From: "Rafael J. Wysocki" <rjw@sisk.pl>
To: andi@lisas.de
Cc: akpm@linux-foundation.org, e1000-devel@lists.sourceforge.net,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Make e100 suspend handler support PCI cards lacking PM capability
Date: Sun, 14 Jun 2009 00:28:15 +0200 [thread overview]
Message-ID: <200906140028.16025.rjw@sisk.pl> (raw)
In-Reply-To: <20090613191931.GA31019@rhlx01.hs-esslingen.de>
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 <andi@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.
Best,
Rafael
next prev parent reply other threads:[~2009-06-13 22:27 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-12-28 8:01 [GIT]: Networking David Miller
2008-12-29 10:25 ` Andreas Mohr
2008-12-29 17:17 ` Andrew Morton
2008-12-29 21:09 ` Johannes Berg
2008-12-30 11:05 ` Andreas Mohr
2008-12-29 23:15 ` Jeff Kirsher
2008-12-30 12:07 ` Andreas Mohr
2009-02-28 20:37 ` 2.6.29 e100.c non-MII support status? (Re: [GIT]: Networking) Andreas Mohr
2009-03-01 10:57 ` Jeff Kirsher
2009-03-01 21:24 ` Andreas Mohr
2009-06-02 21:48 ` [PATCH] Add non-MII PHY support to e100 (Re: 2.6.29 e100.c non-MII support status? (Re: [GIT]: Networking)) Andreas Mohr
2009-06-03 6:01 ` e100 kills S2R on my box, plus network drops dead Andreas Mohr
2009-06-03 6:30 ` Andreas Mohr
2009-06-13 19:19 ` [PATCH] Make e100 suspend handler support PCI cards lacking PM capability Andreas Mohr
2009-06-13 22:28 ` Rafael J. Wysocki [this message]
2009-06-13 22:45 ` Rafael J. Wysocki
2009-06-14 12:51 ` Andreas Mohr
2009-06-14 14:06 ` Rafael J. Wysocki
2009-06-14 16:31 ` Rafael J. Wysocki
2009-06-14 16:46 ` Andreas Mohr
2009-06-14 17:09 ` Rafael J. Wysocki
2009-06-14 17:20 ` Andreas Mohr
2009-06-19 8:00 ` Andreas Mohr
2009-06-14 19:46 ` [PATCH] Net / e100: Fix suspend of devices that cannot be power managed Rafael J. Wysocki
2009-06-18 2:03 ` David Miller
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