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From: Jonathan Corbet <corbet@lwn.net>
To: ksummit@lists.linux.dev
Subject: [MAINTAINER SUMMIT] User-space requirements for accelerator drivers
Date: Fri, 10 Sep 2021 15:00:58 -0600	[thread overview]
Message-ID: <877dfop2lx.fsf@meer.lwn.net> (raw)

There has been a regular disagreement in recent years about whether
drivers for accelerators (such as for the Habana Gaudi device) should be
subject to the same requirements as GPU drivers when it comes to the
availability of a free implementation of the user-space side.  It flared
up again recently:

   https://lwn.net/Articles/867168/

Happily, the Habana situation in particular seems to be resolving
itself:

   https://lwn.net/ml/linux-kernel/CAFCwf119s7iXk+qpwoVPnRtOGcxeuZb3rnihf6NWWoVT-4ODHA@mail.gmail.com/

But even there it is clear that the fundamental question has not yet
been resolved.

This seems like the sort of question that the maintainer summit exists
to address.  Specifically, we could discuss:

 - Under which circumstances should the kernel community require the
   existence of freely licensed user-space code that exercises all
   functionalities of a proposed kernel driver or feature?

 - Are there internal kernel interfaces, such as DMA-BUF or P2PDMA, that
   are only available to drivers with a free user-space implementation?
   Do we need an EXPORT_SYMBOL_USERSPACE_GPL()?

 - What constitutes an acceptable user-space implementation in cases
   where these restrictions apply?

I suspect that more clarity (and fewer arguments) on these questions
would be welcome both within and beyond the development community.

Thanks,

jon

             reply	other threads:[~2021-09-10 21:10 UTC|newest]

Thread overview: 77+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-10 21:00 Jonathan Corbet [this message]
2021-09-10 21:32 ` [MAINTAINER SUMMIT] User-space requirements for accelerator drivers Josh Triplett
2021-09-13 13:50   ` Christian Brauner
2021-09-13 13:57     ` Daniel Vetter
2021-09-14  2:07       ` Laurent Pinchart
2021-09-14 14:40   ` Jani Nikula
2021-09-14 14:45     ` Geert Uytterhoeven
2021-09-14 14:59       ` Jani Nikula
2021-09-14 15:10         ` Geert Uytterhoeven
2021-09-10 21:51 ` James Bottomley
2021-09-10 21:59   ` Alexandre Belloni
2021-09-10 22:35     ` James Bottomley
2021-09-11 14:51       ` Jonathan Corbet
2021-09-11 15:24         ` James Bottomley
2021-09-11 21:52           ` Laurent Pinchart
2021-09-14 13:22             ` Johannes Berg
2021-09-11  0:08   ` Laurent Pinchart
2021-09-10 22:52 ` Mauro Carvalho Chehab
2021-09-10 23:45   ` Josh Triplett
2021-09-10 23:48     ` Dave Hansen
2021-09-11  0:13       ` Laurent Pinchart
2021-09-10 23:55     ` Thomas Gleixner
2021-09-11  0:20       ` Laurent Pinchart
2021-09-11 14:20         ` Steven Rostedt
2021-09-11 22:08           ` Laurent Pinchart
2021-09-11 22:42             ` Steven Rostedt
2021-09-11 23:10               ` Laurent Pinchart
2021-09-13 11:10               ` Mark Brown
2021-09-11 22:51           ` Mauro Carvalho Chehab
2021-09-11 23:22           ` Mauro Carvalho Chehab
2021-09-11 10:31       ` Leon Romanovsky
2021-09-11 11:41         ` Laurent Pinchart
2021-09-11 12:04           ` Leon Romanovsky
2021-09-11 22:04             ` Laurent Pinchart
2021-09-12  4:27               ` Leon Romanovsky
2021-09-12  7:26                 ` Greg KH
2021-09-12  8:29                   ` Leon Romanovsky
2021-09-12 13:25                     ` Greg KH
2021-09-12 14:15                       ` Leon Romanovsky
2021-09-12 14:34                         ` Greg KH
2021-09-12 16:41                           ` Laurent Pinchart
2021-09-12 20:35                           ` Dave Airlie
2021-09-12 20:41                           ` Dave Airlie
2021-09-12 20:49                             ` Daniel Vetter
2021-09-12 21:12                               ` Dave Airlie
2021-09-12 22:51                                 ` Linus Walleij
2021-09-12 23:15                                   ` Dave Airlie
2021-09-13 13:20                                   ` Arnd Bergmann
2021-09-13 13:54                                     ` Daniel Vetter
2021-09-13 22:04                                       ` Arnd Bergmann
2021-09-13 23:33                                         ` Dave Airlie
2021-09-14  9:08                                           ` Arnd Bergmann
2021-09-14  9:23                                             ` Daniel Vetter
2021-09-14 10:47                                               ` Laurent Pinchart
2021-09-14 12:58                                               ` Arnd Bergmann
2021-09-14 19:45                                                 ` Daniel Vetter
2021-09-14 15:43                                             ` Luck, Tony
2021-09-13 14:52                                     ` James Bottomley
2021-09-14 13:07                                     ` Linus Walleij
2021-09-13 14:03                           ` Mark Brown
2021-09-12 15:55                       ` Laurent Pinchart
2021-09-12 16:43                         ` James Bottomley
2021-09-12 16:58                           ` Laurent Pinchart
2021-09-12 17:08                             ` James Bottomley
2021-09-12 19:52                   ` Dave Airlie
2021-09-12  7:46                 ` Mauro Carvalho Chehab
2021-09-12  8:00                   ` Leon Romanovsky
2021-09-12 14:53                     ` Laurent Pinchart
2021-09-12 15:41                       ` Mauro Carvalho Chehab
2021-09-10 23:46   ` Laurent Pinchart
2021-09-11  0:38     ` Mauro Carvalho Chehab
2021-09-11  9:27       ` Laurent Pinchart
2021-09-11 22:33         ` Mauro Carvalho Chehab
2021-09-13 12:04         ` Mark Brown
2021-09-12 19:13 ` Dave Airlie
2021-09-12 19:48   ` Laurent Pinchart
2021-09-13  2:26     ` Dave Airlie

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