On Wed, Jul 22, 2015 at 02:39:34PM -0700, Greg Kroah-Hartman wrote:
> On Tue, Jun 23, 2015 at 01:57:38PM +0300, Heikki Krogerus wrote:
> > On Fri, Jun 19, 2015 at 01:12:36AM +0800, ChengYi He wrote:
> > > put_device is required to release the last reference to the device.
> > >
> > > Signed-off-by: ChengYi He <chengyihetaipei@xxxxxxxxx>
> > > ---
> > > drivers/usb/common/ulpi.c | 4 +++-
> > > 1 file changed, 3 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/usb/common/ulpi.c b/drivers/usb/common/ulpi.c
> > > index 0e6f968..bd25bdb 100644
> > > --- a/drivers/usb/common/ulpi.c
> > > +++ b/drivers/usb/common/ulpi.c
> > > @@ -184,8 +184,10 @@ static int ulpi_register(struct device *dev, struct ulpi *ulpi)
> > > request_module("ulpi:v%04xp%04x", ulpi->id.vendor, ulpi->id.product);
> > >
> > > ret = device_register(&ulpi->dev);
> > > - if (ret)
> > > + if (ret) {
> > > + put_device(&ulpi->dev);
> >
> > If device_register returns failure, put_device has already been
> > called. Check device_add in drivers/base/core.c.
>
> Yes, please read the function, which says:
> * NOTE: _Never_ directly free @dev after calling this function, even
> * if it returned an error! Always use put_device() to give up your
> * reference instead.
>
> But, the problem is that the ulpi core doesn't "own" that struct device.
> It comes from elsewhere. It comes from somewhere deep down in the dw3
> core, which is where I lost the path. Something needs to be fixed in
> dwc3_probe() to properly clean up the device if it fails, which is not
> happening right now.
>
> So this patch would actually cause much bigger problems than fixing
> anything, so it's wrong, but for a different reason than you are talking
> about here.
>
> And ugh, the ulpi and dwc code binding together, what a mess, horrid...
any suggestions ? DWC *is* the one implementing the bus. If there's a
better way, we can certainly shuffle code around.
--
balbi
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