From: Miklos Szeredi <miklos@szeredi.hu>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: Hans de Goede <hdegoede@redhat.com>,
"Rafael J. Wysocki" <rjw@sisk.pl>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Tejun Heo <tj@kernel.org>, <linux-kernel@vger.kernel.org>,
<linux-pm@vger.kernel.org>
Subject: Re: [REGRESION] Suspend hangs with 3.6-rc1 on Lenovo T60 notebook
Date: Thu, 16 Aug 2012 18:29:45 +0200 [thread overview]
Message-ID: <87obmals06.fsf@tucsk.pomaz.szeredi.hu> (raw)
In-Reply-To: <Pine.LNX.4.44L0.1208161106350.24305-100000@netrider.rowland.org> (Alan Stern's message of "Thu, 16 Aug 2012 11:13:33 -0400 (EDT)")
Alan Stern <stern@rowland.harvard.edu> writes:
> On Thu, 16 Aug 2012, Hans de Goede wrote:
>
>> Ah right, these are bus_driver operations. That explains some things, so I've
>> done some more research asking myself: "Why does generic_ide_suspend(), which
>> is a *bus* op, call dev_get_drvdata?", the answer to that seems to be that
>> the ide subsystem is abusing (IMHO) drvdata to store per device bus_driver
>> data. Which I believe is not how drvdata is intended to be used.
>>
>> With that said, the above knowledge has allowed me to write an (ugly) fix for
>> the regression Miklos is seeing. Miklos can you give the attached patch a
>> try please?
>>
>> > It clearly should check if drive is not NULL before using that pointer.
>>
>> I assume you mean drive*r*, yes I agree that generic_ide_remove should
>> check for that. So who is going to write a patch for that?
>
> The existing code could certainly be improved. Your patch does:
>
>> + /*
>> + * device_register() will have cleared drvdata on
>> + * device_attach failure, but we use drvdata to store per
>> + * device bus info, rather then for driver info, so restore it.
>> + */
>> + dev_set_drvdata(dev, drive);
>
> But at this point, dev is defined by:
>
> struct device *dev = &drive->gendev;
>
> So why bother setting anything? It seems to me that
> generic_ide_suspend() and generic_ide_resume() could easily replace
>
> ide_drive_t *drive = dev_get_drvdata(dev);
>
> with
>
> ide_drive_t *drive = dev_to_ide_drive(dev);
>
> where dev_to_ide_drive is defined as "container_of(dev, ide_drive_t,
> gendev)" (if this isn't defined already).
Yes, this appears to work. Following patch fixes the suspend oops.
Thanks,
Miklos
---
drivers/ide/ide-pm.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/ide/ide-pm.c b/drivers/ide/ide-pm.c
index 9240609..8d1e32d 100644
--- a/drivers/ide/ide-pm.c
+++ b/drivers/ide/ide-pm.c
@@ -4,7 +4,7 @@
int generic_ide_suspend(struct device *dev, pm_message_t mesg)
{
- ide_drive_t *drive = dev_get_drvdata(dev);
+ ide_drive_t *drive = to_ide_device(dev);
ide_drive_t *pair = ide_get_pair_dev(drive);
ide_hwif_t *hwif = drive->hwif;
struct request *rq;
@@ -40,7 +40,7 @@ int generic_ide_suspend(struct device *dev, pm_message_t mesg)
int generic_ide_resume(struct device *dev)
{
- ide_drive_t *drive = dev_get_drvdata(dev);
+ ide_drive_t *drive = to_ide_device(dev);
ide_drive_t *pair = ide_get_pair_dev(drive);
ide_hwif_t *hwif = drive->hwif;
struct request *rq;
--
1.7.7
next prev parent reply other threads:[~2012-08-16 16:28 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <87a9xwivqb.fsf@tucsk.pomaz.szeredi.hu>
2012-08-15 6:41 ` [REGRESION] Suspend hangs with 3.6-rc1 on Lenovo T60 notebook Hans de Goede
2012-08-15 19:59 ` Rafael J. Wysocki
2012-08-16 11:34 ` Hans de Goede
2012-08-16 15:13 ` Alan Stern
2012-08-16 16:29 ` Miklos Szeredi [this message]
2012-08-16 16:32 ` Alan Stern
2012-08-16 20:02 ` Rafael J. Wysocki
2012-08-17 9:23 ` Hans de Goede
2012-08-17 14:22 ` Alan Stern
2012-08-17 14:27 ` Alan Stern
2012-08-17 15:32 ` Hans de Goede
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