Date: Fri, 31 Mar 2017 16:10:09 +0200
From: Greg KH <greg@kroah.com>
To: Wu Hao <hao.wu@intel.com>
Cc: atull@kernel.org, moritz.fischer@ettus.com, linux-fpga@vger.kernel.org,
        linux-kernel@vger.kernel.org, luwei.kang@intel.com,
        yi.z.zhang@intel.com, tim.whisonant@intel.com,
        Enno Luebbers <enno.luebbers@intel.com>,
        Shiva Rao <shiva.rao@intel.com>,
        Christopher Rauer <christopher.rauer@intel.com>,
        guangrong.xiao@linux.intel.com
Subject: Re: [PATCH 02/16] fpga: add FPGA device framework
Message-ID: <20170331141009.GA8141@kroah.com>
References: <1490875696-15145-1-git-send-email-hao.wu@intel.com>
 <1490875696-15145-3-git-send-email-hao.wu@intel.com>
 <20170331061322.GB7621@kroah.com>
 <82D7661F83C1A047AF7DC287873BF1E167C90F1B@SHSMSX101.ccr.corp.intel.com>
 <20170331133109.GB1312@hao-dev>
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On Fri, Mar 31, 2017 at 09:31:09PM +0800, Wu Hao wrote:
> > On Thu, Mar 30, 2017 at 08:08:02PM +0800, Wu Hao wrote:
> > > +#include <linux/device.h>
> > > +#include <linux/module.h>
> > > +#include <linux/slab.h>
> > > +#include <linux/fpga/fpga-dev.h>
> > > +
> > > +static DEFINE_IDA(fpga_dev_ida);
> > > +static struct class *fpga_dev_class;
> > > +
> > > +static ssize_t name_show(struct device *dev,
> > > +			 struct device_attribute *attr, char *buf) {
> > > +	struct fpga_dev *fdev = to_fpga_dev(dev);
> > > +
> > > +	return sprintf(buf, "%s\n", fdev->name); } static 
> > > +DEVICE_ATTR_RO(name);
> > 
> > There already is a name for the device, it's the directory name.
> 
> For current implementation, the directory will have a common name like
> 
> /sys/class/fpga/fpga.0
> /sys/class/fpga/fpga.1
> /sys/class/fpga/fpga.2
> ...
> 
> For the 'name' sysfs interface, driver can put more device specific info
> into this 'name', e.g intel-fpga-dev. Userspace can use this information
> to know which kind of FPGA device it is. e.g if applications read the
> /sys/class/fpga/fpga.5/name as intel-fpga-dev, it means the 5th fpga
> device on the system is a Intel FPGA device, and then application applies
> related method to enumerate the accelerators for it.
> And other existing fpga class has similar sysfs interface too, so I would
> like to keep it aligned with others.

Ok, then document the heck out of this in Documentation/ABI/ which I
don't think you did for the sysfs files you are creating.

thanks,

greg k-h