Re: [RFC 7/8] fpga-region: add sysfs interface

From: Moritz Fischer <moritz.fischer@ettus.com>
To: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Cc: "Nadathur, Sundar" <sundar.nadathur@intel.com>,
	Alan Tull <delicious.quinoa@gmail.com>,
	Yves Vandervennet <yves.vandervennet@linux.intel.com>,
	"matthew.gerlach@linux.intel.com"
	<matthew.gerlach@linux.intel.com>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	"linux-fpga@vger.kernel.org" <linux-fpga@vger.kernel.org>,
	"Marek Va??ut" <marex@denx.de>
Subject: Re: [RFC 7/8] fpga-region: add sysfs interface
Date: Wed, 22 Feb 2017 09:50:54 -0800	[thread overview]
Message-ID: <CAAtXAHe4qTvEApJFUZt4DKYYVxLGO8jFZPri0o7J_3chsx8uxw@mail.gmail.com> (raw)
In-Reply-To: <20170222164400.GA18745@obsidianresearch.com>

Jason,

On Wed, Feb 22, 2017 at 8:44 AM, Jason Gunthorpe
<jgunthorpe@obsidianresearch.com> wrote:
> On Tue, Feb 21, 2017 at 10:05:42PM -0800, Moritz Fischer wrote:
>
>> That being said older drivers / fpga-mgr  will not deal with newer features.
>> TLV / KV or whatever doesn't change this fact, or am I missing something?
>
> Often a scheme will have an OPTIONAL and REQUIRED flag for each
> value. If a REQUIRED value is present but the parser does not
> support it then the parse fails.

Oh, of course. I'm a dorque :) Obvioiusly better customer experience like that.

> For instance, we could mark Encrypted as required, and a zynq driver
> that does not support the Encrypted tag would not load the bitfile
> rather than try to load it wrongly.

Funny you'd mention that. Thanks to your patch the zynq driver won't ;-)
I ran into that while testing, hehe.

> This can be forced into any of the approaches with various levels of
> hackery.

Yeah doesn't seem to hard,

Cheers

Moritz