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Date:   Tue, 5 Jan 2021 10:00:50 +0800
From:   Xu Yilun <yilun.xu@intel.com>
To:     Russ Weight <russell.h.weight@intel.com>
Cc:     mdf@kernel.org, linux-fpga@vger.kernel.org,
        linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org,
        trix@redhat.com, lgoncalv@redhat.com, hao.wu@intel.com
Subject: Re: [PATCH v5 2/2] Documentation: fpga: dfl: Add description for DFL
  UIO support
Message-ID: <20210105020050.GA2296@yilunxu-OptiPlex-7050>
References: <1609557182-20787-1-git-send-email-yilun.xu@intel.com>
 <1609557182-20787-3-git-send-email-yilun.xu@intel.com>
 <0f5c3f7c-f367-086f-cd43-d8b23f9a833e@intel.com>
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On Mon, Jan 04, 2021 at 09:19:24AM -0800, Russ Weight wrote:
> 
> 
> On 1/1/21 7:13 PM, Xu Yilun wrote:
> > This patch adds description for UIO support for dfl devices on DFL
> > bus.
> >
> > Signed-off-by: Xu Yilun <yilun.xu@intel.com>
> > ---
> > v2: no doc in v1, add it for v2.
> > v3: some documentation fixes.
> > v4: documentation change since the driver matching is changed.
> > v5: no change.
> > ---
> >  Documentation/fpga/dfl.rst | 24 ++++++++++++++++++++++++
> >  1 file changed, 24 insertions(+)
> >
> > diff --git a/Documentation/fpga/dfl.rst b/Documentation/fpga/dfl.rst
> > index 0404fe6..b8497f3 100644
> > --- a/Documentation/fpga/dfl.rst
> > +++ b/Documentation/fpga/dfl.rst
> > @@ -7,6 +7,7 @@ Authors:
> >  - Enno Luebbers <enno.luebbers@intel.com>
> >  - Xiao Guangrong <guangrong.xiao@linux.intel.com>
> >  - Wu Hao <hao.wu@intel.com>
> > +- Xu Yilun <yilun.xu@intel.com>
> >  
> >  The Device Feature List (DFL) FPGA framework (and drivers according to
> >  this framework) hides the very details of low layer hardwares and provides
> > @@ -502,6 +503,29 @@ FME Partial Reconfiguration Sub Feature driver (see drivers/fpga/dfl-fme-pr.c)
> >  could be a reference.
> >  
> >  
> > +UIO support for DFL devices
> > +===========================
> > +The purpose of an FPGA is to be reprogrammed with newly developed hardware
> > +components. New hardware can instantiate a new private feature in the DFL, and
> > +then get a DFL device in their system. In some cases users may need a userspace
> > +driver for the DFL device:
> > +
> > +* Users may need to run some diagnostic test for their hardwares.
> > +* Users may prototype the kernel driver in user space.
> > +* Some hardware is designed for specific purposes and does not fit into one of
> > +  the standard kernel subsystems.
> > +
> > +This requires the direct access to the MMIO space and interrupt handling in
> This may be better stated as:
> 
> "This requires direct access to MMIO space and interrupt handling from userspace."

Thanks for the correction, I'll change it.

Yilun