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From: Arnd Bergmann <arnd@arndb.de>
To: outreachy-kernel@googlegroups.com
Cc: y2038@lists.linaro.org, Deepa Dinamani <deepa.kernel@gmail.com>
Subject: Re: [Outreachy kernel] Re: [Y2038] [PATCH] usb: usbtest: Add new ioctl interface
Date: Sat, 24 Oct 2015 10:38:59 +0200
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On Saturday 24 October 2015 00:19:06 Arnd Bergmann wrote:
> > 3. Contact usb list about usbtest ioctl uses and about proposed new ioctl.
> 
> Yes, but don't make this one a priority. Adding a new ioctl is just the
> icing on the cake, and that patch mainly serves to highlight the fact
> that the original API was implemented poorly and how it should have
> been done instead. It's more important for us to avoid making things
> worse with the 64-bit time_t change.
> 

I've given this a little more thought now: I think we should support both
variations of the current interface in both the kernel and in the official
copy of the user space tool, for maximum compatibility.

If we add another ioctl, that means we have to support all three variants
in both kernel and user space for the foreseeable future, that's only
worth it if we can add some real value in the new interface. Instead of
a new ioctl, we could also choose to add a debugfs interface that might
be easier to use. Still, that is only a mild improvement to a rarely used
driver and a lot of work, so don't spend too much time on that one.

	Arnd