Messages in this thread | | | Date | Sat, 28 Sep 2019 09:41:24 +0200 | From | Greg Kroah-Hartman <> | Subject | Re: [PATCH] powerpc/vio: use simple dummy struct device as bus parent |
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On Fri, Sep 27, 2019 at 03:48:49PM -0400, Dan Streetman wrote: > On Fri, Sep 27, 2019 at 2:19 PM Greg Kroah-Hartman > <gregkh@linuxfoundation.org> wrote: > > > > On Fri, Sep 27, 2019 at 09:04:02AM -0400, Dan Streetman wrote: > > > The dummy vio_bus_device creates the /sys/devices/vio directory, which > > > contains real vio devices under it; since it represents itself as having > > > a bus = &vio_bus_type, its /sys/devices/vio/uevent does call the bus's > > > .uevent function, vio_hotplug(), and as that function won't find a real > > > device for the dummy vio_dev, it will return -ENODEV. > > > > > > One of the main users of the uevent node is udevadm, e.g. when it is called > > > with 'udevadm trigger --devices'. Up until recently, it would ignore any > > > errors returned when writing to devices' uevent file, but it was recently > > > changed to start returning error if it gets an error writing to any uevent > > > file: > > > https://github.com/systemd/systemd/commit/97afc0351a96e0daa83964df33937967c75c644f > > > > > > since the /sys/devices/vio/uevent file has always returned ENODEV from > > > any write to it, this now causes the udevadm trigger command to return > > > an error. This may be fixed in udevadm to ignore ENODEV errors, but the > > > vio driver should still be fixed. > > > > > > This patch changes the arch/powerpc/platform/pseries/vio.c 'dummy' > > > parent device into a real dummy device with no .bus, so its uevent > > > file will stop returning ENODEV and simply do nothing and return 0. > > > > > > Signed-off-by: Dan Streetman <ddstreet@canonical.com> > > > --- > > > arch/powerpc/platforms/pseries/vio.c | 11 ++++------- > > > 1 file changed, 4 insertions(+), 7 deletions(-) > > > > > > diff --git a/arch/powerpc/platforms/pseries/vio.c b/arch/powerpc/platforms/pseries/vio.c > > > index 79e2287991db..63bc16631680 100644 > > > --- a/arch/powerpc/platforms/pseries/vio.c > > > +++ b/arch/powerpc/platforms/pseries/vio.c > > > @@ -32,11 +32,8 @@ > > > #include <asm/page.h> > > > #include <asm/hvcall.h> > > > > > > -static struct vio_dev vio_bus_device = { /* fake "parent" device */ > > > - .name = "vio", > > > - .type = "", > > > - .dev.init_name = "vio", > > > - .dev.bus = &vio_bus_type, > > > +static struct device vio_bus = { > > > + .init_name = "vio", > > > > Eeek, no! Why are you creating a static device that will then be > > reference counted? Not nice :( > > sorry! I'll admit that I simply copied what drivers/base/platform.c > seemed to be doing.
I don't see platform.c having a 'static struct device' anywhere in it, am I missing it in my searching?
thanks,
greg k-h
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