linux-kernel - Re: [PATCH 4/5] tty/hw: move hardware drivers to drivers/tty/hw

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <201008301725.01424.arnd@arndb.de>
Date:	Mon, 30 Aug 2010 17:25:01 +0200
From:	Arnd Bergmann <arnd@...db.de>
To:	Mike Frysinger <vapier.adi@...il.com>
Cc:	Alan Cox <alan@...rguk.ukuu.org.uk>, Greg KH <gregkh@...e.de>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 4/5] tty/hw: move hardware drivers to drivers/tty/hw

On Monday 30 August 2010, Mike Frysinger wrote:
> 
> On Mon, Aug 30, 2010 at 08:28, Arnd Bergmann wrote:
> > On Monday 30 August 2010, Alan Cox wrote:
> >> > My impression was that it should actually be converted into an hvc
> >> > driver as a cleanup and moved to drivers/tty/hvc. It can probably
> >> > get reduced to one third of its size if you do that.
> >>
> >> Not sure it makes sense - hvc seems the wrong abstraction.
> >
> > It seems to be very similar to hvc_tile.c in purpose, which is
> > the most trivial driver we have. Why would that not work?
> >
> > Most of bfin_jtag_comm is about interfacing with the tty layer
> > and providing a kernel thread to do the polling, which is exactly
> > what hvc_console.c does.
> 
> i have no idea what "hvc" is, but my limited knowledge was that it was
> for large powerpc servers, so i didnt bother looking at it too much.
> i simply wanted a way to create a tty on top of the hardware channel.
> if there is a framework that doesnt break this usage and lets me
> simplify my driver, then either works for me.

HVC started out as the console for large powerpc, but has turned into
a generic framework for TTY drivers that are based on simple read/write
operations with or without interrupts. 

Please take a look at drivers/char/hvc_tile.c, which was added recently
for a scenario quite similar to yours (debug port, not irq).

	Arnd
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/