From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753201AbbCZPJ3 (ORCPT ); Thu, 26 Mar 2015 11:09:29 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:50421 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753062AbbCZPJZ (ORCPT ); Thu, 26 Mar 2015 11:09:25 -0400 Date: Thu, 26 Mar 2015 16:09:20 +0100 From: Greg Kroah-Hartman To: James Hogan Cc: Ralf Baechle , linux-mips@linux-mips.org, linux-kernel@vger.kernel.org, Jiri Slaby , Jason Wessel , kgdb-bugreport@lists.sourceforge.net Subject: Re: [PATCH 9/9] ttyFDC: Implement KGDB IO operations. Message-ID: <20150326150920.GC21726@kroah.com> References: <1422530054-7976-1-git-send-email-james.hogan@imgtec.com> <1422530054-7976-10-git-send-email-james.hogan@imgtec.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1422530054-7976-10-git-send-email-james.hogan@imgtec.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 29, 2015 at 11:14:14AM +0000, James Hogan wrote: > Implement KGDB IO operations for MIPS Fast Debug Channel (FDC). This can > be enabled via Kconfig, which also allows the channel number to be > chosen. > > The magic sysrq hack is implemented in the TTY driver, detecting just ^C > for the KGDB channel, and ^O followed by a letter for the FDC console > channel. > > The KGDB operations are reasonably efficient thanks to the flush > callback, with a 4 byte buffer being used in both directions to allow up > to 4 bytes to be encoded per FDC word. Reading of data for KGDB will > discard any data received on other channels, which clearly isn't ideal, > but given that there is a single FIFO shared between channels we can't > do much better. > > Signed-off-by: James Hogan > Cc: Ralf Baechle > Cc: Greg Kroah-Hartman > Cc: Jiri Slaby > Cc: Jason Wessel > Cc: linux-mips@linux-mips.org > Cc: kgdb-bugreport@lists.sourceforge.net Acked-by: Greg Kroah-Hartman