On Mon, Jan 21, 2019 at 03:35:34PM +0100, Greg KH wrote:
> On Mon, Jan 21, 2019 at 11:30:55PM +0900, Suwan Kim wrote:
> > usb_create_ep_devs() returns error code if an error occurs. But
> > usb_new_device() and create_intf_ep_devs() which use usb_create_ep_devs()
> > to create endpoint devices ignore the error and cut the propagation
> > of the error when usb_create_ep_devs() fails. So, usb_create_ep_devs()
> > prints an error message for debugging or notification purposes if an
> > error occurs.
> >
> > Signed-off-by: Suwan Kim <suwan.kim027@xxxxxxxxx>
> > ---
> > drivers/usb/core/endpoint.c | 5 ++++-
> > 1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/usb/core/endpoint.c b/drivers/usb/core/endpoint.c
> > index 1c2c04079676..ad3902c023d9 100644
> > --- a/drivers/usb/core/endpoint.c
> > +++ b/drivers/usb/core/endpoint.c
> > @@ -182,6 +182,7 @@ int usb_create_ep_devs(struct device *parent,
> >
> > ep_dev = kzalloc(sizeof(*ep_dev), GFP_KERNEL);
> > if (!ep_dev) {
> > + dev_err(parent, "endpoint device alloc failed\n");
>
> kzalloc() prints out an error if it fails, why print out it again here?
>
> > retval = -ENOMEM;
> > goto exit;
> > }
> > @@ -194,8 +195,10 @@ int usb_create_ep_devs(struct device *parent,
> > dev_set_name(&ep_dev->dev, "ep_%02x", endpoint->desc.bEndpointAddress);
> >
> > retval = device_register(&ep_dev->dev);
> > - if (retval)
> > + if (retval) {
> > + dev_err(parent, "endpoint device register failed\n");
>
> Doesn't device_add() provide an error if this fails? If not, what can
> we do about it here?
>
> And even if you do want this message, it's not the parent that failed to
> register, so this might be a bit misleading of a message.
Oh... I was misunderstading. Thank you for pointing out.
> What problem are you having that you are trying to fix here? Have you
> seen the call to device_register() fail for an endpoint?
>
> thanks,
>
> greg k-h
Thank you very much for reviewing my code. I did not see the error
actually happening. I just wanted to fix things about ignoring errors.
I will discard this patch if there are really few errors.
Regards
Suwan Kim
