Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [REGRESION] Suspend hangs with 3.6-rc1 on Lenovo T60 notebook | Date | Wed, 15 Aug 2012 21:59:51 +0200 |
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On Wednesday, August 15, 2012, Hans de Goede wrote: > Hi, > > On 08/15/2012 07:13 AM, Miklos Szeredi wrote: > > Suspend oopses in generic_ide_suspend() because dev_get_drvdata() > > returns NULL (dev->p->driver_data == NULL) and this function is not > > prepared for this. > > > > I bisected it to 0998d063 (device-core: Ensure drvdata = NULL when no > > driver is bound). Reverting it fixes suspend. > > > > First of all, thanks for reporting and bisecting this. With that said, > I must say that this is very weird. The patch in question: > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=0998d063 > > Only makes dev-drvdata NULL in 2 cases: > 1) The probe method of the driver fails > 2) The driver has been detached from the device by calling one of: > device_release_driver() or driver_detach() > > Note that in both code paths dev->driver also gets set to NULL, and > other generic ide driver callbacks very much depend on that not being > NULL, ie: > > static int generic_ide_remove(struct device *dev) > { > ide_drive_t *drive = to_ide_device(dev); > struct ide_driver *drv = to_ide_driver(dev->driver); > > if (drv->remove) > drv->remove(drive); > > return 0; > } > > Also how can a drivers suspend callback get called if dev->driver is NULL, > since that callback would normally be "reached" through dev->driver, so > something weird is going on here ...
No, it wouldn't, because it is a bus type callback and it is invoked for all devices whose bus type is ide_bus_type, regardless of whether or not their driver field is NULL.
It clearly should check if drive is not NULL before using that pointer.
Thanks, Rafael
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