Date: Thu, 10 Jul 2014 16:16:37 -0700
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Cc: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com>,
        Stephen Warren <swarren@nvidia.com>,
        Heikki Krogerus <heikki.krogerus@linux.intel.com>,
        Jingoo Han <jg1.han@samsung.com>, linux-kernel@vger.kernel.org,
        Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>,
        linux-serial@vger.kernel.org, yrl.pp-manager.tt@hitachi.com,
        Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
        Aaron Sierra <asierra@xes-inc.com>, Jiri Slaby <jslaby@suse.cz>
Subject: Re: [PATCH V8 2/2] serial/uart/8250: Add tunable RX interrupt
 trigger I/F of FIFO buffers
Message-ID: <20140710231637.GB9423@kroah.com>
References: <20140530061617.21929.25777.stgit@yunodevel>
 <20140530061622.21929.82083.stgit@yunodevel>
 <20140710002837.GA5429@kroah.com>
 <20140710153157.57902972@alan.etchedpixels.co.uk>
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On Thu, Jul 10, 2014 at 03:31:57PM +0100, One Thousand Gnomes wrote:
> > I really don't like the way that the tty core has been changed to handle
> > multiple attribute groups, as I feel tty drivers shouldn't be creating
> > "special" sysfs files, depending on what driver is bound to them.
> 
> The intent isn't that it is "special" but that it can be propogated to
> others as and when they wish to provide it.
>  
> > Usually we have handled this using tools like 'stty' and ioctls, right?
> > Surely there is an ioctl to control the interrupt level, right?  Hasn't
> > this been covered before somehow?
> 
> No, and the direction when this started was to use sysfs as we have also
> been moving all the other attributes towards sysfs and has been since
> 2012.
> 
> TTY devices do have lots of strange attributes and right now many of them
> are only programmable by using device tree and rebooting.

Ok.  Hm, there has to be a better way to do the group sysfs file
handling...

Let me work on this tomorrow and see what I can come up with.  We should
be able to use the is_visable() attribute to create/notcreate the
attribute where needed...

thanks,

greg k-h
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