| Message ID | 1240086446.2411.9.camel@poy (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Headers | show |
* Kay Sievers <kay.sievers@vrfy.org> wrote: > On Sat, 2009-04-18 at 22:00 +0200, Kay Sievers wrote: > > On Sat, Apr 18, 2009 at 21:23, Greg KH <gregkh@suse.de> wrote: > > > On Sat, Apr 18, 2009 at 12:19:21PM -0700, Yinghai Lu wrote: > > >> Linus Torvalds wrote: > > > > >> > Can we not make the rule be that the name should just be set before? > > > > I guess, that's what they do already, otherwise they could not use dev_name(). > > > > >> pci_bus_add_device will call device_add. > > >> > > >> actually in device_add > > >> > > >> /* first, register with generic layer. */ > > >> error = kobject_add(&dev->kobj, dev->kobj.parent, "%s", dev_name(dev)); > > >> if (error) > > >> goto Error; > > >> > > >> will get one new name for that kobj, old name is freed. > > >> > > >> Will try to make kobject_add more smart to reuse the old one. > > > > > > I don't understand the problem here, how are you going to change the > > > kobject core? Is this just because you aren't getting a name for the > > > resource? If so, why would the driver core care about this? > > > > Seems a bit odd what we do when registering a device. > > > > Usually one sets the name with dev_set_name() which will name the > > kobject. When one later registers the device, we reallocate the same > > name, so the pointer changes. I guess the problem here is that the pci > > code remembers the name pointer after it was set, but it will not be > > the same after the device is live. > > > > We should probably make device_add() pass a NULL as the name, and > > kobject_add() in that case use the name that is properly set already. > > Only to see if we are on the right track, does that fix the problem? If > yes, we will fix it properly without the NULL hack deep in the kobject > call. > > Thanks, > Kay > > diff --git a/drivers/base/core.c b/drivers/base/core.c > index d230ff4..1969b20 100644 > --- a/drivers/base/core.c > +++ b/drivers/base/core.c > @@ -890,8 +890,8 @@ int device_add(struct device *dev) > if (parent) > set_dev_node(dev, dev_to_node(parent)); > > - /* first, register with generic layer. */ > - error = kobject_add(&dev->kobj, dev->kobj.parent, "%s", dev_name(dev)); > + /* we require the name to be set before, and pass NULL */ > + error = kobject_add(&dev->kobj, dev->kobj.parent, NULL); > if (error) > goto Error; > > diff --git a/lib/kobject.c b/lib/kobject.c > index a6dec32..48565d6 100644 > --- a/lib/kobject.c > +++ b/lib/kobject.c > @@ -218,6 +218,9 @@ int kobject_set_name_vargs(struct kobject *kobj, const char *fmt, > const char *old_name = kobj->name; > char *s; > > + if (kobj->name && !fmt) > + return 0; > + > kobj->name = kvasprintf(GFP_KERNEL, fmt, vargs); > if (!kobj->name) > return -ENOMEM; This looks much cleaner to me - a NULL format string looks like a natural extension. Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Kay Sievers wrote: > On Sat, 2009-04-18 at 22:00 +0200, Kay Sievers wrote: >> On Sat, Apr 18, 2009 at 21:23, Greg KH <gregkh@suse.de> wrote: >>> On Sat, Apr 18, 2009 at 12:19:21PM -0700, Yinghai Lu wrote: >>>> Linus Torvalds wrote: >>>>> Can we not make the rule be that the name should just be set before? >> I guess, that's what they do already, otherwise they could not use dev_name(). >> >>>> pci_bus_add_device will call device_add. >>>> >>>> actually in device_add >>>> >>>> /* first, register with generic layer. */ >>>> error = kobject_add(&dev->kobj, dev->kobj.parent, "%s", dev_name(dev)); >>>> if (error) >>>> goto Error; >>>> >>>> will get one new name for that kobj, old name is freed. >>>> >>>> Will try to make kobject_add more smart to reuse the old one. >>> I don't understand the problem here, how are you going to change the >>> kobject core? Is this just because you aren't getting a name for the >>> resource? If so, why would the driver core care about this? >> Seems a bit odd what we do when registering a device. >> >> Usually one sets the name with dev_set_name() which will name the >> kobject. When one later registers the device, we reallocate the same >> name, so the pointer changes. I guess the problem here is that the pci >> code remembers the name pointer after it was set, but it will not be >> the same after the device is live. >> >> We should probably make device_add() pass a NULL as the name, and >> kobject_add() in that case use the name that is properly set already. > > Only to see if we are on the right track, does that fix the problem? If > yes, we will fix it properly without the NULL hack deep in the kobject > call. > > Thanks, > Kay > > diff --git a/drivers/base/core.c b/drivers/base/core.c > index d230ff4..1969b20 100644 > --- a/drivers/base/core.c > +++ b/drivers/base/core.c > @@ -890,8 +890,8 @@ int device_add(struct device *dev) > if (parent) > set_dev_node(dev, dev_to_node(parent)); > > - /* first, register with generic layer. */ > - error = kobject_add(&dev->kobj, dev->kobj.parent, "%s", dev_name(dev)); > + /* we require the name to be set before, and pass NULL */ > + error = kobject_add(&dev->kobj, dev->kobj.parent, NULL); > if (error) > goto Error; > > diff --git a/lib/kobject.c b/lib/kobject.c > index a6dec32..48565d6 100644 > --- a/lib/kobject.c > +++ b/lib/kobject.c > @@ -218,6 +218,9 @@ int kobject_set_name_vargs(struct kobject *kobj, const char *fmt, > const char *old_name = kobj->name; > char *s; > > + if (kobj->name && !fmt) > + return 0; > + > kobj->name = kvasprintf(GFP_KERNEL, fmt, vargs); > if (!kobj->name) > return -ENOMEM; > it works well. Thanks YH -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sat, 18 Apr 2009, Kay Sievers wrote: > > Only to see if we are on the right track, does that fix the problem? If > yes, we will fix it properly without the NULL hack deep in the kobject > call. ACK, this patch looks much saner, and would seem to address the core issue. Linus -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/base/core.c b/drivers/base/core.c index d230ff4..1969b20 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -890,8 +890,8 @@ int device_add(struct device *dev) if (parent) set_dev_node(dev, dev_to_node(parent)); - /* first, register with generic layer. */ - error = kobject_add(&dev->kobj, dev->kobj.parent, "%s", dev_name(dev)); + /* we require the name to be set before, and pass NULL */ + error = kobject_add(&dev->kobj, dev->kobj.parent, NULL); if (error) goto Error; diff --git a/lib/kobject.c b/lib/kobject.c index a6dec32..48565d6 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -218,6 +218,9 @@ int kobject_set_name_vargs(struct kobject *kobj, const char *fmt, const char *old_name = kobj->name; char *s; + if (kobj->name && !fmt) + return 0; + kobj->name = kvasprintf(GFP_KERNEL, fmt, vargs); if (!kobj->name) return -ENOMEM;