Re: [PATCH 1/2]drivers/usb/core/sysfs.c Fix variable 'retval' setbut not used

From: Alan Stern
Date: Tue Aug 03 2010 - 10:30:04 EST


On Tue, 3 Aug 2010 Valdis.Kletnieks@xxxxxx wrote:

> On Mon, 02 Aug 2010 21:26:28 PDT, "Justin P. Mattock" said:
> > diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c
>
> > if (alt->string)
> > - retval = device_create_file(&intf->dev, &dev_attr_interface);
> > + device_create_file(&intf->dev, &dev_attr_interface);
> > intf->sysfs_files_created = 1;
> > return 0;

Justin, did you try compiling your new code? Those unused values are
there because device_create_file is declared as __must_check.

> What should the code do if device_create_file() manages to fail? Yes, ignoring
> the return value is one option, but is it the best one? 'return ret;' might be
> another one. Somebody who understands this code and has more caffeine than me
> should look this over.

Failure to create a file in sysfs is almost never fatal and usually not
even dangerous. Ignoring the error is generally better than failing
the entire operation.

Alan Stern

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/