[02/12] usb: usbtmc: Support Read Status Byte with SRQ per file handle

[Oliver Neukum <oneukum@suse.com>]

Am Donnerstag, den 24.05.2018, 12:31 +0000 schrieb guido@kiener-
muenchen.de:
> Zitat von Oliver Neukum <oneukum@suse.com>:
> 
> > Am Montag, den 21.05.2018, 21:00 +0000 schrieb guido@kiener-
> > muenchen.de:
> > > 
> > > I looked for a race here, but I do not find a race between open and release,
> > > since a refcount of "file_data->data->kref" is always hold by
> > > usbtmc_probe/disconnect.
> > > 
> > > However I see a race between usbtmc_open and usbtmc_disconnect. Are these
> > > callback functions called mutual exclusive?
> > 
> > No, they are not.
> 
> In the meantime I found these conflictive hints:
> 
> https://github.com/torvalds/linux/commit/52a749992ca6a0fd304609af40ed3bfd6cef4660
> and
> https://elixir.bootlin.com/linux/v4.17-rc6/source/include/linux/usb.h#L1164
> 
> What do you think?
> My current feeling is that open/disconnect is mutual exclusive.
> We also could verify what really happens.

Ok, I remember.

You are safe, if and only if you share the USB minor number space.

	Regards
		Oliver
---
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html