. mac_82557_D100_B combo card with 80c24 PHY)
> > + * - skip those! (they most likely won't support WoL either)
> > + */
> > + if (!pci_find_capability(pdev, PCI_CAP_ID_PM))
> > + return 0;
>
> Devices without PCI_CAP_ID_PM may still be power-manageable by ACPI, so
> returning 0 at this point is not a general solution.
>
> > +
> > if (wake) {
> > return pci_prepare_to_sleep(pdev);
>
> pci_prepare_to_sleep() is supposed to return 0 for your device. I'll have a
> look at it.
Please check if the appended patch helps.
Best,
Rafael
---
drivers/pci/pci.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
Index: linux-2.6/drivers/pci/pci.c
===================================================================
--- linux-2.6.orig/drivers/pci/pci.c
+++ linux-2.6/drivers/pci/pci.c
@@ -1284,15 +1284,14 @@ pci_power_t pci_target_state(struct pci_
default:
target_state = state;
}
+ } else if (!dev->pm_cap) {
+ target_state = PCI_D0;
} else if (device_may_wakeup(&dev->dev)) {
/*
* Find the deepest state from which the device can generate
* wake-up events, make it the target state and enable device
* to generate PME#.
*/
- if (!dev->pm_cap)
- return PCI_POWER_ERROR;
-
if (dev->pme_support) {
while (target_state
&& !(dev->pme_support & (1 << target_state)))
------------------------------------------------------------------------------
Crystal Reports - New Free Runtime and 30 Day Trial
Check out the new simplified licensing option that enables unlimited
royalty-free distribution of the report engine for externally facing
server and web deployment.
http://p.sf.net/sfu/businessobjects
_______________________________________________
E1000-devel mailing list
E1000-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/e1000-devel
